Triple oxygen isotope (Δ'¹⁷O) analysis has recently be shown to be a powerful tool for identifying metabolic oxygen signatures in mammalian tooth enamel (Pack et al., 2013; Feng et al., 2022). Atmospheric O₂ is consumed by mammals for metabolic oxidation. The low triple oxygen isotope (Δ'¹⁷O) composition of air O₂ serves as a natural tracer for identifying metabolic oxygen in body water. Bioapatite precipitates in isotopic equilibrium with its parental body water and consequently records information on the air O₂. The Δ'¹⁷O of atmospheric O₂ is directly linked to pCO₂ and gross primary production, hence fossil teeth can be used for paleo- pCO₂ reconstructions.

To provide a modern baseline for this approach, we measured 128 individual mammal teeth for their bioapatite Δ'¹⁷O by automatic BrF₅ laser fluorination. The sample set includes diverse body size with a body mass range from 2 g to 6000 kg and physiology from different habitats. Taxon-specific oxygen mass balance models are developed for resolving principal dependencies and relationships.

The mass balance modelled data for all species agree within uncertainty with the measured data. The results show that Δ'¹⁷O not only correlates with body mass, but also with initial oxygen anomalies of inhaled air O₂, which allows for pCO₂ reconstruction on terrestrial mammalian tooth enamel. This documents the potential of tooth enamel Δ'¹⁷O analysis for metabolic rates of extinct vertebrates and paleoclimate reconstructions, especially for small mammals (Mb < 1 kg).

Pack et al. (2013) GCA, 102, 306–317.

Feng et al. (2022) GCA, 328, 85-102.

Carbonate δ¹⁸O and Δ₄₇ are used to reconstruct paleotemperatures. Because biogenic carbonate does not form in full equilibrium with seawater, species-specific temperature calibration curves are required for accurate temperature estimates. Apparent growth temperatures derived from corals, however, are generally inaccurate due to large and variable kinetic isotope effects, often termed “vital effect”. Triple oxygen isotope systematics can help identify if an organism forms carbonate in equilibrium with ambient water or not and thus if the δ¹⁸O and Δ₄₇ values provide accurate paleotemperatures. In addition, the chemical nature of the “vital effect” can be identified, because individual kinetic effects fall on characteristic trajectories in triple oxygen isotope space.

To examine these concepts a series of cold water and warm water corals as well as brachiopods are analyzed for δ¹⁸O and δ¹⁷O (expressed as Δ’¹⁷O) using the CO₂ spectrometer (TILDAS; Aerodyne Research) installed in Göttingen. Samples formed in equilibrium are expected to fall on the equilibrium curve. Most samples fall below the curve providing evidence that their oxygen isotope composition is biased by kinetic effects. We suggest that the “vital effect” in corals is dominated by a CO₂ absorption effect. Similar conclusions are derived from dual clumped (Δ₄₇ and Δ₄₈) isotope analyses of the same samples [1]. These authors suggested to correct for kinetic effects by back extrapolation to the “dual clumped” equilibrium line. The same concept can be applied in triple oxygen isotope space by back-extrapolation to the “triple oxygen isotope” equilibrium line.

[1] Davies et al. (2022). GCA 338, 66–78.

The reconstruction of Mesozoic seawater temperature is valuable to further understand the link between atmospheric carbon dioxide concentration and earth surface temperature variation. Belemnites are an effective archive for this purpose, owing to their distribution over an extensive latitudinal range in Jurassic and Cretaceous seas. However, uncertainty remains as to whether belemnites precipitate rostrum calcite in oxygen and clumped isotope equilibrium with surrounding seawater. Furthermore, recent study indicates that belemnite calcite may be more susceptible to thermal resetting of ∆₄₇ values through oxygen isotope exchange with internal water than other calcites (Looser et al., 2023).

Here, we demonstrate identification of thermal resetting of ∆₄₇ values in belemnite calcite using a combination of measured δ¹⁸O of fluid inclusions, δ¹⁸O and ∆₄₇ values of belemnite calcite. We then apply dual carbonate clumped isotope thermometry (i.e. the simultaneous measurement of ∆₄₇ and ∆₄₈), to assess the potential importance of kinetic limitations during belemnite biomineralization (Bajnai et al., 2020; Guo, 2020). We demonstrate that Maastrichtian agebelemnites sampled at 4 sites with a range of paleolatitudes from 34 to 45 ˚N, yield ∆₄₇ and ∆₄₈ values that fall on the experimentally derived equilibrium calibration of Fiebig et al., (2021) indicating that rostrum calcite precipitated in clumped isotope equilibrium. ∆₄₇-derived temperatures are combined with other proxy-based reconstructions of Maastrichtian seawater temperature to examine its latitudinal variability.

Microbes, plants and other organisms actively shape the Earth surface by a variety of processes. Current research on modern systems suggests that biota has a significant impact on the mobility of trace elements and there is growing evidence that it may have done so since the dawn of life. The secretion of extracellular compounds that bind strongly to iron and other micronutrients are evolutionary traits that may, besides acquiring bio-essential trace metals, also have helped in tackling with the toxicity of certain heavy metals. An example of such compounds are siderophores, which are produced today by many different plants, microbes and fungi. Besides iron, they promote the (bio)availability of different highly-charged cations in the natural environment.

In paleoclimate studies, the redox-sensitive trace elements Ce and U are commonly used as geochemical proxies (e.g., Ce anomalies, Th-U ratios, stable U isotopes) for reconstructing atmospheric oxygen levels through time. We investigated the effect of siderophores on the mobilization of rare earth elements, Th and U (isotopes) from natural rocks under anoxic, hypoxic and oxic conditions. We show that experimental water–rock interaction with siderophores under strictly anoxic conditions produces positive Ce anomalies – a geochemical signal that is usually attributed to the presence of atmospheric oxygen. Siderophores also influence the Th-U signal, but do not induce a significant U stable isotope fractionation. Thus, oxygen-independent fractionation during geo–bio interaction may hold the potential to use certain trace elements as a bio-proxy in addition to their current use as a redox proxy.

Cherts are sturdy and ubiquitous throughout Earth history and therefore potentially ideal climatic archives, yet their diagenetic formation challenges straightforward interpretations. Previous work shows that oxygen isotope ratios (δ¹⁸O_chert) are not only controlled by seawater T and δ¹⁸O_seawater, but also by basal heat flow (Q) and burial rates, i.e. the diagenetic T-t path (Tatzel et al., 2022).

To strengthen the empirical evidence for the control of Q and burial rates on δ¹⁸O_chert we exploit the geological framework of the Rhenish Massif: During the Lower Carboniferous siliceous sediments were deposited onto stretched continental crust with variable Q across the basin. The opal mud then transformed during burial diagenesis into chert while tectonic nappes were stacked onto the autochthonous sediments during the Armorica- Laurussia collision.

To isolate the effects of the T-t-path on δ¹⁸O_chert we sampled isochronous cherts and siliceous shales from the Northern and Eastern margin of the Rhenish Massif. A decreasing trend in δ¹⁸O_chert from West-to-East (by >6 ‰) testifies to differences in burial rates and paleo-Q. We derive constraints on burial rates from peak diagenetic temperatures using Raman Spectrometry of carbonaceous matter and deconvolve for paleo-Q. Triple oxygen isotope compositions (Δ’¹⁷O) show increasing variations with increasing δ¹⁸O_chert – presumably a reflection of a wider range of diagenetic conditions in low-Q settings.

Tatzel, M., Frings, P.J., Oelze, M., Herwartz, D., Lünsdorf, N.K., Wiedenbeck, M., 2022. Chert oxygen isotope ratios are driven by Earth’s thermal evolution. Proc. Natl. Acad. Sci. 119.

Large megathrust earthquakes like the 2011 Mw 9.0 Tohoku earthquake (Japan) are followed by numerous aftershocks in the subduction zone forearc overlying the seismogenic fault. The aftershocks in the forearc can include normal-faulting events despite the thrust mechanism of the main shock. Postseismic normal faulting has been explained by stress changes induced by the coseismic stress drop along the megathrust. However, details of stress changes in the forearc and aftershock triggering mechanisms remain poorly constrained. Here we use numerical force-balance models combined with Coulomb failure analysis to show that the megathrust stress drop indeed supports normal faulting, but that forearc-wide triggering of aftershocks is feasible within a narrow range of megathrust stress-drop values and forearc stress states only [for details see Dielforder et al., 2023]. We determine this range for the Tohoku earthquake and show that the associated stress changes explain the aftershock seismicity in unprecedented detail. In particular, our analysis reveals that ~78% of the aftershocks and ~92% of the seismic moment release occurred in areas where the Tohoku earthquake caused a stress increase, and that the detailed aftershock distribution was also governed by spatial variability in fault strength and forearc topography. Our findings provide new insights into aftershock triggering and help to understand where aftershocks occur after great earthquakes at subduction zones.

Dielforder, A., Bocchini, G. M., Kemna, K., Hampel, A., Harrington, R. M., & Oncken, O. (2023). Megathrust stress drop as trigger of aftershock seismicity: Insights from the 2011 Tohoku earthquake, Japan. Geophysical Research Letters, 50, e2022GL101320. https://doi.org/10.1029/2022GL101320

Slow-slip events (SSEs), although widely recorded in various convergent margins globally, only recently have been reported in the Eastern Mediterranean, with one of them triggering the 2018 ~M7 Zakynthos Earthquake along the western Hellenic Subduction System (HSS). Here, we explore the distribution, size and duration of SSEs along the HSS and assess their importance in subduction-related strain accumulation and release. To achieve this, we analyse geodetic timeseries from a dense network of permanent GNSS stations on Western Peloponnese, Crete and surrounding islands that collectively span a time-period of ~10 years. We use greedy linear regression techniques to estimate displacement trajectory models for each station and thus we identify transient displacement signals, associated with aseismic processes at depth. To further constrain the spatial extent and size of the SSEs we invert the GNSS transient displacements for variable distributed slip at depth and we, therefore, discuss likely scenarios of aseismic and seismic strain distribution (and partitioning) within the HSS’s complex plate-interface zone.

Central New Zealand (southern North Island/northern South Island) occupies a complex transition from subduction to strike-slip at the southern termination of the Hikurangi subduction zone. This transition was also the site of the 2016 M7.8 Kaikoura earthquake, which is the most complex earthquake ever recorded, involving rupture of over a dozen faults. I will discuss how this transition from subduction to strike-slip occurs, through a joint interpretation of geologic and geodetic data. Approximately 2 cm/yr of convergence is accommodated at the Hikurangi Trough offshore the southern North Island, which decreases rapidly southward offshore the northern South Island (to a few mm/yr), where the majority of the relative plate motion is transferred onto strike-slip faults within the upper plate. This transfer of slip is facilitated via easterly-trending strike-slip faults (such as the Boo Boo fault in Cook Strait). Although the shallow megathrust offshore the northeastern South Island accommodates low rates of convergence, kinematic models based on geodetic data indicate that a large component of relative plate motion must be accommodated on the subduction interface at depth, down-dip of the major upper plate faults. This, along with geodetic evidence for interseismic coupling on the subduction interface beneath the northeastern South Island has implications for the potential southward extent of subduction interface earthquake rupture in central New Zealand. InSAR and GNSS evidence for large amounts of afterslip on the subduction interface following the Kaikoura earthquake also indicates the subduction zone continues as an important boundary well into the northern South Island.

Flexural bending of a downgoing subducting plate in response to forces from slab pull and topographic load leads to foreland basin development in front of growing mountain belts. Many foreland basins worldwide show along-strike variable basin architecture and subsidence history. Various factors such as lateral variations in slab pull, the presence of lateral crustal heterogeneity, slab breakoff and tear propagation have been suggested as drivers. However, the effects of an oblique continental collision on the evolution of foreland basins are largely ignored. In this study, we use 3D thermo-mechanical numerical models coupled with surface processes (i.e., sedimentation and erosion) to simulate an oblique collision. In the initial model, the continental plate margin is placed at an oblique angle relative to the subduction trench and we vary the following parameters: (1) margin obliquity, (2) convergence velocity, (3) age of the subducting oceanic lithosphere, and (4) presence of pre-existing rigid blocks in the subducting plate. Our results show that models with no obliquity (i.e., straight continental margin) create simultaneous along-strike continental collision and foreland basin subsidence. However, higher margin obliquity (≥ 15° ) causes a delay in the along-strike collision and foreland basin development. Our results suggest that the along-strike propagation of foreland basin development is controlled by the initial margin obliquity and plate convergence velocity. Finally, we discuss the implications of our study on the 3D evolution of the Northern Alpine Foreland Basin (NAFB) and intramountain basins within the Betics where along-strike variations of the sedimentary basin architecture are reported.

Das Jura-Museum widmet sich den Fossilien im weltberühmten Solnhofener Plattenkalk. Hier wird ein neues Exponat vorgestellt, dass sich den Solnhofener Plattenkalken über die Fossilien hinaus widmet. Es handelt sich um ein Festgesteins--Transferpräparat aus dem Steinbruch Ettling, das während der Forschungsgrabung angefertigt wurde und die Gesteinsabfolge im Original dokumentiert. Daraus wird ein Exponat, das dem Publikum Einblicke geben soll, wie sedimentäre Abfolgen datiert und interpretiert werden. Der Steinbruch Ettling ist bekannt für seine außerordentlich gut erhaltenen Fische mit Farbmustern. Der einzige Ammonit, der als Altersanzeiger dienen kann, kommt aus einer Bank, die im Transferpräparat enthalten ist. So kann Biostratigraphie anschaulich vermittelt werden. Weitere Forschungsdatenwerden in Zukunft direkt auf das Transferpräparat übertragen. Derzeitige Analysenumfassen mineralogische Zusammensetzung, Nannofazies, Chemostratigraphie und quantitative Auswertungen aus der Forschungsgrabung. Die Ergebnisse, die allein sehr abstrakt wären, sind so anschaulich am Profil vermittelbar. Das Exponat dient somit zur Vermittlung vielfältiger geowissenschaftlicher Ansätze und Fragestellungen weit über den Fossilbestand hinaus und liefert direkte Einblicke in die Forschung.

Ein Museum will eine Öffentlichkeit erreichen. Doch das ist leichter gesagt als getan, denn aus soziologischer Sicht zeigt sich die Öffentlichkeit nicht als monolithischer Block, sondern als ein Konglomerat aus sozialen Milieus, die Informationen sehr unterschiedlich aufnehmen und verarbeiten. Das Wahlkapfteam Barack Obamas z.B. war dementsprechend auf über 80 solcher ÖffentlichkeitEN eingestellt und sprach sie jeweils unterschiedlich an. Wie kann die Soziologie mit ihren Modellen von dem, was man gemeinhin "Gesellschaft" nennt der Wissenschaft, die genau weiß, "wie man mit dem Hammer philosopirt" (Nietzsche) ggf. dabei helfen, ihre Öffentlichkeiten zu erkennen und erfolgreich mit ihnen zu kommunzieren? Dieser Frage würde ich gerne in meinem Beitrag diskutieren.

Kleine Museen mit eingeschränkter Finanzierung können oft nur geringe Mittel aufbringen, um mit weiterführenden Material Vitrinen und Ausstellungsobjekte zu ergänzen, zum Beispiel englische Texte oder Tonmaterial für Sehbehinderte. Um spezielle Zielgruppen, wie z. B. Kinder und Schülerinnen und Schüler anzusprechen und ihnen Sammlungsobjekte zugänglich zu machen, bieten sich kurze Videos an, die wissenschaftliche Zusammenhänge erläutern. Ferner können Forschungsmethoden in solchen Videos erklärt werden. Die Einbindung von ergänzenden Visualisierungen kann u a. über QR-Codes oder an geeigneten Stellen mit Monitoren erfolgen.

Wir präsentieren anhand von Fallbeispielen Ansätze, wie mit geringem technischen Aufwand und weit verbreiteter, zum Teil frei verfügbarer Software ergänzendes Videomaterial erzeugt und in Ausstellungen eingesetzt werden kann. Das Poster bietet über QR-Codes Zugang zu auf diese Art generierte Videodateien.

The application of finely ground silicate minerals to croplands and forests, with the aim of enhancing the rate of natural CO₂ consuming weathering reactions, is receiving attention as a part of climate change mitigation strategies. Yet considerable uncertainty surrounds the quantification of CO₂ removal associated with Enhanced Weathering, and its potential efficacy remains undemonstrated outside of the laboratory. Here, I discuss how the geochemical insights garnered from decades of natural weathering studies provide a pathway towards a strategy for ‘Monitoring, Reporting and Verification’ of CO₂ sequestration. These natural weathering studies have also produced an understanding of what limits silicate weathering in different settings, which can be used to shed light on how deployment strategies, and specifically application sites, can be optimised.

In this work we study critical questions which determine the scale and viability of ocean alkalinity enhancement (OAE): Which coastal locations are able to sustain a large flux of alkalinity at minimal pH and aragonite saturation changes? What is the interference distance between adjacent OAE projects? How much CO₂ is absorbed per unit of alkalinity added? How quickly does the induced CO₂ deficiency equilibrate with the atmosphere?
Using the LLC270 (0.3deg) ECCO global circulation model we find that the steady-state OAE rate varies over 1–2 orders of magnitude between different coasts and exhibits complex patterns and non-local dependencies which vary from region to region. Neighboring OAE sites can exhibit dependencies as far as 400 km or more. We show that near-coastal OAE has the potential to scale globally to several GtCO₂/yr of drawdown with conservative pH constraints, but only if the effort is spread over the majority of available coastlines.
Depending on the location, we find a diverse set of equilibration kinetics, determined by the interplay of gas exchange and surface residence time. Most locations reach an uptake-efficiency plateau of 0.6–0.8mol CO₂ per mol of alkalinity after 3–4 years, after which there is little further CO₂ uptake. Some locations (e.g. Hawaii) take significantly longer to equilibrate (up to 8–10 years), but can still eventually achieve high uptake. If the alkalinity released advects into regions of significant downwelling (e.g. around Iceland) up to half of the OAE potential can be lost to bottom waters.

The seafloor functions as a substantial long-term (>100 yr) carbon sink and reservoir in the form of sedimentary organic particles. Human activities can modify the seafloor's natural carbon sequestration capacity by disturbing the upper sediment layers and thereby altering biogeochemical processes and releasing previously trapped carbon. Yet, the overall magnitudes of the changes in sedimentary carbon pools induced by these processes are not well known and could not be adequately considered in environmental impact assessments so far.

In this study, we quantify anthropogenic disturbances of sedimentary carbon sequestration in the North Sea using a combination of measurement data and numerical modeling. In particular, we examine the effects of bottom-contacting fisheries, sediment extraction, and material dumping. By resolving spatial and temporal patterns of both natural and anthropogenic drivers, we identify areas particularly vulnerable to degradation, representing the most detailed large-scale estimates of human impacts on North Sea sediments to date. Our results indicate that while the impacts of human activities on sedimentary carbon sequestration are comparable in magnitude to natural sedimentation processes, the resulting carbon benefits are considerably lower than previously estimated.

Although remaining uncertainties need to be further confined and missing processes such as ecosystem feedbacks considered, our findings can serve as a useful basis for the consideration of sedimentary carbon disturbance in the context of marine spatial management plans.

The tropics have the potential to capture large amounts of CO2 through enhanced weathering of mafic rocks. This negative emissions technology can be articulated with the needs of the agricultural sector, in particular the large irrigated tropical cropland in the tropics. High-yield agricultural soils in the tropics are acidic. Their acidity is traditionally controlled with lime, which in turn emits CO2. Crushed mafic rocks can be used instead of lime, with the added benefit of not only avoiding the lime emissions, but also capturing CO2. In tropical Colombia, there are extensive plantations of African oil palm, sugar cane, rice, banana, and corn. Nearby, there are large open-cast mining operations that produce massive volumes of mafic and ultramafic rocks as waste product. We are characterizing mafic and ultramafic rocks closest to the potential application sites, as well as the products of their weathering under natural conditions. We are also conducting field experiments with natural soils from areas of active afforestation, as well as in soils degraded by cattle ranching. Both were previously covered by rain forests. In these experiments we are evaluating the reaction rates and efficiencies of mafic and ultramafic rocks under tropical conditions in natural soils. We aim to establish the technical and scientific basis for a process by which the forestry, mining, agricultural, and energy industries in the tropics can reduce their operational carbon footprint, and eventually offer carbon capture bonds in the international market.

It is now well known that limiting the warming of the planet to 1,5°C by the end of the century will require some degree of carbon dioxide removal (CDR) and marine CDR technologies have emerged as a potential solution to mitigate climate change. While marine CDR can be piloted domestically, its maximum efficiency requires international coordination due to transboundary effects. However, the current international legal framework, including the UNFCCC and its descendants, lacks a dedicated regime for CDR, resulting in a plethora of potentially applicable sources of law with different answers on the legality of CDR. Emphasizing the challenges and necessities of coordinating CDR activities on a global level, this presentation addresses the unrealistic optimism of current law to over-rely on clear cut answers from natural sciences. It will explain how the traditional approach of the law needs to be revised to adapt to the scientific realities of climate action. This analysis should provide a reflection on the need for a wider societal debate to solve “trade-offs” issues that lawyers alone are not in a position to solve.

The presentation provides an overview of BGR's deep-sea mineral resource exploration and informs on recent developments in deep-sea mining. Metals such as copper, nickel and cobalt play a vital role in the production of regenerative energies and high-tech electronic products. Currently, these metals are solely extracted from land sources, but increasing global demand has spurred interest in deep-sea deposits located in areas beyond national jurisdiction. Polymetallic nodules, cobalt-rich manganese crusts and massive sulphides found at water depths of 1 to 5 kilometers are seen as potential sources of such raw materials. Germany, as an industrial country with high raw material demands, heavily relies on metal imports. As a potential measure to reduce dependence and secure supply, Germany has invested actively in the exploration of marine mineral deposits and their environment in the eastern Pacific and southwestern Indian Ocean during the last two decades. The International Seabed Authority (ISA) is currently negotiating regulations for the mining of these resources (“Mining Code”). At the moment, the focus is on adopting regulations for polymetallic nodule mining, possibly by 2024. However, companies could potentially already submit mining applications today, to be considered by the Council despite the absence of a full set of binding regulations. Significant progress has recently been made in overcoming the technical challenges of mining the deep sea. Several contractors have successfully tested mining systems and are currently monitoring the resultant impacts on the environment and the biodiversity.

Two zoned inactive chimney samples from the SMAR 26°S (Xunmei) hydrothermal field were studied petrographically and by in-situ LA-ICP-MS analysis. Morphologically different pyrites precipitated with increasing temperatures from the outermost chimney wall to intermediate zone, then to the inner zone, and finally to interstice pore fillings which represents the late mature stage. The distribution of trace elements in pyrites across the chimney indicates a strong dependence on time, temperature, and associated sulfide minerals. The variation of trace elements in different paragenetic stages of pyrite reveals that the hydrothermal system most likely evolved from low-temperature low-chloride liquid-dominated fluids (enriched in Zn, Cd, Tl, Ag, Pb, Mn, Mo, and V) to higher temperature, vapor-dominated fluids (Cu, Au, Te, and Bi), probably representing magmatic volatiles, and then to high-temperature fluids (Co and Se). In the waning stage of the hydrothermal system, circulating hot fluids in auxiliary conduits were depleted in most trace elements. LA-ICP-MS time-depth profiles reveal that Co, Se, and Mo are present mainly in lattice substitution, whereas Cu, Zn, Cd, Tl, Ag, Te, and Bi are related to micro-/nano-inclusions. Profiles for As, Pb, Au, and Sb can be either smooth or irregular, indicating both lattice substitutions and inclusions. Adsorbed films on pyrites control the distribution of V and Mo. To conclude, the behavior of trace elements is strongly associated with the fluid evolution during chimney growth, where trapping of micro-/nano-inclusions and surface adsorption are seen more frequently at the low-temperature stage, whereas lattice substitutions are dominant at elevated temperature stages.

The Permian-Triassic mass extinction, one of the most severe biotic crises in Earth's history, has been attributed to sharp heating (nearly 15°C in low-latitude areas) initially triggered by massive volcanic eruptions of the Siberian Traps in the latest Permian. Drastic environmental changes have been identified worldwide, both in the sea and on land. However, the connections of global palaeoclimate changes, particularly their detection in complex terrestrial systems, remain debatable. Here, based on sedimentological and geochemical data and state-of-the-art modelling from North China, we emphasise the drastically deteriorated palaeoenvironments (e.g. unstable, drought and intermittent heavy precipitation) under a regime of sharp heating, mass wasting and acid rain on land may be significant causes of the mass killing events near the end-Permian and the subsequent Early Triassic long-lasting stressed terrestrial palaeoclimate that delayed the recovery of life. Understanding the Permian-Triassic hyperthermal crisis may also provide critical insight into similar events of different magnitudes in Earth's history, and could inform our near future, in the context of anthropogenic warming and our rapidly changing planet.

The Karoo Supergroup of South Africa contains extremely rich palaeontological record, including evidence of the largest mass extinction in history, the end-Permian extinction (±251.9 Ma). The recovery of terrestrial ecosystems from this mass extinction is an active area of research and one of South Africa’s most important contributions to the field of palaeontology. The farm Driefontein 11 in the Free State Province preserves an Early Triassic (upper Olenekian) fossil lagerstattë in the Burgersdorp Formation of the Karoo’s Beaufort Group . Driefontein yields tens of thousands of body and trace fossils. These fossils range in size from sub-mm scale teeth and invertebrates to bones of large temnospondyls and archosauromorphs. Despite the importance of these fossils, the fauna of Driefontein remains incompletely known – reflecting the sheer numbers of specimens (+- 30 000 coprolites alone) as well as the fragmentary and/or fragile nature and microscopic size of many of the remains. Here, we use a multiresolution (42µm to 1.14µm) approach with propagation phase contrast X-ray synchrotron micro computed tomography on the newly installed beamline, BM18, at the European Synchrotron and Radiation Facility, to investigate all trophic levels of Driefontein. We use this large dataset of high-resolution scans to investigate various aspects of organismal biology, including growth history, functional morphology, and comparative anatomy. This study contributes to our knowledge of the recovery of terrestrial ecosystems after the largest mass extinction in history, the end-Permian extinction, and highlights the importance of Driefontein 11 as a site for future research in the field of palaeontology

Following the end-Permian biotic crisis, reptiles rapidly diversified and dispersed across the globe at the beginning of the Triassic Period. Non-mammalian synapsids became much less abundant and had massive losses in diversity during the end-Permian event. To date, the fossil record of continental tetrapods has largely been restricted to the Karoo of South Africa and European Russia. In the Central European Basin, Early and early Middle Triassic continental red beds are collectively referred to as the Buntsandstein Group. Whereas the strata of the Lower Buntsandstein are largely unfossiliferous, those of the Middle and Upper Buntsandstein have yielded many tracks and trackways representing a great diversity of tetrapods and occasionally skeletal remains of tetrapods. Temnospondyl stem-amphibians were common with a variety of ecomorphs. A sandstone quarry at Rotfelden in the Black Forest region (Germany) exposed a 6-to-8-m-thick section within the top of the Röt 4 Subformation. Tetrapod remains have been recovered from several horizons in this section. Previously, Amotosaurus rotfeldensis, a tanystropheid archosauromorph and the temnospondyl Eocyclotosaurus lehmani have been reported from this locality. New discoveries include a new Euparkeria-grade archosauriform and a rhynchosaur. The latter is documented by a group of three juvenile skeletons. The absence of unambiguous records of non-mammalian synapsids in the Buntsandstein is possibly related to environmental factors. The growing number of tetrapod taxa from the Buntsandstein suggests that assemblages of continental tetrapods had already recovered to a considerable extent 6-7 million years after the end-Permian extinction.

Crocodylomorpha, the crocodylian stem-lineage, is the only pseudosuchian clade that survived into the Jurassic. Its earliest members, the non-crocodyliform crocodylomorphs or ‘sphenosuchians’, were terrestrial and mostly small-bodied (<2 m long). A redescription of both known European ‘sphenosuchian’ taxa is provided, Terrestrisuchus gracilis from the Late Triassic (Norian-Rhaetian?) of southern Wales, and Saltoposuchus connectens from the Norian of southwestern Germany. Terrestrisuchus and Saltoposuchus can clearly be distinguished based on many character states, contrary to some previous hypotheses. A new phylogenetic analysis finds that both taxa form a clade of gracile, long-legged crocodylomorphs, identified as Saltoposuchidae, together with Litargosuchus leptorhynchus. Analysis of a µCT-scan provides a virtually complete threedimensional reconstruction of the Terrestrisuchus braincase. The quadrate only forms a small, unfused contact with the prootic, contrary to later crocodylomorphs in which the braincase is heavily fused to surrounding cranial elements. The posterior skull region is extensively pneumatised by, among others, large pre- and postcarotid recesses on the parabasisphenoid and a large pneumatic cavity within the articular of the mandible, revealing extensive braincase pneumatisation occurred early within Crocodylomorpha. Terrestrisuchus preserves an ossified basihyal and scleral ring, the latter representing the first occurrence among non-bird-line archosaurs. Based on phylogenetic flexible discriminant analysis (pFDA) of the relative dimensions of the sclerotic ring and orbit, Terrestrisuchus was likely active in a range of light levels. Histological long bone sections of both Terrestrisuchus and Saltoposuchus reveal highly vascularized fibrolamellar tissue, indicating sustained high growth rates and thus high resting metabolic rates and active lifestyles for saltoposuchids.

After the devastating Permo-Triassic Mass Extinction, several new groups of large predators invaded the sea in the early part of the Triassic, including sauropterygians, ichthyosauromorphs and thalattosaurs. Among these predators, sauropterygians are the most abundant group in terms of the generic/species diversity. Here we report a new species of Pachypleurosauria (Sauropterygia: Eosauropterygia) from a recently discovered Lagerstätten in the Upper Member of Anisian Guanling Formation. The only known specimen of the new species was collected from Muta village, Luxi County, Yunnan Province, South China. Our new phylogenetic analysis based on a novel data matrix recovered the new taxon as a sister group to Dianmeisaurus. The new phylogenetic analysis also collapsed the monophyly of traditionally recgonized Eusauropterygia. Pistosauridea, Majiashanosaurus, and Hanosaurus comprise the consecutive sister groups to a new clade including Pachypleurosauria and Nothosauroidea. A monophyletic Pachypleurosauria, of which the clade consisting of Dianmeisaurus and Panzhousaurus occupy the basal-most position, is recovered by this study. The clade consisting of Dawazisaurus and Dianopachysaurus forms the sister group to remaining pachypleurosaurs included in this study. Since Dianmeisaurus, Panzhousaurus, Dawazisaurus and Dianopachysaurus are all exclusively known from South China, we suggest that pachypleurosaurs had a paleobiogeographic origin in the eastern Tethys.

The evolution of terrestrial life was as profoundly affected by the end-Permian mass extinction as life in the sea. The recovery of life in the Triassic represented much more than simply a return to pre-extinction conditions, but in fact an entirely new world was ushered in. The generalized replacement of synapsids by archosauromorph reptiles had long been recognized, together with the rise of the dinosaurs to ecological dominance and origins of many modern groups including lissamphibians, turtles, lizards, crocodilomorphs, and mammals. In addition, all the new larger tetrapods had switched from a sprawling posture before the crisis to an erect posture and parasagittal gait afterwards, and this hints at higher activity levels. This is confirmed by the more recent discovery that many of the Triassic archosauromorphs had indicators of endothermy (warm-bloodedness) in their bone histology, and that these Triassic tetrapods also had insulating dermal structures: hair in synapsids and feathers in dinosaurs, pterosaurs and their ancestors. All these indications of endothermy are debated and yet to be confirmed by further study, but they suggest an overall increase of energy in ecosystems, a general speeding up of life as competition and predation increased. Also, it means that these tetrapods were consuming more energy than their Permian forebears. In many ways, these discoveries suggest a macroevolutionary model equivalent to the Mesozoic Marine Revolution, in which Mesozoic marine life was more active and more meaty than much if Palaeozoic marine life.

Many rifted margins are thought to have formed in areas that have previously experienced subduction and orogenesis. Yet, our understanding of how structural and thermal inheritance from preceding convergence affects rifting is still incomplete. We use 2D thermo-mechanical numerical models to investigate how the size of a collisional orogen affects the style of subsequent continental rifting. Our models build an orogen through subduction and collision before the onset of rifting. We focus on the deformation style of the resulting rifted margins and the degree in which inheritance is utilized.

We find that the style of extension changes with the size of the orogen. A narrow orogen produces a narrow margin on the side of the overriding plate with core-complex-style reactivation of the subduction interface while a large amount of oceanic material is preserved in the conjugate margin. In contrast, wide orogens localize rifting away from the subduction interface: the subduction interface is temporarily reactivated, but deformation quickly shifts to the thick orogenic assembly resulting in wide rifted margins. Ductile deformation in the lower crust promotes localization of simultaneously active conjugate shear-zones in the brittle crust above. Rifting in these experiments occurs within the subducting plate.

Our results demonstrate a wide range of features that can form in the presence of inherited compressional structures and emphasise the importance of taking the deformation history into account when trying to understand the evolution of continental rifting.

The South China Sea experienced Cenozoic rifting in a region that was previously part of a Mesozoic Andean-type orogeny, which presumably had resulted in structural, compositional, and thermal inheritance. Recent studies using seismic profiles, drill cores, and geochronological analysis have revealed evidence for such heterogeneous pre-rift lithosphere in the South China Sea (Fan et al., 2017). Here, we further investigate the impact of orogenic inheritance on rift evolution using a numerical forward model that integrates both geodynamic and landscape evolution software (Neuharth et al., 2022). By varying our velocity boundary conditions over time, the model encompasses first continental collision, followed by post-orogenic collapse, continental rifting, and final lithospheric breakup. The model is constrained by observed crustal thicknesses, cooling history, and lithosphere-asthenosphere boundary depth, and successfully reproduces realistic orogenic topography, thrust fault distribution, and rifted margin of the SCS.We find that during orogeny, crustal thickening leads to the development of inherited weaknesses in the modelled crust. From orogenic collapse to continental rifting, pre-existing thrust faults are reactivated and serve as nucleation sites for normal faults, which interact with later rift-related normal faults to modify the regional stress field. The modeling results demonstrate that pre-existing thrust faults and a ductile lower crust play a crucial role in shaping the wide rifted margin of the SCS. We infer from our results that the location of crustal breakup is often influenced by these inherited structures. These regions have typically undergone thermal weakening, which further facilitates the process of crustal breakup during rifting.

Many large sediment-hosted clastic-dominated (CD) base metal deposits occur in failed continental rifts and the passive margins of successful rifts, e.g., in the MacArthur Basin, Australia, and in the Selwyn Basin in Canada. Continental rifts and their margins provide a specific mix of higher temperatures and heat flows, fault networks facilitating fluid flow, sediment input from the generated topography, and ocean water contributing pelagic sediments and sulfates. The large-scale geodynamics thus provide the necessary ingredients for metal leaching, with metal deposition then occurring on much smaller spatial and temporal scales.

To identify the specific geodynamic conditions conducive to large CD-type deposit formation, we numerically model 2D rift systems from inception to break-up with the geodynamic code ASPECT (Heister et al. 2017) coupled to the landscape evolution model FastScape (Braun and Willett 2013; Neuharth et al. 2022). With high-resolution (~300 m) simulations, we investigate how rift type (e.g., wide versus narrow), the presence of a craton, and the efficiency of erosional and depositional processes affect the formation of potential source and host rock domains. We subsequently analyse the optimal alignment of these regions where metals are leached and deposited, respectively, with faulting events providing fluid pathways between them. For these favorable co-occurrences, we estimate the potential size of metal deposits and identify those conditions that predict the largest deposits.

Braun and Willett. 2013. Geomorphology 180–181. 10.1016/j.geomorph.2012.10.008.

Heister et al. 2017. Geophys. J. Int. 210 (2): 833–51. 10.1093/gji/ggx195.

Neuharth et al. 2022. Tectonics 41 (3): e2021TC007166. 10.1029/2021TC007166.

Present spatiotemporal variations of hydrothermal fluxes in the modern and recent ocean provide an observational snapshot of the dynamic interaction between the tectonics of ocean basins and submarine hydrothermal systems. In order to support the understanding of feedbacks between tectonics and the life cycle of hydrothermal systems, we discuss the mechanical, fluid flow and heat flux patterns in a coupled ThermoHydroMechanical model at the ocean basin scale. The case study is an ultra-slow spreading basin, evolving from the initial rifting stages up to the ridge formation. Heat release by plastic deformation at fractures and faults, exothermic serpentinization reactions, sensible and latent crystallization heat from magmatic emplacement and radiogenic heat provide different energy-source signatures promoting hydrothermal activity. The large basin-scale domain allows us to navigate through the evolution of the modelled concurrent hydrothermal systems, emerging and decaying in consonance with the tectonics and the energy-sources. We discuss how the evolving permeability field in crust and sediments exerts a strong control on the hydrothermal circulation, and describe the dynamics of reorganization patterns in fluid flow in response to the mechanical strains and heat sources.

Understanding how normal fault networks initiate and evolve is important for quantifying plate boundary deformation, assessing seismic hazard and finding natural resources. State-of-the-art numerical forward models treat faults as finite-width shear zones, not as discrete entities. To better understand fault system dynamics over geological scales, we develop workflows to isolate individual faults and their role in shaping the fault network.

We present 3D numerical rift models of moderately oblique extension using the ASPECT software. These models reproduce the thermo-mechanical behavior of Earth's lithosphere and simulate fault system dynamics from inception to breakup accounting for visco-plastic rheology, strain softening and surface processes. We extract surficial fault systems as a hierarchical, time-dependent 2D network of nodes, edges and components representing individual faults.

We find that the initial fault network forms through rapid fault growth and linkage, followed by competition between neighboring faults that leads to their coalescence into a stable network. At this point, modelled normal faults continue to accumulate displacement but do not grow any longer. As deformation localizes towards the center of the rift, the initial border faults shrink and disintegrate, being replaced by new faults in the center of the rift. The longevity of faulting is thereby controlled by crustal rheology and surface process efficiency. Quantitative analysis of fault evolution allows us to deduce fault growth and linkage as well as fault tip retreat and disintegration in unprecedented detail.

The App UmweltNAVI Niedersachsen (see the poster in session "4.10" or https://umwelt-navi.info/) communicates geospatial data to a broad user community of education, individuals or experts. In order to adequately present the data in a mobile context, the data must be harmonized, transformed, and combined with other sources. To achieve this, an infrastructure was created that allows editors to integrate data sources and enrich them with information. For example, Web Feature Services, ESRI Shapefiles, SensorThings APIs (STA) are under the data sources. A GUI-guided transformation process enables the mapping of raw data to the harmonized data schema. For the presentation, complex data is simplified, data reconciliation with additional data sources (i.e. Wikipedia or Observation.org) is performed, and the resulting data is stored in a scalable backend. Currently, the database contains 1.8 million records from 57 regional and national data sources and 178,000 images.
Only open source or freely usable software components are used, such as Elasticsearch, Postgres/PostGIS, Airflow or Directus. The delivery layer is designed redundantly for high-performance, fail-safe operation.
A standards-compliant interface (OGC-API Feautures) is being planned to provide access to the data for further processing.
The project was initiated by the Lower Saxony Ministry for the Environment, Energy and Climate Protection in Germany and was implemented together with the companies Bearingpoint and wemove digital solutions. The principle of presenting geodata can also be applied to other areas. The software is basically available for subsequent use.

The Global Heat Flow Database serves as a valuable resource for researchers studying Earth's thermal regime. However, accessing and analyzing this vast collection of geothermal data is presently challenging and limits its widespread utilization. To address this, we present a new online application to the international heat flow community, facilitating seamless discovery, access and analysis of the data. Developed within the DFG-funded World Heat Flow Database Project, it complements the evaluation of existing data and development of a new, collaborative metadata schema for heat flow data.

Our application offers an intuitive interface, allowing researchers to efficiently search, retrieve, and visualize heat flow measurements worldwide. It supports advanced search functionalities that enable users to filter data based on geographical locations, geological parameters, measurement techniques, etc. Integration of powerful data visualization tools allow users to generate maps, plots, and graphs for visual exploration and interpretation. Furthermore, the application incorporates domain relevant statistical analysis functionalities, empowering researchers to perform trend analyses and other statistical assessments directly within the platform.

Our application also aims to foster collaboration within the international heat flow community. We incorporate features such as user profiles, discussion forums, and the ability to contribute new data or review existing records. Overall, we hope to bridge the gap between heat flow specialists and valuable geothermal data by providing an innovative and inclusive platform. We believe this tool will significantly enhance scientific investigations into the Earth's thermal regime and serve as a catalyst for further breakthroughs in the understanding of geothermal processes.

Within the EMODnet Geology project BGR is leading the Workpackage Seafloor geology with the aim to compile and harmonise data of the pre-Quaternary and Quaternary off-shore geology and geomorphology of the European Seas, and finally publish the results according to FAIR data principles. The data are assembled from 36 EMODnet Geology partner organisations and derived mostly from geophysical surveys (e.g. echo soundings) and sampling (e.g. drilling or dredging). Major challenges pose the heterogeneity of the provided data regarding terminology, geometry, level of detail, age of datasets and technical conditions:

• terminology. The participating partners use their own national or regional classification systems and description;
• geometry: artificial discrepancies at EEZ-boundaries;
• scale: some regions are investigated in comparatively high detail while others are mapped in overview scales;
• age: often recently mapped units need to be integrated with data resulting from earlier mapping campaigns;
• heterogeneous technical conditions within partner organisations.

In order to ensure data interoperability and create the maps layers in a largely harmonized, unified manner, the project requires common standards e.g.

• controlled vocabularies, optimally based on existing standards such as INSPIRE or CGI-GeoSciML terminology,
• a straightforward data model and
• a pragmatic approach that takes into account the realities of the project partners.

This presentation will demonstrate the methodological approach to collate and combine data, information and knowledge from over 30 international partners and the challenge to develop, integrate and publish largely harmonized map layers of the off-shore geology of Europe and beyond.

The Federal Waterways Engineering and Research Institute acts as a consultant for and supports the Federal Ministry of Digital and Transport (BMDV) and the Federal Waterways and Shipping Administration (WSV) in navigation-related water engineering tasks. It creates and uses large volumes of scientific data like digital elevation models, simulation results, monitoring data, etc. as part of these activities. The description of this data with metadata is an essential prerequisite for its long-term storage, publication, retrieval and reuse. The requirements for metadata management were implemented with the INGRID software. INGRID offers various interfaces for capturing and processing metadata. It behaves format-agnostic, so different metadata formats can be processed.

The requirements for metadata processing at BAW are quite extensive and differ from the possibilities of usual geodata portals. As a result, custom fields and data classes have been defined in the metadata model. The ISO19139 metadata is used for transferring metadata to external geodata portals. A DOI data record can be generated from the metadata, which can in perspective also be registered automatically at datacite.org. To ensure the description of simulation results with metadata, the delivery of metadata together with data is firmly established in the workflows for data archival and publication.

The presentation describes the requirements for metadata processing, the basic structure of the application, and discusses the life cycle of metadata.

Paleo-CO₂ reconstructions are integral to understanding the evolution of Earth system processes and their interactions given that atmospheric CO₂ concentrations are intrinsically linked to planetary function. Furthermore, past periods of major climate change provide unique insights into the response of land-atmosphere-ocean interactions to warming induced climate change, in particular for times of pCO₂ comparable to those projected for our future. How well the past can inform the future, however, depends on how well paleo-CO₂ estimates are constrained. In this talk, I will first discuss approaches to reconstructing paleo-CO₂ concentrations, the challenges of constraining the uncertainty of these estimates, and the implications for constraining critical issues such as climate sensitivity. I will introduce a new community initiative, CO₂PIP, focused on advancing the reconstruction of paleo-CO₂ through modernizing of existing records and quantifying the representation of CO₂ proxy sensitivities to environmental and ecophysiological conditions and processes that govern the CO₂ signals. I will then focus on a deep-time glaciated period (the late Paleozoic Ice Age), characterized by pCO₂ fluctuations within the range of Quaternary levels to those projected by socio-economic emission scenarios of this century, as well as defined by CO₂-driven abrupt warmings that led to major changes in environmental conditions in the oceans and on land. An integrated multi-proxy data-modeling approach to investigating this deep-time icehouse provides a framework to evaluate the mechanistic linkages between processes and to conceptualize the collective data set. It further reveals the underlying processes linking pCO₂ and environmental changes and documents the sensitivity of Earth System modeled atmospheric and oceanic circulation to changing pCO₂. Application of paleo-CO₂ and fossil plant morphologic and biogeochemical data to process-based ecosystem modeling documents physiological responses to CO₂ and suggests ecosystem-scale vegetation-climate-CO₂ feedbacks that would have influenced water cycling, surface runoff and weatherability, and led to major changes in organic carbon burial, and in turn atmospheric pCO₂.

The lithium isotopic composition (δ⁷Li) of marine carbonates is known as a proxy for the chemical weathering intensity of silicate rocks. To evaluate the role of weathering as a sink for atmospheric CO₂ during the Late Cretaceous, we generated a 20 Ma δ⁷Li record (86.3–66.0 Ma) using chalk from Northern Germany as an archive. The late Santonian to Maastrichtian record shows an overall increase of ~4.5‰ with superimposed increases in the late Santonian, early Campanian and across the Campanian–Maastrichtian transition.

The overall increase in δ⁷Li fits with the Late Cretaceous increase in seawater ⁸⁷Sr/⁸⁶Sr. Further, the δ⁷Li record strongly resembles both the evolution of deep-sea temperatures based on benthic oxygen isotopes and modeled changes in the rate of seafloor spreading. Thereby, increases of δ⁷Li in the early Campanian and across the Campanian–Maastrichtian transition correspond to major sea level falls, and the latter with a negative δ¹³C excursion.

These coherences allow three interpretative approaches: (1) Climate cooling controlled the weathering congruency and the magnitude of Li isotope fractionation by clay mineral formation on the continents. (2) Lowland exposure promoted erosion together with enhanced soil and clay formation after sea level falls. (3) A temperature-dependent fractionation during low-temperature basalt alteration affected the seawater δ⁷Li signal in a time, when more fresh oceanic basalts where available due to higher spreading rates. The best possible interpretation for the Late Cretaceous δ⁷Li record and the often-neglected aspects of basalt alteration and reverse weathering need to be further assessed and discussed.

The evolution of the seawater Lithium isotope composition (δ⁷Li_SW) depends on the prevalent weathering regime. To reconstruct δ⁷Li_SW, and thus, weathering congruency, two main archives are widely used: calcareous fossils and bulk carbonate sediments. Either of these archives has its strong and weak points. While carbonate sediments are prone to diagenesis and clay contamination, biogenic skeletons may exhibit strong vital effects on δ⁷Li_SW. Here, we present δ⁷Li_SW data for the mid-Cretaceous derived from various biogenic carbonates such as bivalves (mainly rudists), cephalopods, and brachiopods from well-known sample sites across Europe.

Additionally, we assessed the extent of taxon-specific vital effects on δ⁷Li for well-preserved Albian molluscs from Madagascar (Mahajanga Basin, age 110.5 +/-0.5Ma) and compared them with data for modern taxonomic groups.

Our most complete data set derives from rudist shells (mainly requieniid rudists) from the mid-Barremian to early Aptian sample locations of Sausset (Urgonian Limestone Formation, France), Ericeira (Crismina Formation, Portugal), Kanfanar (Kanfanar unit, Croatia), and Miravete (Villarova de los Pinares Formation, Spain). We compare their δ⁷Li compositions and trends therein with that of cotemporaneous carbonate-rich sediments. We provide preliminary δ⁷Li_SW for several time intervals which range between 22-25‰ on average with values exceeding 30‰ in the late Barremian.

Relative to published bulk carbonate data, we observe a systematic offset for rudist-shell δ⁷Li values of 3-8‰ towards heavier values. We assign this offset to vital effects similar to those known for modern calcitic molluscs.

Understanding modern species´ ecological preferences and distribution are prerequisites for their application as proxies in paleoenvironmental reconstructions. This knowledge is, however, missing for the majority of tropical species. In order to contribute to close this gap we characterize the ostracod fauna of Lago Enriquillo in the Dominican Republic. Located in the Main Development Region of North Atlantic tropical storms it has experienced rapid water level fluctuations in the past that are assumed to be related to storm activities. This highlights the relevance of the lake for reconstructions of changes in precipitation and storm activity. Living ostracods inhabiting Lago Enriquillo were analyzed in March and September (dry and rainy season) 2022 with the aim to understand their temporal and spatial distribution and changes in morphological characteristics (valve size). Lago Enriquillo is a warm (27.8-33.8°C), mesohaline (43.7-46.3 psu) and generally slightly alkaline lake (pH: 7.5-8.1) with a max. water depth of 25 m. The spatially variable ostracod fauna is composed of Cyprideis similis, Perissocytheridea cribrosa and Thalassocypria sarbui. The three species reflect the lake’s seasonality differently in terms of their morphology and population structure. C. similis occurred continuously but is smaller in spring than in autumn. P. cribrosa inhabits the lake only in autumn and shows a distinct distribution dominating littoral areas with seasonal freshwater inflow. T. sarbui forms larger populations only in spring and forms only tentative size clusters. Their occurrence is restricted to water depths above (temporary) minima of oxygen (below 10 – 14 m).

Driving factors of shell growth of sub-fossil Glycymeris nummaria shells deposited by high energy events into layers at the Atlantic coast of the Iberian Peninsula were investigated by stable isotope analysis and analysing their growth patterns.

High energy events deposited layers of cockles along the coast of Cádiz Bay during the Roman Period (313 ± 114 AD) and the Dark Ages (648 ± 108 AD) (Gutiérrez-Mas, 2011). The climate fluctuation of the region between these two periods was largely investigated by analysing sediment cores from the pro-deltas on the Iberian margin (e.g. Bartels-Jónsdóttir et al., 2015), Glycymeris shells, however can provide seasonal data of temperature change and the seasonality in chemical characteristics of the marine ecosystems. Comparing the paleotemperature data reconstructed from oxygen isotope ratios of seasonally sampled shell carbonate indicates no significant cooling for the ‘Dark Ages Cold Period’ (DACP) for the Cádiz Bay. The seasonality of carbon isotope ratios however showed distinct changes between the Roman Period and the DACP. Seasonal maxima of δ¹³C values were twice as higher during the DACP which indicates seasonally intensified biological fractionation connected to enhanced primary productivity. This agrees with other studies implying intensified coastal upwelling during the DACP along the Iberian Peninsula, while they observe no significant cooling of the sea surface (Bartels-Jónsdottir et al. 2015). This case study adds to the growing number of evidence that the DACP can not be interpreted as a Europe-wide cooling event as it affected southern regions differently.

The triple oxygen isotope composition (δ¹⁸O and ∆’¹⁷O) of atmospheric CO₂ provides valuable information about CO₂ sources and carbon exchange fluxes between atmospheric reservoirs [1-2]. For example, stratospheric CO₂ has a large positive ¹⁷O-anomaly due to photochemical processes. The ∆’¹⁷O of tropospheric CO₂ is primarily influenced by carbonic anhydrase-catalyzed oxygen isotope exchange between air CO₂ and water in vegetation, resulting in an air CO₂ ∆’¹⁷O mainly governed by the isotope composition of local meteoric water. Additionally, CO₂ from fossil fuel combustion processes shows a negative ¹⁷O-anomaly inherited from the isotope composition of atmospheric O₂ [3].

Starting in April 2023, we conducted automated triple oxygen isotope measurements of air CO₂ in Göttingen using tunable infrared laser direct absorption spectroscopy (TILDAS; Aerodyne, USA) coupled with a custom-built inlet system. The internal error of the ∆’¹⁷O measurements was < 10 ppm and of the δ¹⁸Omeasurements < 0.01‰.

In this report, we present our initial results and discuss the contribution of various reservoirs to the ∆’¹⁷O of atmospheric CO₂ in Göttingen. We also examine daily and seasonal variations observed in our data.

[1] G. Koren et al., J. Geophys. Res. Atmos. 124, 8808–8836 (2019).

[2] M. E. G. Hofmann et al., Geochim. Cosmochim. Acta. 199, 143–163 (2017).

[3] B. Horváth, M. E. G. Hofmann, A. Pack, Geochim. Cosmochim. Acta. 95, 160–168 (2012).

The Alps are one of the best studied orogens, but arguably also one of the most disputed ones. Several major geodynamic processes remain unclear, such as the mechanism of (U)HP rock exhumation, for example exhumation during plate divergence or syn-convergent exhumation, or the mechanism of subduction initiation, for example vertically forced initiation by gravitational sinking or horizontally forced initiation due to plate convergence. The Tibetan plateau is currently the highest continental plateau and its first-order geometry is well constrained. Spatial variations in topography and crustal thickness can be used to estimate horizontal forces per unit length from spatial variations in gravitational potential energy per unit area. Knowledge of forces and stresses is essential to understand geodynamic processes. However, maximal magnitudes of differential stresses occuring locally within the crust remain disputed and range from ca. 10 MPa to several hundreds of MPa. Deterministic mathematical modelling based on the fundamental laws of physics is one method to test different geodynamic hypotheses and quantify potential stress magnitudes. Here, we employ 2D petrological-thermo-mechanical numerical simulations to the Alpine orogeny to test the two hypotheses of horizontally forced subduction initiation and syn-convergent exhumation with a single simulation and with petrological and geochronological data. We use 3D mechanical numerical calculations for the Tibetan plateau, to quantify the impact of (i) a realistic double curvature of the Earth’s crust, (ii) the effective viscosity of the crust, (iii) the stress exponent of a power-law flow law and (iv) the plateau’s corner regions on the 3D crustal stress field.

Recent decades have been connected with an impressively accelerating pace in the development and availability of new analytical techniques to earth scientists. Interestingly, the smaller the scale considered, the more heterogeneous an apparently uniform rock sample is. This heterogeneity is not only characterized by variation in chemical composition but also in mechanical properties. The mechanical effects may influence element transport and mineral assemblage in rocks which can, in turn, significantly control the mechanical-chemical coupling rates and mechanisms of various processes in the Earth’s interior.

Considering the interplay of metamorphic reaction and mechanical properties in our quantification approaches is critical for correct interpretation of observations in metamorphic rocks. In my contribution, I will show major applications of the new quantification approaches, the accompanying obstacles and the consequences for our petrological interpretations. New findings from coupled experimental and numerical studies emphasize the necessity of quantifying the stress/pressure distribution before any complex thermodynamic interpretations. In fact, any thermodynamic interpretation of a stressed system must take into account the locally-resolved state of stress during sample deformation.

The grain-scale mechanisms of hydration of mafic lower crustal rocks are investigated on chemical maps of continuous rock sections (20 x 2 cm) of partially amphibolitized samples from the Hustad Igneous Complex in the Western Gneiss Region, Norway. The Proterozoic pyroxenite body and crosscutting dolerite dike enclosed in felsic gneiss that underwent (U)-HP metamorphism show different responses to the exposure to hydrous fluids along fractures formed during late Caledonian extension and exhumation. While the dolerite reaches full amphibolitization in a cm-scale reaction halo with a dm-scale transition zone, the pyroxenite has experienced previous metamorphism and is less affected by this event. Dissolution-precipitation reactions and slightly faster grain boundary assisted flow are identified as the main mechanisms of fluid flow through the rock. Limited element mobility is documented by grain-scale compositional gradients in forming amphibole from magnesiohornblende (Si_6.8, Al_1.6, Mg_3.0) to tschermakite (Si_6.4, Al_2.0, Mg_2.6) at boundaries with plagioclase. Phase diagram calculations yield a P/T-window between 650 – 730°C and 0.4 – 0.6 GPa for amphibolite formation. To better understand the mechanism of hydration, a numerical model of Darcy flow coupled to amphibolitization reactions was formulated based on mass conservation and local equilibrium. The simulations suggest the observed difference in front propagation distance is controlled by the main lithologies. A simple 2D model is employed to demonstrate that the gradual transition from dolerite to amphibolite can be achieved by implementing higher permeability along grain boundaries, supported by the observation that flow along boundaries continues before individual grains are fully replaced.

In the Southern Brasília Orogen (south-eastern Brazil), a nappe system that represents the roots of a magmatic arc records HT-UHT metamorphic conditions in lower to mid-crustal rocks. It is divided into two segments by a major shear zone, of which the northern nappe hosts the most extreme metamorphism and has been targeted for most petrochronological studies. These rocks carry insights into the stages of orogeny, as well as the first direct evidence of the paleo-active margin basement, and time-constraint (1) a metamorphism related to the magmatic arc consolidation on the active margin at 670-640 Ma and (2) an enduring UHT event related to collision and decompression at 630-590 Ma. The southern nappe (Socorro Nappe) hosts felsic and mafic granulites, and migmatites that apparently describe a less extreme pressure-temperature setting and relatively younger ages. We found distinctive patterns pertaining the inner nappe and its outward boundaries (Embu Terrane and São Roque Domain). We present new U-Th-Pb_C monazite data and LA-ICPMS U-Pb and Lu-Hf systematics in zircon retrieved from granulites, migmatites and paragneisses, and partial results on conventional thermobarometry and thermodynamic modelling. Our data plot within the P-T range of upper amphibolite to granulite facies and describe mostly post-peak retrograde clockwise trajectories, with lesser conditions at the nappe boundaries. Temperature, textural context and anatexis are major controls on the preservation of monazite versus zircon records. The outer nappe tends to host prominent 750 Ma-old monazite, whereas in the inner nappe such ages are scarce and most prevalent in the zircon records.

To meet the global commitments for net zero carbon emissions our energy mix must transition from fossil fuels. Hydrogen is gaining increasing recognition as a low carbon energy option to support this energy transition. Hydrogen is considered a low-carbon substitute for fossil fuels to decarbonise domestic and industrial heat, power generation and heavy-duty transport. It can also promote increased renewable energy uptake by acting as an energy store to balance supply and demand.

For hydrogen to be deployed at the scales required for net zero, we will need access to large-scale geological storage. This talk will present an overview of the most recent findings from research working to establish the feasibility of storing hydrogen in underground porous reservoirs. The talk will cover the results of research into the key biological and chemical reactions between the reservoir rocks, formation fluids and injected hydrogen that could compromise the storage complex and the key flow processes that influence hydrogen migration and trapping during injection and withdrawal. It will also consider the role of hydrogen storage within an integrated energy system.

The first Hydrogen storage caverns of Germany are planned to be constructed at the salt cavern field Epe in NRW, where 114 caverns, of which more than 50 are currently used for natural gas storage, are located. Since gas filled caverns experience convergence over time and thus cause subsidence at the surface, it is important to have a monitoring concept with high spatial and temporal resolution, to predict future subsidence and potential damage to infrastructure, but also to detect unexpected subsidence quickly and assist in identifying the cause.

Epe displays a complex surface deformation field, consisting of cavern convergence caused linear trends, as well as precipitation dependent seasonal and cavern pressure dependent contributions as shown in previous studies of the area.

As part of the SAMUH2-Project, funded by the German Federal Ministry of Economics and Climate Protection, we are working on a monitoring concept to incorporate the already established methods of yearly levelling and GNSS measurements into our approach of using Interferometric SAR (InSAR) time series, which provide not only high spatial, but also good temporal resolution. Here, we use Sentinel-1 SAR data from 2015 to 2022, and process time series by using a joint approach of persistent scatterer (PS) and distributed scatterer (DS) techniques.

Our results show good agreement of the InSAR time series with other geodetic measuring methods. We can distinguish the signals of the different source mechanisms well and can even model varying cavern convergence rates, depending on the extent of the yearly cavern depletion and filling.

In the current global race towards achieving self-sufficiency and sustainability in meeting energy demands with net-zero emissions, hydrogen has emerged as a promising solution. However, hydrogen's volumetric energy density is lower compared to conventional energy sources, and the storage conditions (pressure and temperature) for hydrogen on the surface are expensive and technically challenging.

To overcome the challenge of large-scale hydrogen storage, researchers around the world have proposed storing hydrogen in subsurface geological structures, such as salt caverns and porous reservoir rocks. While hydrogen storage in salt caverns is a more advanced concept, storing hydrogen in porous rocks such as depleted reservoirs and aquifers requires further research attention. This paper outlines a preliminary workflow for a feasibility study on the use of depleted gas reservoirs for hydrogen storage. Two different fields in Germany are used as examples to illustrate the process. One of the case study fields is still producing from the carbonates of the Zechstein Group, while the other is a decommissioned field that previously produced from unconsolidated Neogene sands. The workflow involves creating a static geological model and populating it with petrophysical parameters, followed by dynamic flow simulation for history matching. Hydrodynamical parameters for hydrogen are then introduced to simulate hypothetical storage cycles. A geomechanical model is then created incorporating the pore pressure data and material properties, to assess storage integrity, fault activity, and surface deflection in response to hydrogen filling. Overall, this workflow provides a comprehensive approach to evaluate the potential for hydrogen storage in depleted reservoirs.

In the frame of the SAMUH2 project water samples were taken at a geological pore gas storage. In the course of the abandonment of a natural gas storage, deep fluids could be recovered from a depth of 500 - 600 meters. A total of eight boreholes were sampled from injection and observation wells. The focus of the investigations was on the analysis of the chemical composition of the fluids as well as the characterization of the microbial biocoenosis and partly also their metabolic activity.

Organic acids were detected in varying concentrations and compositions in both the fluid samples taken at the injection and observation wells. Organic acid concentrations ranged from 0.1 to 730 mg/L. Gen copies of Bacteria, sulfate reducers (SRB) and methanogenic archaea were detected in all fluids by qPCR. A detailed characterization of the microbial community was carried out by microbiome analysis. A diverse microbial community was detected on fermenters and methanogenic archea. Sulfate reducers, on the other hand, were identified predominantly in the observation wells.

Several laboratory experiments demonstrated that the fluids of injection wells contained an active biocenosis capable of hydrogenotrophic methanogenesis. In contrast, only one observation well fluid demonstrated the activity of hydrogenotrophic methanogenic archaea. The capability of underground storage facilities for producing eco- ("green") methane is a further topic of this study.

Underground H₂ storage (UHS) in salt caverns, deep saline formations, and depleted oil/gas reservoirs has emerged as a reliable and safe technology for storing renewable energy and reducing carbon dioxide emissions. H₂ gas, however, is one of the most important electron donors for many subsurface microorganisms. During the multiple cycles of H₂ injection and withdrawal operations, a certain amount of H₂ is permanently lost due to various physical, chemical, and biological mechanisms. Although research in UHS in porous media is evolving, our understanding of the impacts of cyclic loading and microbial activity on H₂ recovery and loss mechanisms remains inadequate.

In this study, we present recent findings from a quantitative investigation of H₂ reconnection and recovery mechanisms in repeated injection-withdrawal cycles using a microfluidic pore network simulating shallow reservoir storage conditions (30 barg). Our results reveal that H₂ storage capacities increase with higher injection rates, ranging between approximately 10% and 60%. Additionally, we observed the growth of a typical halophilic sulfate-reducing bacterium in the hydrogen-saturated pore network for 9 days. Significant H₂ loss occurred due to microbial consumption within 2 days following injection into the microfluidic device. These results may have significant implications for hydrogen recovery and gas injectivity. Microvisual experiments provide critical observations of bubble-liquid interfacial area and reaction rate that are essential to the modeling that is needed to make long-term predictions. Our results contribute to improving the selection criteria for future storage sites, ensuring optimized and efficient H₂ storage and utilization.

The Andean region possess a wealth of mineral resources, such as copper and lithium, which are increasingly in demand by various industries and sectors, including renewable energy, electronics, and transportation. The mining industry has the potential to contribute significantly to its growth and social development, desirably in line with the Sustainable Development Goals (SDGs) of the UN Agenda 2030. At the same time, the sector also creates complex socio-economic and environmental challenges in the region.
In this context, the German Federal Ministry for Economic Cooperation and Development (BMZ) has commissioned the Federal Institute for Geoscience and Natural Resources (BGR) to carry out the MinSus project in cooperation with its regional counterpart, the United Nations Economic Commission for Latin America and the Caribbean (ECLAC).
The presentation will showcase how the MinSus project has promoted responsible and sustainable mining in the Andean countries over the past seven years, highlighting how the project has worked through building capacity for sustainable mining practices, improving governance frameworks, and fostering partnerships between stakeholders.
The presentation will also feature examples of dealing with abandoned mining sites. It will be illustrated how the investigation of these sites with regard to environmental and health hazards can be carried out, as well as how the potential for tailings reprocessing can be determined (“secondary mining”), demonstrating concrete approaches and applied geoscientific methodologies to managing mining legacies in a responsible and sustainable way.

For 60 years, Germany’s National Metrology Institute Physikalisch-Technische Bundesanstalt (PTB) has been promoting the improvement of metrology systems and quality infrastructure within its partner countries in the Global South. Metrology and quality infrastructure are fundamental for the reliable measurement of all environmental parameters. Thus, geoscientific research heavily relies on them as a basis for comparable and accurate data.

Quality infrastructure includes metrology, standardization, testing, quality management, certification, and accreditation. PTB endeavours to strengthen all these components in its technical cooperation projects. For example, PTB works with its partner institutions in the Global South on the adaptation and development of environmental standards. These include, among others, standards concerning soil and water quality. Furthermore, PTB supports the process of accreditation of analytical test laboratories to increase credibility of environmental data on water, air, and soil.
All environmental data relies on the conformity of units. Accredited laboratories need to proof the traceability of their measurements up to the highest metrological authorities. PTB therefore strengthens National Metrology Institutes in its partner countries with regards to environmental services.

In the presentation, the components of quality infrastructure and their importance for geosciences will be introduced. Highlights from PTB projects in India and Guatemala will showcase success stories of improved quality infrastructure in the context of international cooperation for geoscientific applications.

Mongolia is a sparsely populated, resource-rich country with a wide range of different mineral deposits and mining activities in size and quality of operation, distributed over a vast area of the territory. The wealth of mineral resources already being mined or developed for future exploitation, provide the country with a huge opportunity for its economic progress but also present challenges for a sustainable and effective state management of the mining sector.

Since the political change in Germany and Mongolia in the 1990s, the BGR (Federal Institute for Geosciences and Natural Resources) has carried out various projects within the framework of the German-Mongolian development cooperation, together with different Mongolian government institutions responsible for the mineral resources sector. To support a transparent and efficient governance of a responsible and sustainable mining sector, the BGR-projects focused mainly on capacity development and elaboration of professional information and data at the geology and mining authorities. In recent years, the focus has been increasingly on supporting digital transformation processes in connection with more efficient mining inspection and supervision works, digital mining cadastre, the digital management of geological maps, as well as enhancing the digital data exchange between institutions. These digital instruments support a more transparent and efficient state management of the mining sector and, during the Covid-pandemic, enabled the continuation of administrative processes (licensing, permits, reporting). Yet, the continuous need for further refinement and maintenance of these digital systems presents a challenge for human and financial capacities of state authorities in developing countries

Honduras, located in Central America at the convergence of the North American tectonic plate with the Caribbean plate in the northwestern part and the Cocos plate with the Caribbean plate in the southern part, has geothermal potential not only related to power production but also for direct use application. A special strategic approach in the Central America is the geoscientific exploration of the over 1500 hot springs in the region. Only in Honduras, there are over 200 hot springs identified, from which over 40% have a superficial temperature of over 50°C and over 10% have temperatures of even more then 80°C.

This abstract presents the case of geochemical investigation in in Namasigüe and El Triunfo districts, located near the border to Nicaragua, in order to proceed in the identification of a deep geothermal reservoir but also identify the opportunity to delineate the potential of geothermal direct use for the community. Important elements of the geoscientific exploration in this socially conflictive area is the preparation of geoscientific information to raise awareness regarding the thermal waters among the local community but also to enhance the acceptance for the geothermal exploration taken out by the National Electric Power Company (ENEE).

The activities are part of Yacimientos II project, implemented by the Federal Institute for Geosciences and Natural Resources (BGR) from Germany and are supported by the National Secretary of Energy (SEN), who has an operative involvement with local communication concepts to prepare geoscientific findings for the community.

BGR and the Zambian government jointly develop and protect the groundwater resources in the country’s capital Lusaka. As one of the fastest growing cities in southern Africa, Lusaka has been facing a sharp increase in the demand for water in recent years.

Sustainable abstraction of groundwater and the protection of the vulnerable karst aquifer supplying Lusaka are two key elements for future urban planning in the face of population growth, annual outbreaks of waterborne diseases and climate change. Geoscientific experts have to ensure that decisions are based on scientific results and technical recommendations and that the importance of protecting the natural resource is being communicated as a priority to the government, industries and society.

Potential new well fields were identified and one objective of the BGR project is the delineation of groundwater protection zones as a case study for Zambia. The development of statutory instruments to make groundwater protection an integral part of the Zambian law secures the resources for the future. The delineation of the zones is based on the approach from Botswana, as the various Western approaches cannot simply be transferred to southern Africa as soil structure, geology, climate and urban areas are often drastically different.

Protecting a karst aquifer with a thin soil cover is scientifically challenging. The population growth and limited urban planning structures combined with insufficient data increase the risk of groundwater contamination in Lusaka. A high level of cooperation between geoscientists, decision-makers, environmental regulators and the society is required to face the various challenges.

Analytical challenges such as low concentrations and a saline matrix, contamination risks during sampling and analysis, and the accessibility of remote ocean areas limit available methodologies for the investigation of trace elements in the open ocean and call for innovative, easy to use and robust investigation tools. Furthermore, the application of methodologies for the monitoring of e.g., deep-sea mining activities as part of environmental impact assessments will become of increasing importance for future marine research. We here evaluate an in situ passive sampling method using the technique of diffusive gradients in thin films (DGT), focussing on Mn, Cu, Ni, V, Cd, As, Sb, and rare earth elements and yttrium. Sampling was performed in bottom seawater above the BGR contract area for polymetallic nodule exploration in the Clarion Clipperton Zone in the NE Pacific. We present data from different passive sampling setups at depths between 0.3 m and 550 m above the seafloor accumulating trace metals for periods of 3 days up to 2 years, and discuss the effects of deployment time and the binding membrane type. Derived concentrations represent the labile fraction of the metals and hence that fraction that is (bio)available for an uptake through cell membranes. Results are compared to point sampling of seawater providing trace metal concentrations for different size fractions, which allows to constrain the degree of lability of dissolved trace metals. We further present results from the monitoring of a collector mining test of polymetallic nodules with respect to trace metal mobilization at the seafloor.

Thirty years ago, scientists from the Technical University of Denmark and University of Bergen published 3D outcrop acquisition and processing methods for large-scale vertical cliff sections in Greenland (Dueholm & Olsen, 1993), thus laying out a pathway to today’s state-of-the-art in high resolution virtual outcrop modelling. Although the photogrammetric methods employed were based on film cameras and early digital processing, the authors successfully created stereoscopic outcrop models that could be used for accurate measurement of cross sections, channel bodies, and derived parameters such as net-to-gross ratio. Fast forward to today, and virtual outcrop modelling has evolved rapidly, spanning early work using laser scanning, integration with hyperspectral imaging, and the full-circle return to photogrammetry. The latter has brought about a paradigm shift in field geoscience, driven by lightweight digital cameras, drone platforms, and powerful computing hardware combined with automated image matching and point cloud generation algorithms. This has empowered geologists and geoscientists to quickly – and at low cost – acquire and process high resolution, accurate 3D models for detailed analysis. Over the last five years, and particularly through the COVID-19 pandemic, virtual outcrop models have been increasingly used for “soft” purposes, in education and training, for introducing a wide range of different geological features and concepts that may be difficult to access in a single field area, or as the basis for integrating a range of geospatial, field and subsurface data. In this contribution we will explore the status and impact of virtual outcrops and offer thoughts on future perspectives.

Virtual and mixed reality technologies are reaching maturity for both professional and consumer applications, offering not only stereoscopic 3D visualization environments but also novel user interfaces with more immersive experiences of interacting with 3D content. Geosciences, which inherently deal with 3D complexities, can greatly benefit from these advancements. However, the potential benefits remain largely untapped for professional applications. Recent developments are bringing 3D geodata visualization with collaboration into virtual spaces. Nonetheless, the actual steps of 3D geological model creation and modification remain predominantly limited to workstation computers and 2D displays.

Addressing these limitations, we present LiquidEarth, a software solution that integrates rapid geomodeling with immersive mixed-reality environments. Utilizing a cloud-accelerated implicit modeling algorithm, LiquidEarth offers a dynamic experience of creating and updating 3D geological models in virtual spaces with real-time feedback. Cross-platform compatibility makes the solution device-agnostic, facilitating adoption in various geoscience applications and scenarios, including fieldwork.

The software combines features such as immersive visualization, real-time collaboration, field connectivity, workflow connectors, and flexible export options to create an integrated and versatile tool, making it ideal for geoscientific work in industry, research, and education. This holistic approach bridges the gap between immersive visualization of geological data and geological modeling, enabling geoscientists to harness the full potential of mixed reality technologies.

LiquidEarth signifies a substantial, yet initial, step towards the future of geomodeling by transcending traditional constraints. Its objective is to augment the geoscientific expert's ability to analyze and comprehend intricate geological 3D complexities while promoting the development of insightful conclusions.

The geometry of carbonate systems reflects the interaction of several factors. Although efforts have been made at investigating the controls on biogenic carbonate system evolution, the impact of the interaction of different carbonate producing biotas is still not fully understood. In this study, we developed a 4D stratigraphic forward models (SFM) of the Miocene Llucmajor platform coupled with sensitivity analysis to examine the effect on platform geometry of changes of the dominant biotic production in the oligophotic and euphotic zones. Our results indicate that the geometry of the platform is impacted by a complex interaction between carbonate production rates, variations in bathymetry, and changes in accommodation. Progradation in the platform model is mainly controlled by oligophotic production of rhodalgal sediments during the lowstands. This study also shows that platform geometry and internal architecture is significantly impacted by the interaction of the predominant carbonate producing biotas. The input parameters for this study are based on well-understood Miocene carbonate biotas with characteristic euphotic, oligophotic and photo-independent carbonate production in which it is essential to explicitly model each carbonate producing class within the simulation run and not averaged with a single carbonate production-depth profile. This distinction is particularly crucial for subsurface exploration studies that rely on stratigraphic forward models, where the overall platform geometry may be approximated through calibration runs and constrained by seismic surveys and wellbores. However, the internal architecture could be over-simplified, without an in-depth understanding of the target carbonate system such as is provided by this study.

Digitalisation helps to improve planning, make processes more transparent, save resources and counteract the staff shortages that will become even greater in the future.

BAUER Resources GmbH has been using the BIM methodology for over a decade, and for some years now processes in construction site operations and planning have been digitally supported.

With the help of drones, apps on mobile devices and sensors, linked with intelligent systems, execution and planning are being taken to a new level of detail, transparency and speed.

The detailed planning and execution of geothermal projects including geologie and hydrologie with digital support will be presented. Implementations in BIM with automation and other digital techniques (including real-time data from the construction site) which leads to a digital twin will be presented.

The diversification of marine reptiles played a major part in the Triassic Revolution and represented the first large-scale return of tetrapods to an aquatic environment. Recently, a new marine archosauromorph clade, Dinocephalosauridae, was recognised, considerably increasing the known diversity of Triassic marine reptiles, particularly among the generally terrestrial Archosauromorpha. Its best-known member, Dinocephalosaurus orientalis, superficially resembles plesiosaurs, possessing a hyperelongate neck composed of many cervical vertebrae, an elongate torso, and flipper-like limbs. The osteology of Dinocephalosaurus is virtually completely described based on newly discovered specimens. Up to six metres long, it is characterised by its long tail and even longer neck. The appendicular skeleton exhibits a high degree of skeletal paedomorphosis recalling that of many sauropterygians, but the skull and neck are completely inconsistent with sauropterygian affinities. Its cranial morphology, including the presence of narial fossae, is very similar to that seen in another long-necked archosauromorph, Tanystropheus hydroides, which largely represents a convergence related to an aquatic piscivorous lifestyle. Chinese discoveries such as Dinocephalosaurus merit a re-evaluation of historical European collections. Based on such a revision, we also redescribe Trachelosaurus fischeri, known from a single, disarticulated specimen collected in the 1800s from the Solling Formation (Buntsandstein) of Bernburg, Germany. It possesses short, bifurcating cervical ribs, which are unique among archosauromorphs. Trachelosaurus is confidently recognised as the first European dinocephalosaurid based on a wide range of character states, including its highly presacral vertebral count, wide dorsal transverse processes, holocephalous dorsal ribs, an ilium lacking a preacetabular process, and a rod-like femur.

Sauropterygia was a taxonomically and ecomorphologically diverse clade of Mesozoic marine reptiles spanning the Early Triassic to the Late Cretaceous. Sauropterygians are traditionally divided into two groups representing two markedly different body plans – the short-necked, durophagous Placodontia and the long-necked Eosauropterygia – whereas Saurosphargidae, a small clade of armoured marine reptiles, is considered as the sauropterygian sister-group. However, the early evolutionary history of sauropterygians and their phylogenetic relationships with other groups within Diapsida are still incompletely understood. Here, we report a new saurosphargid from the Early Triassic of South China, representing the earliest known occurrence of the clade. An updated phylogenetic analysis focussing on the interrelationships within diapsid reptiles recovers saurosphargids as nested within sauropterygians, forming a clade with eosauropterygians to the exclusion of placodonts. Furthermore, a clade comprising Eusaurosphargis and Palatodonta is recovered as the sauropterygian sister-group. The phylogenetic position of several Early and Middle Triassic sauropterygians of previously uncertain phylogenetic affinity, such as Atopodentatus, Hanosaurus, Majiashanosaurus and Corosaurus, is also clarified, elucidating the early evolutionary assembly of the sauropterygian body plan. Finally, our phylogenetic analysis recovers Testudinata and Archosauromorpha within Archelosauria, a result strongly supported by molecular data, but until now rarely recovered by any phylogenetic analysis using a morphology-only data set. Our study provides evidence for the rapid diversification of sauropterygians in the aftermath of the Permo-Triassic mass extinction event and emphasises the importance of broad taxonomic sampling in reconstructing phylogenetic relationships among extinct taxa.

The histology of bone can be preserved virtually unaltered for hundreds of millions of years in fossils from all environments and all vertebrate taxa, giving rise to the flourishing field of paleohistology. The shafts of long bones are formed by the apposition of periosteal bone tissue, similar to the growth of wood, and preserve (an often cyclical) record of the growth of the individual and events in its life history. One such event is sexual maturation or puberty, during which hormonal changes transform the juvenile into a sexually mature adult. Puberty has been well studied in humans and some other living vertebrates. Here we describe puberty in Keichousaurus, a small sexually dimorphic and live-bearing marine reptile from Middle Triassic rocks of SW China, about 240 million years old. Using a combination of bone histology and morphology, we detected puberty as one of four life stages (the others being foetus, juvenile, and adult). Adult Keichousaurus males have a more robust humerus than females with pronounced muscle attachment sites and a triangular shaft cross section. Mid-shaft sections of the humeri of the males show the transition from the rounded juvenile cross section to the triangular adult cross section, as reflected in the contour of the growth marks. This shape change is produced by differential bone apposition of the periosteum, presumably triggered by sex hormones, as in humans, and influenced by changes in loading regime during puberty. This is the first report of puberty in a fossil amniote.

The end-Triassic Extinction Event (ETE) lead to the demise of ~76% of species, as well as major biotic transitions in terrestrial vertebrate faunas. These include the shift from a mainly synapsid- and pseudosuchian-dominated ecosystem in the Triassic (e.g. dicynodont and cynodont therapsids) to dinosaur-dominated ecosystem in the Jurassic. Our understanding of this crucial time in Earth’s history is hindered by the lack of sedimentary deposits that record the Triassic–Jurassic boundary and bear informative vertebrate fossils across this interval. Several southern African basins are infilled by uninterrupted Carnian–Pliensbachian sediments. These include the Stormberg Group of the main Karoo Basin of southern Africa, as well as the Mid-Zambezi and Tuli basins of Zimbabwe. Surprisingly, the paucity of the current known fossil record recovered from these southern African deposits limits their use in understanding the ETE. This is in part because, to date, the Late Triassic vertebrates known to pertain from these units are much less abundant and diverse than those from the Early Jurassic units. Over the last decade, increased field work targeting these areas, combining excavations with high-resolution dating and biostratigraphy, has yielded multiple new fossil-bearing localities that add crucial new data to our understanding of ETE faunal change. Here, I present an overview of these novel sites. One notable location includes the late Norian quarries from near the village of Qhemegha in the Eastern Cape of South Africa which preserve a diversity of vertebrates such as: large-bodied late-branching pseudosuchians; large- and small-bodied sauropodomorphs and theropods; non-dinosaurian avemetatarsalians; and synapsids.

Der Braunkohleausstieg führt zu Veränderungen in allen Bereichen der Wasserwirtschaft. Im Rheinischen Revier werden sich nach dem Ende des Bergbaus einige der größten deutschen Seen bilden. Der Grundwasserspiegel steigt und die Fließrichtung des Grundwassers ändert sich. Einige Oberflächengewässer führen mehr Wasser, andere weniger. Wasser wird ein wichtiger Faktor in der gesamten Region sein, aber es wird auch einen Wettbewerb um Wasser auf lokaler Ebene geben. Die Veränderungen in der Wasserwirtschaft sind wesentliche Randbedingungen im Strukturwandel im Bergbaugebiet.

Im Rheinischen Revier verursachten die Entwässerungsmaßnahmen rund um die Tagebaue ein Defizit von mehr als 20 Milliarden Kubikmetern Wasser. Beim Ausgleich dieses Defizits spielt die Nutzung von Wasser aus dem Rhein, das durch große Wasserleitungen gepumpt wird, eine wichtige Rolle. Die Befüllung der Seen wird etwa 40 Jahre dauern. Die Auswirkungen des Klimawandels werden in diese Planung einbezogen.

Eine der Kernaufgaben im Rahmen des Braunkohleausstiegs ist die Sicherstellung der Trinkwasserversorgung. Der Zufluss von Grundwasser aus den Abraumdeponien, das aufgrund von Pyritoxidationseffekten etwa 1.500 mg/l Sulfat enthält, wird die Schließung von mindestens vier Wasserwerken erzwingen. Darüber hinaus werden ca. 12 Wasserwerke von infiltriertem Rheinwasser betroffen sein, das verschiedene organische Spurenstoffe enthält. Ein flächendeckendes Wasserversorgungskonzept wird die Trinkwasserversorgung von mehr als 2,5 Millionen Einwohnern sicherstellen.

The largest contiguous former opencast lignite mining district in the EU is located in Lusatia (Germany). Hydrochemical contaminations such as acid mine drainage from opencast mines as well as increased susceptibility to soil instabilities pose major challenges for the reclamation of the Lusatian mining district in the coming decades. Therefore, time- and cost-efficient methods investigating former opencast lignite mines are vital for a sustainable remediation and reclamation.

In Lusatia, loose Cenozoic sediments (sands, silts, clays, and glacial tills) form several tens of metres of heterogeneous lithological successions in extensive opencast dumps. However, the effects of newly formed depositional structures, spatial heterogeneities and pore water mineralisation of the opencast dumps on groundwater flow and mass transport remain largely unknown in the post-mining areas of Lusatia.

In this study, we developed a workflow that makes use of spatially variable and heterogeneous input data ranging from airborne geophysics, geological maps and drilling logs. In a first step, we created 3D-representations of an exemplary post-mining area in Lusatia by using both classical geological interpretations as well as machine learning approaches. In a second step, the 3D representations are compared to each other and are used as input data for numerical groundwater modelling in order to analyse the effect on the simulated groundwater flow. This approach allows us to optimise the 3D-modelling workflow and to refine our understanding of the flow and mass transport processes between groundwater and pit lakes in the subsurface of post-mining areas.

As a result of the rearrangement of tertiary sediments and the groundwater lowering during open pit lignite mining, the formerly stable iron sulfide compounds oxidize to iron and sulfate ions and acidity. With the end of mining operations and the resulting rise in groundwater levels, these substances are transported into surface water, causing negative effects on the ecosystem and water management.
Sulfate reduction reverses the preceding oxidation process. By adding a carbon source, sulfate-reducing bacteria are activated in the aquifer. These metabolize the added carbon, producing sulfide which combines with the iron present in the groundwater to form iron sulfide and is fixed in the subsurface.
The process has already been tested as a pilot project in the Lusatian coalfield. For the transfer to the Central German mining district, adjustments had to be made to the plant design due to the cohesive soils and higher concentrations of iron and sulfate.
The plant configuration provides for a modular structure consisting of six self-sufficient sections. In each module, 86 individually controllable lances are provided for both lifting and infiltration of the water. Infiltration takes place in one lance at a time, while water is being lifted from other lances or these are paused so that water flows in. In this way, the problem of groundwater surface drawdown caused by upstream wells or the disadvantages of using external water are avoided. The lifted water is mixed with glycerine as a carbon source and then infiltrated again.

Empirical trophic models (Vollenweider-type) are one of the basic "tools of the trade" in management of natural and artificial lakes. They are not applicable to open-cast mining lakes (PML) because they underestimate their resilience to phosphorus (P) inputs. The high iron availability causes an efficient binding for phosphorus (P) in water and sediment of PML. The main objective was use hydrogeochemical modelling to assess the risks of eutrophication in the following way:

i) to develop conceptual (empirical) models (Vollenweider type) that can be used to more accurately estimate tolerable P loading to PMLs

ii) to represent the transition range from conditions with Fe excess to natural conditions in a model structure

iii) to identify specific indicators and tipping points for different P retention.

We analysed hydrological data, loads, and sediment properties to derive a closed P balance for 29 neutral mining lakes. The latter cover a range of water retention times and external P inputs. We distinguished three phases of PML development or maturation and the relevance of P-binding processes or binding forms. The Fe:P ratio in sediment was found to be the most important predictor of P retention. By integrating this ratio into conceptual models it is now possible to predict in-lake P-concentration from P inputs for PMLs and even for lakes with decreasing Fe import at the transition to “natural lake” conditions. We conclude that processes such as Fe~P adsorption and vivianite formation under anoxic conditions most likely ensure high P retention in the long term.

Lake Runstedt (near Merseburg, Germany; area 2.3 km², volume 53x10⁶ m³, max. depth 32.8 m) is an artificial lake resulting from lignite mining. The lower part of the former mine void was filled by industrial wastes consisting mainly of ashes but also containing waste from nitrogen fertilizer production rich in ammonium. Ammonium concentrations exceed 300 mgL^-1 in the pore water in the deposited wastes and constitute a threat for the regional groundwater resources. For protecting the groundwater, Lake Runstedt was created by filling the remaining space of the mine void above the waste with water from Saale River. The neighbouring pit lakes are managed in a way that groundwater flows into Lake Runstedt from all directions and that there is no outflow except evaporation. Hypolimnetic aerators provide the hypolimnion with oxygen needed for nitrification and reed was established in the littoral as habitat for denitrification. Since completion of the filling in 2003, the system has worked well as documented by monitoring. Usually, limnologists look at lakes as valuable ecosystems that have to be protected. In case of Lake Runstedt, the lake is used as a reactor. This unusual approach should not be a common preference but considered as exceptional option in applied limnology. The presentation will report on the creation of Lake Runstedt, the results of monitoring and research, and discuss the use of lakes as reactors protecting other compartments of the environment.

For more than a decade, re3data (https://www.re3data.org/), the global registry of research data repositories, has helped researchers, funding agencies, libraries, and other research data services to find, identify, and reference research data repositories. As the world's largest directory of data repositories, re3data describes over 3100 infrastructures on the basis of its comprehensive metadata schema in May 2023. The service allows searching for research data repositories of any type and from all disciplines, and users can filter results based on a wide range of characteristics. The re3data descriptions are openly accessible via an API and are reused by numerous open science services, including DataCite Commons. re3data is engaged in various initiatives and projects concerning data management and is mentioned in the policies of scientific institutions, funding organizations, and publishers.

The presentation will focus on the growth, development, and accomplishments of re3data over more than 10 years that have resulted in re3data becoming the most comprehensive information and metadata resource on research data repositories. Further, the presentation will address how re3data’s activities can support the establishment of best practices, support open science, and facilitate networking within different research communities. With over 850 entries the field of geosciences is one of the most strongly represented subject groups in the registry.

LI@Geo.X is a search portal for the laboratory infrastructure in the Geo.X network, jointly developed by the network partners. It supports collaborations and joint projects by providing information on instruments, analytical methods, contact persons, location of the laboratories, and links to their websites. LI@Geo.X is undergoing further development as LabInfrastructure@Geo.X in the framework of the Helmholtz DataHub Initiative. We extend the metadata scheme by adding, e.g., access information to the laboratories, user regulations, key and data publications. As technical improvements we implement:

• a web-based user interface (change request form) for submitting new or modified laboratory metadata. This change request form is also equipped with a vocabulary tool for keywording instruments and analytical methods. For this we use the controlled vocabularies of the NASA GCMD instrument keywords and a vocabulary adapted for the Geo.X network.
• a management interface which facilitates the decentralised editing and maintenance of the laboratory metadata.
• semantic search options and filter functions which are aligned with the needs of the scientific target groups.

Including over 220 entries, LabInfrastructure@Geo.X cooperates with various Helmholtz initiatives and is embedded into the NFDI4Earth landscape.

The BGR GeoPortal is a comprehensive platform that facilitates seamless access to geoscientific data, fostering data exploration and integration. In this abstract, we highlight several key features of the GeoPortal and discuss our ongoing efforts to address challenges in consolidating data sources and promoting data sharing.

To enhance the integration of geoscientific data with existing literature, the GeoPortal incorporates a linkage to the Geological Literature Linked Data (ZSN). This integration allows users to seamlessly connect relevant scientific publications with associated geospatial data, promoting a more holistic understanding of geological phenomena.

The inclusion of an RDF interface within the GeoPortal further supports data integration and interlinking. By providing a standard semantic web interface, the GeoPortal enables users to connect and exchange data with other systems, fostering a networked environment for collaborative research and data sharing.

METAVER (https://metaver.de/) is the central platform for recording and publishing (INSPIRE) geospatial metadata from various federal states of Germany. It offers various interfaces for recording and further processing metadata. An editor tailored to the requirements in the institutional area supports standard-compliant recording, according to various aspects of metadata rules in Germany. A web application enables comfortable research and visualization of data sources and providing services. METAVER was implemented with the INGRID software, which is being developed as part of an administrative cooperation of all federal states of Germany.
In the state of Brandenburg, and here specifically in the environmental sector, various requirements are covered by the application. The requirements result, for example, from the Environmental Information Act, the INSPIRE Directive and the OpenData Act.
The talk describes the framework conditions of the application and its basic structure and discusses the synergy effects of the application throughout the METAVER partners.. It also describes the integration of data interfaces of the state of Brandenburg and their integration into processes such as the Opendata strategy and provision of metadata according to the INSPIRE Directive.

For more than a decade, there is an increasing international demand for free and open access to publicly funded scientific research products. These include “classical” text manuscripts, data and software underlying scholarly publications, raw and curated observational data, and many more. Essential for the long-term preservation and re-use of these scientific datasets is the storage in appropriate, ideally domain specific repositories, accompanied by comprehensive data description and sufficient metadata for data discovery. These should include a licence for data re-use and sharing. Scientific datasets should be published using citable Digital Object Identifier (DOI).

GFZ Data Services is a repository for research data and scientific software across the Earth System Sciences, hosted at GFZ. The curated data are archived, persistently accessible and published with DOI. They range from large dynamic datasets from global monitoring networks with real-time acquisition, to international services in geodesy and geophysics, to the full suite of small and highly heterogeneous datasets collected by individual researchers or small teams ("long-tail data"). In addition to the DOI registration and data archiving itself, GFZ Data Services team offers comprehensive consultation by domain scientists and IT specialists.

This presentation will introduce to the broad service portfolio of GFZ Data Services, including project-specific DOI landing pages for our national and international partners, data curation practices, supporting tools like the online metadata editor, data description templates and extensive data publication guidelines. It will further show examples of how metadata exchange with other data portals is increasing the visibility of our data publications.

The building and construction sector accounts for a significant proportion of current anthropogenic CO₂ emissions. Reducing the carbon footprint of building materials is difficult because some process-related CO₂ emissions cannot be avoided. While the industry is developing methods to reduce its emissions by capturing CO₂ from flue gas streams, this study investigates an alternative mechanism to reduce the carbon footprint of building materials, namely the incorporation of olivine into building materials such as façade plaster. Olivine is susceptible to weathering and reacts with CO₂ to form magnesium carbonate and silica.

In collaboration with the company Knauf Gips KG, an outdoor test facility will be built to monitor the mineralogical changes in olivine façade plaster under natural weathering conditions over a period of 18 months. In parallel, laboratory experiments will be carried out to accelerate the weathering process by continuous artificial weathering of the plaster samples. Fluids will be regularly sampled and analysed to detect potential environmental hazards, such as the release of nickel and chromium into the environment. All plaster samples will be analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to identify mineralogical and structural changes during the experiments. The extent of CO₂ mineralisation will be assessed based on mass balance calculations with the experimental reactants and their products. A sustainability assessment of the whole value chain will be carried out to determine whether olivine in building materials can effectively contribute to offsetting the CO₂ emissions of the construction industry.

Marine sediments may act as a sink for carbon. Substrate and electron donor availabilities, sedimentology, as well as biological activity may influence the carbon cycling, impacting the release of TA and DIC. The North Sea is a highly dynamic system with shallow tidal areas and fresh water tributaries delivering nutrients and dissolved carbon. For the southern part, benthic DIC sources have been identified [1], with tidal areas being further hot spots [2], some being impacted by submarine fresh water discharge [3]. The Skagerrak provides the unique opportunity of studying benthic DIC production under the impact of different dominant electron acceptors [4]. Potential transformation of carbonates may impact release of TA and DIC.

Here, we investigated the role of different sediments from the North Sea, including tidal areas, for their DIC source function and carbon storage capacity. Water column, pore water, and sediment samples were investigated to understand the processes controlling the benthic production and release of TA and DIC. The carbon isotope composition of dissolved and solid phases were investigated to understand the specific biogeochemical processes dominating benthic mineralization and carbonate dissolution.

[1] Burt et al. (2016) Limnol. Oceanogr. 61, 666-683. [2] Schwichtenberg et al. (2020) Biogeosciences, 17, 4223-4245. [3] Winde V. et al. (2014) J. Mar. Sys. 129, 394-402. [4] Canfield D.E. et al. (1993) Geochim Cosmochim Acta 57, 3867-2883.

The investigations are carried out within the BMBF project COOLSTYLE/CARBOSTORE. The Sylt part also contributes to the DFG project KiSNet, and investigations are further supported by Leibniz IOW.

The application of finely ground silicate minerals to croplands and forests, with the aim of enhancing the rate of natural CO₂ consuming weathering reactions, is receiving attention as a part of climate change mitigation strategies. Yet considerable uncertainty surrounds the quantification of CO₂ removal associated with Enhanced Weathering, and its potential efficacy remains undemonstrated outside of the laboratory. Here, I discuss how the geochemical insights garnered from decades of natural weathering studies provide a pathway towards a strategy for ‘Monitoring, Reporting and Verification’ of CO₂ sequestration. These natural weathering studies have also produced an understanding of what limits silicate weathering in different settings, which can be used to shed light on how deployment strategies, and specifically application sites, can be optimised.

Thermokarst lagoons form at the terrestrial-marine interface when thermokarst lakes, hotspots for Arctic methane emissions, erode onto the Arctic shelf. Thermokarst lagoons are dynamic environments with seasonal ice build-up and potential alternations between freshwater and marine discharge. Aiming to understand how microbial methane cycling changes along thermokarst lake to lagoon transitions we have investigated the sediment geochemistry and microbiota of the Polar Fox lagoon, a thermokarst lagoon in north-eastern Siberia, relative to that of two adjacent thermokarst lakes. In-situ methane concentrations, methane-carbon isotopic signatures, analysis of amplicon sequencing variants (ASVs), metagenomics, and pore-water geochemistry point towards efficient communities of anaerobic methane oxidizers (AOM) in a sulfate-methane transition zone 2-3 meters below the sediment surface of the lagoon. The lagoon’s in-situ methane concentration in the sulfate zone was only 0.4 – 5% that of the deeper sediment and of the two adjacent thermokarst lakes which have no connection to the Arctic Ocean. In the lakes, methane concentrations reached values up to 2.2 µmol per gram pointing towards oversaturation with methane in the sediment. Based on the analysis of general microbiome composition, we suggest that deterministic process triggered a substantial overall shift of microbial assemblages and a loss in spatial dissimilarity and diversity. Our study shows that thermokarst lake to lagoon transitions are associated with the formation of novel sediment microbiomes and that Arctic thermokarst lagoons can host efficient AOM communities with the potential to substantially mitigate methane concentrations in coastal thermokarst sediments.

Global warming is the greatest threat for humankind today. Despite all efforts to reduce CO₂ emissions, the undertaken measures are not sufficient to stop the temperature rise. One recently proposed and promising approach to actively remove CO₂ from the atmosphere is carbon dioxide removal through marine alkalinity enhancement. This technique increase the natural CO₂ uptake capacity of seawater through weathering of fine-grained alkaline minerals in marine environments. Even through this method has been extensively tested and verified by numerical models, field experiments scaling the CO₂ uptake under natural conditions and assessing the impact on the environment and biota are still lacking. To bridge this gap of knowledge a monitored 2-year in-situ experiment was established in September 2022 at the Ria Formosa Coastal Lagoon, southern Portugal.

The experiment was installed in the pioneer vegetation zone of the saltmarsh with three replicate plots. Each plot contain deployments of coarse olivine, fine olivine, coarse basalt and fine basalt and an unchanged area as control. Supernatant and porewater from each treatment are analysed monthly for temperature, salinity, oxygen concentration, pH, total alkalinity, nutrients, and trace metals. Sediment samples are analysed quarterly for faunal and floral composition to evaluate the impact on the biota.

The first months of the experiment showed an increase in total alkalinity in the supernatant and porewater of the treatments. Other environmental parameters remained stable among the different treatments and control. The total alkalinity decreased through time although remained on higher levels as compared to the natural background level.

Acknowledgment. Research supported by the Portuguese Science Foundation, with the projects PTDC/CTA-CLI/1065/2021, UID/00350/2020CIMA and contracts DL57/2016/CP1361/CT0009.

CO₂ neutrality by 2045 requires increasing the currently worldwide achieved CO₂ storage volume (40 Mt/y) to the order of tens of Gt/y. With current storage techniques, CO₂ often remains in the gaseous phase, thus, free to spread underground risking unwanted leakage in the distant future. As an alternative, the mineralization of CO₂ in basalts, where the vast majority (>90%) of the carbon is mineralized and fixed in carbonates within two years, offers a permanent safe storage as a solid (e.g. CarbFix, Iceland).
The international joint project PERBAS (ACT4) with partners from Norway, USA and India aims to pave the way for the commercialization of large-scale, permanent CO₂ sequestration into marine basalt complexes off the coast of Norway and India. The project seeks solutions for reservoir selection, CO₂ transport, injection and monitoring. PERBAS will investigate the feasibility of supercritical CO₂ injection, using water in the pore space, in order to avoid the requirement to inject 20 t of water for 1 t of CO₂. This would have the additional advantage that supercritical CO₂ would be associated with a free gas phase, which allows the application of geophysical remote sensing for monitoring thereby reducing the number of monitoring wells required.
Within the German sub-project CO2PR, geophysical field data (seismics and electromagnetics) will be collected during a research cruise offshore Norway currently planned for 2024. The resolution and efficiency of associated inversion techniques will be made usable for large-volume (Gt) reservoirs and complemented with new AI methods to identify signals suitable for monitoring.

Oman’s listwaenite formed when carbonate-rich fluids reacted with peridotite, reducing the atmosphere’s carbon. Listwaenite provides clues regarding natural global carbon flux and sequestration. Oman contains the world's largest exposure of oceanic lithosphere. Obduction of the peridotite-bearing Semail Ophiolite onto Arabia occurred during the Late Cretaceous. The ophiolite’s hot base exerted contact metamorphism onto tectonically underlying rocks (“metamorphic sole”). Post-obductional doming, extension and E/W-shortening overprinted the rocks. In the Fanja area, (par-)autochthonous platform rocks are in contact with allochthonous rocks, and numerous listwaenite bodies several kilometers long and tens of meters wide are exposed. Mapping of the Fanja area at the scale of 1:10,000, determined the listwaenite’s tectogenesis. Two models exist. Listwaenite formed either during Late Cretaceous convergence and subduction or during shallow post-obductional extension. Mapping confirms: (i) Two listwaenite generations exist: an early gently dipping and a more common late steeply dipping generation. (ii) Listwaenite contacts of both generations with the ambient rocks are always a non-contractional fault. (iii) The listwaenite-metamorphic sole contact of the older listwaenite bodies is discordant and faulted. (iv) Both listwaenite generations are typically tabular, while the metamorphic sole may be intensely folded. (v) Drag folds and Riedel faults indicate extensional and/or WNW-striking sinistral shear of the late listwaenite. (vi) The late-generation bodies cut different sections of the allochthonous. (vii) At the Fanja Half-Graben, listwaenite is in extensional fault contact with post-obductional sediments (uppermost Cretaceous Al-Khod Fm.). No listwaenite clasts are found within this formation. Our observations demonstrate that all listwaenite bodies formed during extension.

Box modeling is a versatile tool to explore earth systems processes, ranging from transient changes in the marine carbonate system to the long-term evolution of biogeochemical cycles. The Earth Science Box Modeling Toolkit is a python based toolkit that allows for the rapid creation and deployment of box models. It abstracts typical modeling tasks, e.g., air-sea gas exchange, weathering, seafloor carbonate precipitation/dissolution, kinetic isotope fractionation, etc., to python classes. Class instances can then simply be combined to build a model. While there is no graphical interface, this approach significantly reduces coding complexity and model development time. Crucially, the model structure is independent of the numerical implementation. Instead the model is parsed to dynamically create the necessary equation systems that can be passed to ode solver libraries like ODEPACK. Separating model description from numerical implementation results in well-documented model code, and combines the computational efficiency of state-of-the-art numerical libraries with the ease of use of python. The efficiency of this process is demonstrated by a 12-box model with air-sea gas exchange, tracers for carbon isotopes, and water column carbonate chemistry that requires about 1 CPU second to calculate the model evolution over 30 million years.

Recently, interest in hydrogen as an emission free fuel has increased. So far, hydrogen is produced by steam methane reforming (SMR), water electrolysis or methane pyrolysis. These processes are energy consuming and SMR emits carbon dioxide. Naturally occurring hydrogen might represent an alternative to technologically produced hydrogen. It is therefore worthwhile to explore whether economically viable amounts of hydrogen are present in the earth.

Whereas a wealth of hydrogen on earth is considered to be trapped in the earth’s core and lower mantle and mostly inaccessible to humans, natural hydrogen also occurs in the crust and upper mantle where it is formed from biogenic and abiogenic sources. Important processes for the generation of natural hydrogen include: water-rock interactions involving ferrous iron, e.g. serpentinization, equilibrium reactions associated with volcanic activity and hydrothermal vents, water radiolysis, mechanochemical reactions in cataclastic rocks associated with fault zones and thermal decomposition of organic matter to form graphite at high temperatures in deep sedimentary basins or crystalline basement.

The presence of hydrogen-rich gas was documented at Mid-Ocean-Ridges, ophiolites, sedimentary basins, and Precambrian cratons. A multitude of studies on natural hydrogen exists, but the relationship between generation, fluid migration and potential occurrence of economic accumulations of natural hydrogen is still a matter of debate.

We present an overview of the current published knowledge on natural hydrogen showing selected study locations of previous works and the amount of naturally occurring hydrogen inferred at each site. The methods used to estimate the amount of occurring hydrogen are reviewed.

Hydrogen, converted from renewable energy sources, provides a feasible road map to balance the daily up to seasonally fluctuation between renewable energy supply and consumer demand. Underground hydrogen storage (UHS) in porous formations is promising since depleted hydrocarbon reservoirs and aquifers are widespread worldwide, and have a large capacity to meet the G-TWh storage demand. However, unlike underground natural gas (mainly methane) storage, hydrogen is highly susceptible to microbial metabolisms, which can consume and convert hydrogen into other molecules such as methane through methanogenesis. This poses a risk of hydrogen loss and contamination. Another concept is geo-bio-methanation directly in the subsurface, enabling stable long-term storage. Both concepts require a thorough understanding of microbial activities within porous rocks. The key questions, including, 1) does microbial growth reduce reservoir performance? 2) is there any effect of minerals and pore microstructures on microbial activities? 3) how do static and flow conditions affect microbe distribution? need to be better elucidated. To tackle these questions, we develop an unconventional real-rock micromodel configured with a thin rock layer in a transparent microfluidic chip. This innovative setup allows us to visualise microbial growth in rocks under a fluorescence microscope. By employing real-rock micromodels, we can overcome limitations related to mineral homogeneity and artificial pore structures. Consequently, this workflow and platform may hence offer new possibilities for studying microbial metabolism in geo-materials and the potential interactions.

Geological hydrogen storage in saline aquifers is necessary due to their large capacities, enabling long-term and short-term storage and providing a secure and cost-effective option for integrating hydrogen into the energy system. Currently, there are no operational saline aquifer storages for hydrogen in Germany. However, there is an urgent need for investigating the desired capacity and performance of hydrogen underground storage facilities in deep saline aquifers as one of the most promising geological environments.

In this study, the sedimentary Stuttgart formation at the Ketzin site in Brandenburg, Germany, is assessed for geological hydrogen storage using an open-source reservoir simulator. The site has already been used for town gas and natural gas as well as for pilot CO₂ storage in the past decades. The experience from these storage operations can be transferred to a potential hydrogen storage system.

The goal of the investigation is to evaluate the influence of geological parameters of the heterogeneous formation such as porosity, permeability, salinity, and capillary pressure on flow rates, quantities as well as on the recovery rate. The range of each parameter agrees with the measured uncertainty of petrophysical data. The results of the pre-feasibility study are then considered in the context of the regional hydrogen economy.

Overall, this multidisciplinary approach combines numerical simulations, geological parameters, and regional economic considerations. Future studies will focus on optimizing the operational parameter to minimize well-head pressure difference between charge and discharge cycles, to maximize production rates, and to achieve net-zero cumulative injection of hydrogen over time.

Despite the high salinity, biological processes could be used in salt caverns for methanation if suitable conditions are created. With suitable backfill materials, growth areas for the formation of biofilms could be created and the availability of sulfate could be reduced. These backfill materials can also be used in the course of cavern containment to reduce convergence.

Large scale experiments enable the simulation of cavern filling with suitable porous materials and the testing of growth material to promote biofilm formation. The aim is to develop an underground methanation reactor that also minimizes the convergence of the cavern. Therefore, it has to be tested if methanogenic archaea can survive under the given conditions.

We use an autoclave system with a volume of ca. 35 liters. Pressures of up to 100 bar and temperatures of up to 100 °C are possible. The autoclave consists of two chambers and a 2.5 m long casing in between. For safety reasons, the gas will contain 95 % N2, 4 % H2 and 1 % CO2. The bottom of the autoclave will be filled with brine and salt. As filling materials, expanded clay and construction waste are foreseen.

The European Marine Observation and Data Network (EMODnet) is a long-term marine data initiative funded by the European Maritime, Fisheries and Aquaculture Fund (EMFAF) and supported by the EU’s integrated maritime policy. The EMODnet Geology team released in 2023 a series of pan-European products related to marine themes including Seafloor geology, geological events, submerged landscapes, and Marine Minerals. Data products are available through the integrated EMODnet Central Portal: https://emodnet.ec.europa.eu/en. Collated marine mineral types and energy resources are: aggregates; hydrocarbons; gas hydrates; sapropel, marine placers; phosphorites; evaporites; polymetallic sulphides; polymetallic nodules; cobalt-rich ferromanganese crust; metal-rich sediments; rock, pegmatite and vein hosted mineralisation. The marine minerals theme is also connected to the five-year EU Coordination and Support Action, GSEU, (EuroGeoSurveys) that will deliver a plan for a sustainable Geological Service for Europe to be implemented beyond the 2027 project end, including assessing Europe’s offshore CRM resources improving the knowledge of underexplored areas and their mineral resources harmonizing datasets and cartographic products with a focus on European strategic and CRM for power generation and energy storage. With Earth’s population growth, efforts to meet our needs for resources with indigenous supplies continue. Many minerals and critical raw materials form important components in low-carbon and resource-efficient technologies such as electric car batteries, wind turbines and solar panels. Information on the types of minerals has relevance to engineering disciplines including extractive industries, beach nourishment and reclamation projects, and more general in Marine Spatial Planning. Environmental and marine EU policies are benefiting from the project’s outcomes.

Polymetallic nodules (including ferromanganese) are one the major metal-bearing sources, those admitted as strategic and critical raw materials (CRMs) by the European Commission. Their widespread on seas’ and oceans’ bottoms entail interests in economic use of them.

Ferromanganese (Fe-Mn) nodules occur on the seabedof most areas of the Baltic Sea. Those from the Polish Exclusive Economic Zone (PEEZ) are ones of least explored elements of the marine environment. Since 2020 there have been 3 research cruises on the area of the PEEZ - on 3 selected areas, 25 km2 each (near Baltic Beta oil rig, Slupsk Furrow and Gdansk’s Basin). Almost 100 sediment samples from the seabed were collected by Van Veen sampler and box-corer. So far, more than 2000 samples of nodules have been described and analyzed.

The main assumptions of the project are to determine:

• mineralogical and chemical compositions, genesis, age;

• geochemical variability of Fe-Mn nodules and their relation to bottom sediments and the morphology of the bottom surface;

• directions for depositional potential based on chemical composition for averaged samples of the areas in the PEEZ.

The chemical investigation (by using of ICP-MS) performed on the new nodule samples from the Słupsk Furrow and the edge of the Gotland Basin showed the average REE content at the level of 164.33 ppm (from 118.40 ppm to 202.74 ppm). There is a visible small positive Li anomaly (from 60.40 ppm to 444.60 ppm).

Further research investigations may redound more data in the context of economic potential.

As part of project D-AERO Finsterwalde, the “Bundesanstalt für Geowissenschaften und Rohstoffe” (BGR) carried out an airborne geophysical study in a former opencast lignite mining area in summer 2021. The area (260 km², 1742 line-km) surveyed using BGR’s helicopter-borne geophysical system (electromagnetics (EM), magnetics and radiometrics) is located about 60 km southwest of the city of Cottbus. The project was conducted in cooperation with “Lausitzer und Mitteldeutsche Bergbau-Verwaltungsgesellschaft” (LMBV) and in consultation with “Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg“ (LBGR). The results (Siemon et al., 2022) include a comparison of the resistivity models derived from EM data with a geological database provided by LMBV and corroborates the validity of the resistivity models.

We present here the first results of “FINA”, a new project by BGR´s „Forschungs- und Entwicklungszentrum Bergbaufolgen” (FEZB) that, among several other goals, aims to make use of the collected helicopter-borne EM information to complement the previous analysis. Using machine-learning algorithms, the EM models are analyzed searching for patterns previously not seen. An in-depth analysis is performed based on geological and geophysical databases, now complemented with geophysical logs and further geological borehole information provided by LBGR. These results will be used in the near future to refine a new 3D geological model of Lusatia currently in development, in order to obtain a better understanding of the water distribution and flow patterns in that region.

The hydrology and hydrogeology of the German Lusatian mining district has strongly been impacted by open pit lignite mining. During active mining, mines are dewatered to lower the groundwater tables below the coal-bearing layers (up to 100 m below the surface). Following the phase-out of current mining activities, groundwater levels will rise and groundwater will reconnect with surface water. The groundwater-surface water interactions strongly influence flow patterns and dynamics as well as hydrochemistry and water quality, and are still largely unknown.

It is therefore planned to systematically select up to five representative post-mining lakes to conduct detailed measurement of climatological parameters and stable isotopes (deuterium, oxygen-18, and sulphur-34). The overall goal of this work (IsoGon project) is the characterization of surface water-groundwater interactions and the quantification of evaporation losses from the post-mining lakes in Lusatia. In this contribution, we summarize our planned project activities, state of the project, current understanding of the subject and our objectives of further planned work.

The EU Water Framework Directive (WFD) demands a good ecological status or ecological potential for natural and artificial lakes larger than 50 ha until 2027. More than 100 artificial mining lakes originate from lignite mining activities in Germany. The specific chemistry of mining lakes with their high phosphorus retention capacity is a chance for the development of clear lakes that are poor in nutrients. For neutral mining lakes, the existing typology for natural lakes which is based on the biological quality elements was adapted. For acidic lakes, the phytoplankton assessment was modified by including the diversity of the phytoplankton. In total, 36 of the largest existing mining lakes in Germany were assessed and description of the limnological lake characteristics were elaborated. Some of the relevant lakes could not be sampled because they are still in filling process and under surveillance of the mining authorities or safety demands for sampling are not given. So far, 53 % of lakes considered in this study reach the good or better ecological potential. Three lakes fail this state because environmental quality standards for river basin-specific chemical pollutants are not complied. Only one lake shows too high trophic conditions. The currently applied assessment tools especially those for macrophytes and microphytobenthos do not meet the requirements for the specific ecological situation in acidic mining lakes. Therefore, these results can only be regarded as an intermediate status of assessment for mining lakes. A revision of the assessment process of macrophytes and microphytobenthos in acidic lakes is recommended.

Laminated sediments of lake Stadtsee, located next to the city Bad Waldsee, provide a unique archive of socio-economic and environmental history since Medieval times. In this study we explored the composition patterns of PAHs and DMP together with the sedimentary charcoal influx records as indicators of variations in natural and anthropogenic fire activity from 1200-1800.

Charcoal particles and organic pollutants are emitted from incomplete combustion in the surrounding area as well as in the city and thus deposited in sediments. Pyrogenic Polycyclic aromatic hydrocarbons (PAHs) can be linked to vegetation types, householdburnings or pre-industrial production. In particular, the co-occurrence of charcoal and PAHs including dimethyl-phenanthrene (DMP) isomers can be used as a proxy to distinguish natural- and human-related historical fire activity. However, this proxy has rarely been applied for the time period before 1800.

Macro charcoal results show 15 screened charcoal peaks, which group into two phases of biomass burning. The first phase in the late Medieval period show high proportions of burned grass and monocot leaves, whereas in the second phase in the early Modern Times wood was the main fire fuel. The obtained PAH patterns, in particular the DMP isomers ratio (1.7-DMP/1.2-DMP), support the change in fuel source. High perylene values in late Medieval time indicate biogenic processes under anoxic conditions and suggests delivery of terrestrial organic material by water.

The Cenozoic cooling that occurred over the past 50 Ma is accompanied by an increase of Mg/Ca ratio in seawater. How this change in seawater chemistry is linked to climate change is still disputed. Mg isotope ratios of seawater could distinguish several possible causes including dolomitization, authigenic clay formation and changes in rates of silicate- and carbonate weathering. Former reconstructions of Mg isotope ratios of paleo-seawater are based on foraminifera, corals or carbonate muds, which however yield conflicting results. Here we assess the suitability of the bivalve Glycymeris as an archive for paleo-seawater δ²⁶Mg (the standardized ²⁶Mg/²⁴Mg ratio). Their potential as geochemical archive advantage arises from their strong evolutionary conservatism, thick shells and a fossil record dating back to the Early Cretaceous. We report Mg isotope signatures of shells of three recent Glycymeris species from the Adriatic Sea that show an increasing fractionation with increasing ontogenetic age, a property that we use to determine δ²⁶Mg of paleo-seawater from fossil Glycymeris specimens.

The aim of our study was to investigate the driving factors for shell growth in G. glycymeris bivalves by analysing the growth patterns and stable oxygen and carbon isotope compositions of shells collected from the Atlantic coast of the Iberian Peninsula.

An increment chronology, covering the 1985-2001 period, was established from the shells and was used to explore longevity and growth responses to environmental parameters. The inter-annual fluctuation of increment widths displayed a positive correlation (r=0.49, p < 0.05) with the regional March sea surface temperature (SST), suggesting that at this collection site, late winter SST is limiting the growth of the studied bivalve species. Significant negative correlations were observed with precipitation (r=-0.69 p<0.05) and also with sea surface salinity (r=-0.59 p<0.05) in February associated with complex hydrological processes of the Iberian Shelf. Intensive regional precipitation in June seems to have a positive effect on shell growth.

Comparing sub-annually resolved oxygen isotope ratios from three specimens with overlapping lifespans (1984-1993) to satellite-derived temperature data proved that summer SST maxima were recorded within the shell carbonate, whereas annual minima are not reflected.

Our results imply that annual growth rates of G. glycymeris shells collected near Aveiro are affected by summer runoff events and late winter SSTs. The latter connection is more difficult to explain as Glycymeris shell growth usually slows down or ceases during this period. Late winter stages of Glycymeris reproduction may affect their sensitivity to late winter SSTs and may have possible consequences for the overall annual shell growth.

During the Early Holocene Humid Period (EHHP), a perennial lake was located in the endorheic depression north of the modern settlement of Tayma in Saudi Arabia. While the climate in this area is arid to hyperarid today, it was arid to semiarid during the EHHP. A deep lake phase occurred around the 8.2 ka BP climate deterioration that led to general cooling and drying on the Arabian Peninsula. Foraminifers and ostracods in the sediments of the sabkha basin represent a brackish to hypersaline inland water fauna, which provides valuable information on the past precipitation/evaporation balance. In the lower part of an analysed core section from the deepest part of the basin, they reflect the beginning of the EHHP with a transition to a more humid phase and the development from slightly saline wetlands to a shallow brackish lake, shown by increasing microfossil abundances, a decreasing adult/juvenile-ratio in ostracods, and an increase of δ¹³C. This culminated in a deep lake phase at ca. 8.3 cal. BP. Varved sediments from two sections contain ostracods and foraminifers which are more abundant in the dark layers, indicating more favorable living conditions during deposition of these layers. This is also indicated by higher frequencies of juvenile carapaces in the light layers, suggesting possibly higher juvenile mortality rates. A sieve pore analysis in ostracods valves proposes distinctly higher salinities during deposition of the light layers. The seasonal variances in the microfossil assemblages may reflect generally dry summers and more humid winters.

Shell carbonates of marine molluscs are a widely used archive for paleo-environmental reconstructions. However, their use for temperature reconstructions may be impeded by species-specific vital effects and/or a lack of knowledge of the chemical and isotopic composition of paleo-seawater. Clumped isotope (∆₄₇) thermometry of marine carbonates enables temperature reconstructions independent of seawater composition provided the carbonate formed in thermodynamic equilibrium. Dual clumped isotope thermometry, i.e. simultaneous analysis of ∆₄₈ alongside ∆₄₇, offers the opportunity to determine if a carbonate formed in isotopic equilibrium and to account for kinetic effects taking place prior to and/or during precipitation. Here, we present dual clumped isotope data for several modern mollusc specimens (including bivalves and gastropods) with average growth temperatures ranging from 5-27°C. We find that most specimens analysed in this study exhibit dual clumped isotope compositions which are indistinguishable from equilibrium. Moreover, their ∆₄₇-derived temperatures agree within errors with their growth temperatures. We interpret the apparent equilibrium calcification of mollusc shell carbonates to be a possible consequence of a relatively low pH at the site of calcification. The absence of any resolvable kinetic isotope effects makes molluscs a reliable archive for highly precise (95CI of <2.2°C) temperature reconstructions via ∆₄₇-analysis. Based on previous ∆₄₇ investigations of molluscs grown at known seawater oxygen isotope compositions (δ¹⁸O_SW), we also determine the temperature dependencies of the oxygen isotope fractionation between seawater and molluscan aragonite/calcite.

∆₄₇ and δ¹⁸O values of fossil molluscs may be used in conjunction with these calibrations to reconstruct both - seawater-δ¹⁸O and temperature.

Tropical cyclones (TCs) such as hurricanes are amongst the most devastating natural disasters of the modern world causing massive humanitarian, ecological, and economic damage every year. A better understanding of timing and frequency of TCs must, therefore, be a key priority for building resilience of affected countries. Within this project, we investigate a stable isotope-based approach for the reconstruction of paleo-TCs through the integration of ecological and morphological data with isotope geochemical signatures of modern ostracodes in relation to the hydrochemistry from a tropical lake located within the Main Development Region of TCs (Lago Enriquillo, Dominican Republic). Water samples were taken during two seasons in 2022 on different vertical profiles through the lake, associated tributaries and closed-by water bodies. Besides in-situ characterization, samples were taken for major, minor, and trace elements using different analytical approaches, and the stable isotope signatures of water (²H, ¹⁸O; CRDS spectroscopy), dissolved inorganic carbon (¹³C; gas mass spectrometry), and sulfate (³⁴S, ¹⁸O; gas mass spectrometry). Hydrochemical data were further evaluated using the speciation model PHREEQC.

Substantial changes in the lake composition were observed between the two campaigns. Together with an evaluation of element stoichiometries, the water isotopes allow for an evaluation of sources and evapotranspiration. Carbon and sulfur isotopes allow to deduce the role of microbial activity and solution-atmosphere exchange on the modulation of the dissolved carbon system, in contact with solid phase carbonates, like ostracod shells

Outcrop and sub-crop evidence from the Lower Triassic Sherwood Sandstone Group (SSG) suggests a northerly flowing braided river deposited pebble-rich red sandstones through several UK basins. Previous workers assume the sole source of this ‘Budleigh Salterton River System’ to be the Armorican Massif, based on dominantly metaquartzite pebble composition, paleoflow orientations and lithostratigraphy trend. However, a proximal to distal facies trend northwards from an Armorican Massif source should mean pebble-sized clasts decrease in abundance northwards, yet pebble-rich sandstones and conglomerates are seen through several basins with slight variations in composition, perhaps indicating that other topographic high areas adjacent to the river system also provide a source for the pebble clasts via tributary drainage systems. This study conducted fieldwork to collect data specifically surrounding clast inclusions pebble clasts, including clast size, abundance, and orientation, to determine if/where possible tributaries occur. Pebble abundance was plotted against distance using Matlab software, with a simple model inversion used to assess the distance from the source. Our results indicate a three source-model is most likely, suggesting local sources are present and significant contributors to the overall sediment budget. Using spatial distributions of pebble abundance, one tributary was likely located from the Welsh Massif and a second from a potential basin margin fault. These results contrast previous models, which suggest the majority of sediment was sourced from the Armorican Massif, and raise several questions about the distribution of Triassic sediment fairways across the UK.

The Adula nappe in the Swiss-Italian Central Alps is a continental basement nappe from the former European margin that was subducted to depths indicating (ultra)-high-pressure conditions. Many studies were performed to understand the pressure-temperature-time evolution of the Adula nappe. The Adula nappe underwent eclogite-facies metamorphism during the Variscan and Alpine orogenic cycles but the Variscan and Alpine parageneses are hard to distinguish.

For this study, around fifty samples were collected from different lithologies on a N-S transect through the Adula nappe parallel to the direction of subduction. Raman spectroscopy on quartz inclusions in garnet was used as a geobarometer to measure minimum peak pressures. This method is independent of chemical equilibria and yields reliable pressure constraints even if the high-pressure mineral assemblage has been retrogressed. Variscan and Alpine garnet domains were identified using the Electron Microprobe and Scanning Electron Microscopy.

The Variscan peak pressure was at least 2.3 GPa. For the Alpine metamorphism, the Zr-in-rutile temperatures exhibit a gradient increasing from ca. 500-550 ^oC in the north to around 700 ^oC in the south. The minimum peak pressures in the northern and central Adula nappe are 2.1-2.2 GPa for metasediments, 1.4-2.0 GPa for metabasites, and 1.5 GPa for an orthogneiss. Lower pressures of 1.1-1.3 GPa in the southern Adula nappe were potentially caused by viscous relaxation of the quartz inclusions during the high-temperature Lepontine metamorphism.

The Saualpe-Koralpe high pressure (HP) complex as well as the HP units of the Pohorje mountains formed during the Cretaceous orogenic cycle in the Eastern Alps. Within these units eclogite bodies can be found, which were probably emplaced along the rift zone that led to the opening of the Meliata ocean. After closure of the ocean ongoing convergence led to underplating within the lower plate, which led to the formation of the Austroalpine nappe stack. During subduction, the Saualpe, Koralpe and Pohorje units reached peak pressure conditions of 2.2-2.4 GPa/630-690°C, 1.8-1.9 GPa/670°C and 3.0–3.7 GPa/710–940 °C, respectively. PT-analyses, microstructural investigations and dating predict different contrasting models for the subsequent exhumation of these units.

Here, we investigate the deformational history of these units during their exhumation. We sampled sets of pristine eclogites, retrograde amphibolite facies shear zones as well as neighboring gneisses surrounding the eclogite lenses. The samples were analyzed by electron backscatter diffraction (EBSD) to determine their crystallographic preferred orientation (CPO) and deformation mechanisms. Both omphacite in pristine eclogites and hornblende in the amphibolite facies shear zones show a pronounced CPO. Hornblende yields distinct signs of dynamic recrystallization by subgrain rotation within the shear zones. Quartz CPO was analyzed in both the eclogites and the surrounding gneiss matrix. Results indicate a shear sense reversal during the exhumation of the Pohorje eclogites.

In this study we show CPO data that recorded the deformational path of these rocks from eclogite facies conditions up to the exhumation to crustal levels.

Understanding collision zones and their geodynamic processes is crucial for comprehending plate tectonics, mountain building, and seismic activities. This study employs the software MDOODZ for numerical thermo-mechanical modelling, specifically designed to simulate the mechanical behaviour and thermal evolution of rocks in 2D complex geological settings.

Focusing on a collision zone, we investigate the influence of anisotropy on geodynamic processes. Anisotropy, resulting from preferred orientations of minerals or rock structures, plays a significant role in the deformation behaviour and mechanical response of stressed rocks. By incorporating anisotropy effects using the director vector and transformation matrix approaches proposed by Mühlhaus (2002) and Fletcher (2005), respectively, we explore its impact on the overall geodynamic evolution of the collision zone.

Our 2D thermo-mechanical numerical model captures the essential dynamics of the collision zone, considering the coupling of mechanical and thermal processes, including rock rheology, heat transfer, and their interactions. Accounting for anisotropic properties enables us to investigate the implications of various orientations and strengths of anisotropy on geodynamic processes within the collision zone.

Our findings contribute to understanding collision zone dynamics, highlighting the significance of anisotropy effects in shaping geological processes. The utilisation of MDOODZ, in conjunction with anisotropy incorporation, facilitates exploring the intricate interplay between anisotropy and thermo-mechanical interactions in collision zones.

Slab detachment is a process that has been invoked to explain rapid uplift, deep seismicity, and magmatic activity in several active orogens (e.g., Alps, Himalaya). However, it is not yet clear to which extent slab detachment is the primary cause of these phenomena. Thus, deciphering the physical processes controlling the slab break-off is important to understand its impact on the post-collisional evolution of orogens.

Here, we employ numerical models to investigate the nonlinear coupling between mantle flow and slab detachment. Due to the three-dimensional nature of slab detachment and the variety of involved processes, it is daunting to pinpoint the first order controls on the time scale of this process. We, therefore, started to investigate this issue by developing a 0D necking model that describes the temporal evolution of the thickness of a detaching slab. We accounted for the effects of the nonlinear coupling between upper mantle and detaching slab and derived a set of nondimensional numbers that control the slab detachment process.

Based on these findings, we, then, used 2D and 3D numerical models to further determine higher dimensional geometrical effects on slab detachment. Results show that the predictions from the 0D experiments predict simple 2D and 3D experiments sufficiently well. For more complex slab geometries, higher dimensional results deviate from the 0D predictions. Nevertheless, the combination of 0D and 2D/3D numerical models allows to determine first order controls on slab detachment and thus also on specific geological observations such as seismicity and surface response.

The KSP Complex in the Eastern Alps is a lithologically heterogenous (U)HP nappe with eclogite lenses embedded in gneisses and metasediments. The formation history of the KSP Complex is still debated. Here, we investigate in detail the pressure and temperature conditions during the formation of the complex along a NW-SE transect following the direction of subduction. This is the first study where quartz inclusions in garnet elastic barometry was conducted to determine the entrapment pressures, which correspond to the minimum pressure conditions present during the entrapment of quartz inside garnet. The eclogites yield pressures of max. 1.9 GPa across the KSP complex, indicating no pressure increase from the NW to SE. The metasediments and gneisses show overall lower pressures with ca. 1.4 GPa. Temperatures based on Zr-in-rutile thermometry do not indicate a temperature increase from NW to SE, with ca. 640 (±30)°C across the whole KSP Complex, based on very similar Zr content of ca. 270 ppm. U/Pb dating on garnets in metasediments provide the following ages for the Koralpe 101.3 ± 6.6 Ma (throughout garnet); Saualpe 224.6 ± 31 Ma (core) and 95.43 ± 5.6 Ma (rim); Pohorje 99.83 ± 5.85 to 104.2 ± 7.1 Ma (throughout garnet). Garnet in eclogite from Koralpe is 112.8 ± 9.9 Ma. Combined with results of previous studies of eclogite ages, we suggest, that the eclogites are former (probably Permian) gabbro intrusions that experienced HP conditions during the Eo-Alpine orogeny. Whereas garnet ages of metasediments from Saualpe provide evidence for a polymetamorphic history.

The elastic interaction between an inclusion and its host is often employed to study the entrapment conditions during metamorphism on the assumption that the host is not affected by creep. However, it is not well understood how fast creep-induced relaxation may occur and under what conditions the elastic regime holds for each crystalline inclusion-host system. In this study, we performed heating experiments on eclogite and spessartine garnets under 1) graphite, 2) N₂+H₂ and 3) H₂O+Ar fluxed conditions at different temperatures. Raman spectroscopy is used to measure the same quartz and zircon inclusions after different heating times. The Raman-band wavenumber undergoes a time-dependent decrease in quartz inclusions and increase in zircon inclusions under H₂O+Ar and H₂+N₂ conditions, but stabilises after the first heating step under graphite-buffered conditions. EBSD results reveal greater misorientation around the heated inclusions compared to unheated inclusions. Raman mapping reveals that stress heterogeneity in the garnet host develops first and fades away afterward, indicating dispersal of dislocations into the host. A visco-elastic model fit to the measured Raman data provides estimates of flow-law parameters for garnet. These results demonstrate the efficiency of H migration and its weakening effect on garnet. The data also indicate that the garnet can be stronger than previously thought under a dry and reduced environment, which is consistent with the high activation energy of Si diffusion in dry garnet. This study provides a critical temperature and water limit for elastic thermobarometry and criteria of determining whether an inclusion has been reset or not.

As part of the retrieval planning of radioactive waste from the ASSE II salt mine, located in the western part of the Asse-Heesberg salt structure south-east of the city of Braunschweig in northern Germany, a detailed and consistent 3D geological model of the internal structure is required. It’s used as a planning tool for the construction of a recovery mine and includes the Zechstein units from the Staßfurt to the Aller-formations (z2-z4). The data basis consists of a multitude of prospecting data such as drill cores, georadar reflectors, 3D seismic and dip values, for instance.

3D geological modelling of salt rock which has been highly deformed by salt migration and tectonical stress as well, faces some challenges. The various layers within the salt rock are strongly folded and overturned in parts. Lithologically different salt bodies often intertwine. The visualization of such complex structures often cannot be realized using conventional 3D modelling software that bases on fixed mathematical algorithms. Thus, details of the internal structure remain disregarded in many cases. Salt model surfaces can be shaped more precisely considering not only the input data, but also the geologic evolution of the salt structure. Therefore, in this project, we use a software (OpenGeo7) that requests complete manual drawing of the isobaths of the model surfaces. In the present study, we present some challenges and results of this type of 3D geological modelling.

The U.S. Geological Survey (USGS) has recently published a guideline for processing coastal imagery acquired by unmanned aerial vehicles (UAVs) based on the widely used Agisoft Metashape Professional software (USGS Open-File Report 2021-1039; Over et al. 2021). The guideline aims to improve the quality of photogrammetric reconstructions by iteratively removing low-quality tie points based on different cleaning parameters. However, the improvement procedure is iteratively performed and requires permanent attendance of the operator. Furthermore, the different cleaning steps are executed on a trial-and-error basis, adding up to the overall attentiveness required.

To minimise the time expenditure necessary for conducting the cleaning procedure and to provide a frame for the reproducibility of photogrammetric product derivations, we have compiled a python script to automate the tie point cloud optimisation as detailed in the USGS report. The graphical user interface of the script allows non-expert users to adjust important cleaning parameters, such as maximum reconstruction uncertainty, minimum projection accuracy and/or maximum reprojection error thresholds, and number of iterations to be performed. Furthermore, main tie point cloud quality measures can be directly assessed. We will demonstrate that the time required to clean tie point clouds (using a computer equipped with a 3.60 GHz processor, 64 GB Ram, and NVIDIA Quadro M4000) can be significantly reduced, such that cleaning of a (unprocessed) ~8 million tie point cloud is achieved unattended in about 30 minutes (default cleaning threshold values used), with ~7 million tie points being automatically removed while significantly increasing point cloud quality measures.

The Halle Fault in central Germany is a major tectonic fault that separates the lower permian rocks (Rotliegend) in the north from triassic rocks in the south. While geological modeling of the Cenozoic and Mesozoic rocks on both sides of the fault has been carried out frequently in the last two decades, the Paleozoic volcanics and sediments of the Permo-Carboniferous rocks in the Halle-Wittenberg-Scholle that outcrop in the urban area have not been modeled in 3D. This study aims to fill this gap by proposing a 3D GIS-based modeling approach to model the geometric and stratigraphic relationship of the volcanic rocks and host-sediments of the Halle-Wittenberg-Scholle.

The approach relies on standard geological data, such as geological maps, boreholes, and digital terrain models, from which geological cross sections are generated and used for further modeling. Existing profiles and seismic data are desired and can bring advantages in the modeling process. While attempts to develop an open-source modeling tool have already been made, they require programming skills, making this GIS-based approach more accessible to a wider audience.

For this purpose this research aims to make the proposed method publicly available, enabling anyone to create a 3D geological model without the need for specialized and costly modeling programs. This approach facilitates an ideal exchange between students and scientists, promoting further understanding and exploration of the possibilities of geological 3D modeling, and also advancing the understanding of the geological features of the Halle Fault.

Ökosystem- und Klimaänderungen sind äußerst aktuelle und brisante Themen, die bei einem großen Teil der Bevölkerung auf breites Interesse stoßen. Bei der Unterscheidung zwischen anthropogen beeinflussten und rein natürlichen Änderungen spielen paläoklimatologische Untersuchungen eine wichtige Rolle. Die Ergebnisse solcher Untersuchungen geben populäre Medien jedoch zum Teil missverständlich oder gar verfälscht wieder. Oft veröffentlichen Medien Ökosystem- und Klimadaten und diskutieren diese, doch die Ansätze zur Ermittlung der präsentierten Daten, ihre Verlässlichkeit sowie ihre Anwendbarkeit bleiben NichtwissenschaftlerInnen oft verschlossen.

Ein guter Weg, interessierten Laien natürliche Klimaänderungen zu erläutern und generell das Verständnis für wissenschaftliche Forschung zu stärken, sind vereinfachte Fallstudien z. B. anhand von synthetischen Pollenpräparaten. Wir stellen solche Studien vor und diskutieren ihre Umsetzbarkeit in Museen, Schulen und der universitären Lehre anhand des Beispiels eines Kurses zur Pollen-basierten Paläoklimaanalyse mit Grundschulkindern, bei dem theoretische Fragen mit Analysen und haptischen Arbeiten verknüpft wurden. Wir legen weiterhin dar, wie solche Kurse in verkleinertem Umfang auch bei öffentlichen Veranstaltungen umgesetzt werden können.

Geoparks serve as an important link between science and the public. Through the lens of geotourism, they not only strengthen regional development and sustainable economics but also offer an interesting encounter with geology and the profound story of our planet’s past. Geoparks provide universal access to the habitat Earth and thereby enhance the respect for nature within society. Since last year the Geopark Ries has been labeled UNESCO Global Geopark, highlighting its remarkable geological heritage on the global stage. The concept of the Geopark Ries is designed to captivate, interest and educate individuals from diverse backgrounds. Even from a very young age, visitors are able to dive into Earth’s history via child-firendly educational programs. Numerous geosites, expert-led tours and thematic hiking trails not only deepen the understanding for the environment and geology of interested locals and tourists but also grant researches and students access to the type locality of Suevite and Riesite.

Therefore, Geoparks play a significant role in raising public awareness regarding the relationship between geology, nature and humanity, thus laying a solid foundation for a sustainable future.

Neben geologischen besitzen Gesteinsgrenzen auch die mathematische Eigenschaft der Gleichheit oder der Kongruenz. Im Einheitskubus des NGS können durch die Mittelsenkrechte vier kongruente Dreiecke in der lotrechten Ebene und vier kongruente Prismen dargestellt werden. Der geometrische Zusammenhang ist begründet durch das mathematische Axiom der Kongruenz. Die Kongruenz der Gesteinsschichtung ist ein rein geologisch begründetes Faktum der Geologie, die Erklärung desselben Bedarfs keiner weiteren Entität.

Der Einheitskubus des NGS erklärt die Verknüpfung des Kongruenzaxioms mit dem Parallelenaxiom in der Geologie. Das Parallelenaxiom ermöglicht den Ansatz der Messtechnik im geologischen Bau, die Einbeziehung des Zahlensystems und somit die axiomatisch begründete Komplexität in der Geologie. Die Veränderung der räumlichen Lage von Gesteinen aus einer ursprünglich horizontalen Lagerung in alle möglichen Schrägstellungen desselben verursachen Schnitte von unterschiedlichsten Flächen und Ebenen im geologischen Bau. In diesen Schnittlinien inzidieren unterschiedliche geologische Flächen und Ebenen miteinander. Die Spuren dieser Schnitte sind Linien der Inzidenz. Auswirkungen geologischer Schrägstellungen der Gesteine können durch das Axiom der Inzidenz erklärt werden.

Die Triade ist ein vollständiges, widerspruchsfreies und kategorisches System von Axiomen.Das NGS, ein mathematisches Objekt der Geologie, erklärt die Zusammenhänge der axiomatischen Triade in der Geologie. I.S. des Mathematikers David Hilbert (1862 – 1943) wird die Geologie durch ein System miteinander verknüpfter Axiome erklärt, das aus den Axiomen der Kongruenz, der Parallelität und der Inzidenz besteht. Die axiomatische Triade ermöglicht die Entwicklung einer "Theoretischen Geologie".

Handheld and portable X-ray fluorescence (XRF) spectrometers have evolved in recent years from being primarily used as metal sorting tools in scrap yards to becoming instruments of high analytical performance. However, this trend has not been fully embraced by the academic and research community, and there are multiple reasons for this. In this presentation we will provide a comprehensive description of the capabilities of these devices, particularly in the context in geo-analysis and archeometric research. We will cover typical analytical performance indicators, including instrument stability, limits of detection, precision and accuracy, as well as reproducibility in quantification. Furthermore, we will discuss how the hardware concept of the instrument influences its performance, allowing for a better understanding of the instrument's capabilities and limitations.

As a practical example, we will focus on the analysis of archaeological ceramics using the TRACER 5g. Ceramic analysis is a common research field in archaeometry that presents additional complexities for accurate elemental characterization. For this application, we will discuss strategies for optimizing measurement time and analytical parameters, tuning existing calibrations for the samples, validating results for publication requirements, and address the challenges of non-invasive analysis of precious artifacts. Additionally, we will explore how the combination of sample characteristics, analytical questions, and XRF physics are directly connected in this context. The presentation will provide a realistic assessment of the analytical performance of portable XRF instruments by offering a robust analytical evaluation that dispels existing myths surrounding this technique.

Fine-grained marine sediments are the largest permanent carbon sink on our planet. We chose the Helgoland Mud Area (HMA) as it represents the most important depocenter of such sediments in the German Bight and hosts a variety of sedimentary habitats that differ in key depositional factors – including water depth, sedimentation rates, grain size and origin of organic matter (OM). The HMA serves as a natural model area to (1) identify the main depositional drivers controlling the burial of organic carbon and (2) assess the efficiency of different sedimentary habitats as natural long-term carbon sinks. During two expeditions with RV Heincke, we collected a total of 16 MUC-cores from different areas of the HMA. Pore-water and solid-phase sampling and analyses were performed - including ²¹⁰Pb_xs to assess sedimentation rates and bioturbation depths, grain-size distribution, TOC contents and pore-water concentrations and stable carbon isotopic composition of DIC to determine the origin of the degrading OM. Sedimentation rates for the past ~200 years range from <0.5 to 6 mm yr^-1 with highest rates in the southern and central part of the HMA. TOC contents typically vary from 1 to 2 wt% with highest values in areas of highest sedimentation rates. The source and reactivity of the degraded OM show large variations, ranging from marine origin in the NW to terrestrial sources in the S of the HMA. The obtained data set will be subject to statistical analysis to determine the key factors controlling the burial of organic carbon in fine-grained North Sea sediments.

In March 2023, the EU Commission proposed a Critical Raw Materials Act. The Act puts a legislative framework in place that addresses security of raw materials supply and provides stability for actors in this field. Its foundation is extensive intelligence gathering and research, allowing for the development of sound a mid- to long-term strategy. This talk will highlight both the provisions of the act as well as the knowledge that underpins them.

The Cadomian accretionary orogeny at the end of Neproterozoic to early Cambrian was one of the principal crustal growth events in Europe, as indicated by a number and widespread distribution of Cadomian basement units within the Variscan and Alpine orogenic belts. Although the evolution of the Avalonian–Cadomian active-margin of northern Gondwana has been well established, geodynamic causes of its collapse and processes of its transition to a passive margin are significantly less understood. The particularly intriguing issues, which have a significant impact on interpretations of paleogeography and course of the subsequent Variscan orogeny, include: (1) how and when the Cadomian orogeny ended, (2) what was the provenance of the Avalonian, Cadomian, and other terranes, i.e., where they started their journey from Gondwana to Pangea, (3) how was the Cambro–Ordovician rifting phase expressed along the former active margin and what was its exact timing, duration, style, and magnitude, and (4) how far east reached the Rheic Ocean rift system and what was the nature of its eastern termination. Integrated geochronological and tectonic information suggest that (i) the active-to-passive-margin transition was step-wise, protracted over Cambrian and early Ordovician, (ii) strongly controlled by tectonic inheritance whereby an inherited suture in the Avalonian ribbon terrane facilitated complete rifting and rift–drift transition while the Cadomian terranes remained attached to Gondwana, and (iii) magmatism may have been an important geodynamic driver of rifting during at least the initial stages, before being overridden by the slab pull force of the subducting Iapetus Ocean.

The nature of Pangea´s internal suture in the Central European Variscides is evaluated on the example of the Harz Mountains (Germany). U-Pb ages of detrital (n = 2273) and magmatic zircon grains (n = 170) were obtained by LA ICP-MS for provenance studies and absolute age dating. Provenance studies point to a docking of East Avalonia onto southern Baltica at c. 430 Ma and to a closure of the Rheic Ocean at c. 430-420 Ma. In the aftermath, the re-opening of a narrow Rhenish Seaway happened in mid-Devonian time. Devonian aged sedimentary rocks of the Harz Mountains were formed at the north-western (Rheno-Hercynian) and on the south-eastern (Saxo-Thuringian) margin of the Rhenish seaway. Deposits formed on the Rheno-Hercynian margin display sedimentary supply from southern Baltica, while most East Avalonian sources were buried and not available for erosion. Siliciclastic shelf deposits of Saxo-Thuringia were derived from Cadomia and its West African hinterland. Provenance studies and spatial arrangement of the tectonostratigraphic units in the Harz Mountains allow to reconstruct the style of obduction of the Harz Mountains onto the southeastern margin of East Avalonia (Rheno-Hercynian Zone). As a result of the closure of the Rhenish Seaway and the collision with the Mid-German Crystalline Zone, the Harz Mountains show a building plan strongly dominated by thin skinned tectonics. Our new data favour a two-plate model for the origin of Pangea´s internal suture in the Central European Variscides, but a re-opening of a narrow oceanic seaway is necessary after closure of the Rheic Ocean.

Convergent tectonics of the Ellesmerian orogeny affected Arctic Canada and Svalbard in late Devonian - early Carboniferous times. The coeval ultra-high pressure metamorphism in NE-Greenland, the formation of the Maritimes Basin in the Canadian Appalachians, and tectonic activity in the Antler orogeny (Nevada, USA), raised a controversy about whether the Ellesmerian orogeny was related to either late Caledonian plate tectonics or renewed, i.e., post-Caledonian convergence of Laurentia with the rest of Laurussia. Here, we argue that the Ellesmerian orogeny represents a far-field effect of the collision of a Gondwanan promontory with the Appalachian segment of Laurussia. This collision caused the decoupling of the North American lithosphere from Laurussia. The northward motion of this lithospheric domain relative to Laurussia explains the tectonic events along its boundaries, namely the Ellesmerian and the Antler orogenies along the frontal and the Panthalassan margins, respectively. Furthermore, it triggered the reactivation of the NE segment of the Greenland Greenland-Scandinavian Caledonides under dextral transpression causing UHP metamorphism. To the southeast, the formation of the Maritimes Basin reflects dextral transtension and associated strike-slip faults parallel to the edge of SE-Greenland. Strain compatibility requires the existence of a dextral lithospheric-scale strike-slip fault that links the tectonic structures and transects the Greenlandian part of the North American Craton. Because this proposed shear zone in SE Greenland follows small-circle trajectories of the motion of Gondwana relative to Laurussia, we interpret the southeastern edge of Greenland as a dextral transform boundary of the decoupled North American lithosphere.

Although the burial of organic carbon in submarine fans and its importance for the carbon cycle have recently received growing attention, our understanding of the mechanisms at play is still lacking compared to other organic carbon storing environments.

Here, we present insights on the distribution of organic carbon throughout marine slope environments from the Arro System, Aínsa Basin (Spain). Evaluation of TOC content by C/S analysis from 82 samples show that there are distinct partitioning patterns of organic carbon between different depositional slope environments and mass transport complexes (MTC). Channel axes are relatively poor in organic carbon (average 0.1% TOC), while overbank deposits are relative enriched (average 0.49% TOC). Intraslope lobes show high variability between their sub-environments. Lobe axis deposits have an average TOC content of 0.13%, lobe fringe deposits 1.21% and the lobe distal fringe deposits 0.55%. Mass transport complexes have an average TOC content of 0.53 %. Integration of Hydrogen Indeces (HI) and T_max, established by RockEval analyses, points towards our samples falling within the range between Type III and Type II kerogen (terrestrial and marine matter), while δC¹³ show a range between 24.5 and 26.5‰, indicating a predominantly terrestrial source.

Our study shows the partitioning of organic carbon across slope environments that are dominated by different depositional processes. The understanding of this variability is important as wrong assumptions about carbon content can be made from studies that ignore spatial differences and potentially lead to false interpretations of climatic/tectonic changes and estimations on carbon budgets.

Provenance studies in the Central European Basin are challenged by the complex geology of source areas. The Variscan orogen represents a puzzle of Cadomian terranes, Variscan-aged domains and Palaeozoic sediments with Baltica-/Gondwana-derived detritus. The Caledonian-Fennoscandian source area comprises the Caledonian Belt, Archean to Neoproterozoic domains (Baltica), Variscan molasse sediments and Permo-Carboniferous igneous rocks.

The low-maturity Schilfsandstein (Stuttgart Formation), composed of first- and second-cycle sands, is an ideal candidate to evaluate provenance tools in a complex setting. Within a basin-scale study, subsurface facies maps, heavy minerals, and U-Pb zircon ages were applied to samples from Germany and onshore UK. Results show that the Schilfsandstein represents variable mixtures of recycled sediments and eroded basement. Heavy minerals are dominated by the Gt-Zr assemblage in North Germany (Fennoscandia), by the Ap-Zr-Ep assemblage in southern NW Germany (Rhenish Massif), and by Gt-Zr, Ap-Zr or Ap-Gt-Zr assemblages in Central and South Germany (Bohemian Massif, Vindelician Land). The clear discrimination of Variscan and Fennoscandian sources based on heavy minerals and subsurface facies maps is less constrained by zircon age spectra. Samples from North Germany either show a mix of Fennoscandian and Variscan spectra or typical Variscan spectra comparable to spectra of samples from Central and South Germany. The statistically identical age spectra of samples from North and South Germany (except UK) suggests mixing of source signals in Schilfsandstein rivers or recycling of Variscan molasse sediments in Fennoscandian catchment areas. The results show that complex source-to-sink settings need integrated approaches, individual provenance tools may lead to ambitious results.

We used original detrital zircon morphology, trace element, and U-Pb age data obtained from Upper Rotliegend II strata (Upper Permian) to reveal sedimentary fluxes within the Central German Basin. Understanding the evolution of such a system is crucial for further studies, given that the North German Basin is storage to vast natural gas resources and may also serve as an intermediary sedimentary repository for younger strata.

The detrital zircon dating results revealed the presence of main age clusters from the Permian, Carboniferous, and Cambrian periods. Additionally, several minor clusters from the Neo-, Meso-, and Palaeoproterozoic eras were also identified. These ages are remnants of the Cadomian and Variscan orogenies and the opening and closure of the Rheic Ocean. Zircon grain morphologies varied from completely unrounded to completely rounded grains across the age range. The heterogeneity of the data obtained from the studied mineral grains is vital to understanding the sedimentary history of the Central German Basin. It suggests that the basin fill is most likely a mixture of repeatedly recycled material and directly derived material from bedrock sources.

The detrital zircon trace element data support these findings, showing a wide range of values indicating different magma sources. These results underline the complexity of detrital zircon, and shed further light on the sedimentary history of the Central German Basin. We also found that the North German Basin is an integral part of a sedimentary recycling system spanning Central Europe, which is active since the Neoproterozoic.

The Paleoarchean Moodies Group (ca. 3.22 Ga) of the Barberton Greenstone Belt (BGB) is the oldest known well-preserved, shallow-water siliciclastic sequence on Earth. Proximal-to-distal textural and petrographic examination of selected units across adjacent terrestrial, coastal, and shallow-marine depositional facies of this strongly deformed unit provides the opportunity to constrain Archean weathering conditions by source-to-sink analysis, complementing previous bulk analyses. We examined conglomerate, sandstone, and shale composition by detailed geologic mapping and facies analysis along progressive downdip sediment routing systems, after excluding regions of syndepositional hydrothermal alteration. The majority of quartz and feldspar grains in the central BGB was sourced from intermediate to felsic intrusives and (sub-)volcanics of the Hooggenoeg Formation of the Onverwacht Anticline (OA). Downdip textural and mineralogical maturation from immature, F-, L- and matrix-rich, coarse-grained debris-flow-style units to texturally and compositionally supermature fine-grained sandstone occurs within a few km; facies belts fringe the OA. Chemical weathering and mechanical disaggregation of latite-dominated clast populations in proximal facies accompanied decomposition of F to clay (now partially preserved as sericite grains) and of intermediate volcanic grains to quartz-sericite-mosaic grains within a few km from their source. Energetic reworking in wide coastal-facies belts winnowed the abundant clay from the sediment and generated supermature sand, possibly aided by high tides. We deduce that Moodies Group sediment generation appears to have occurred in an aggressive weathering environment; in the coastal zone, only sediment which was silicified surficially and pre-compaction escaped transformation to a sedimentary “restite”.

The southern Baltic Sea between the German and Polish coast in the south and the Danish and Swedish coast in the north comprises the well-investigated structural-geological situation along the Tornquist Fan area. Different tectonic features tell the story of this polyphase activated weakness zone, like the Paleozoic Tornquist Zone in the NW, Mesozoic NE trending fault zones or salt structures with crestal grabens above, such as various Late Cretaceous to Paleogene inversion structures.

Time-migrated reflection seismic sections indicate neotectonic activity and fault reactivation, a fact supported by recent earthquakes and ongoing isostatic movements of up to 1 cm/a. Due to the reduced resolution of this thin Quaternary layer within the seismic sections, the fault activation could not be dated more precisely so far. Stress variations of the existing background stress are assumed to result from glacial isostatic adjustment (GIA) processes within the lithosphere. This study analyses fault reactivation due to GIA, covering the past 200 ka. For the first time, this glacially triggered faulting could be studied and compared on a variety of faults that differ in their strike and dip direction, age, depth, and character. Using finite element simulations, we tested if and when faults were reactivated during ice advances and retreats within the European Saalian and Weichselian glacial phases.

So-called ‘blind’ faults, which are not visible at the Earth’s surface may be the source of unexpected and potentially disastrous earthquakes and thus represent a major hazard, especially in urban areas. Detecting such hidden faults is highly important for the seismic hazard assessment of a region, but often remains a challenge, because the faults are covered by young sediments. To overcome this limitation, we visualize blind faults in the area of the Sorgenfrei-Tornquist Zone in northern Denmark with shear-wave seismic reflection surveys. The faults on the seismic surveys are interpreted based on systematic reflector offsets, the presence of continuous transparent zones that separate individual fault blocks, abrupt lateral changes in the reflector pattern, and the presence of fault shadows. The seismic surveys give evidence for a near-surface strike-slip fault system, based on the presence of flower structures and the dominance of steep faults. The distribution of the faults on the seismic surveys and the occurrence of fault-related shear-deformations bands that occur in outcrops along the nearby seas-cliff, together with fault-related basins that are developed in the study area, indicate that the northern boundary fault of the Sorgenfrei-Tornquist Zone is not an isolated fault, but a wider fault array. The study demonstrates that the shear-wave reflection seismic method is a powerful tool to image near-surface faults and is very suitable for palaeoseismological studies. The significantly improved resolution of shear-wave seismic surveys compared to those of the common P-wave reflection method is an advantage, especially in the case of small fault displacements.

Given the increasing challenges posed by climate change, especially more frequent and severe droughts experienced globally, effective exploration and management of groundwater resources is essential to ensure a sustainable and resilient society. As part of this effort, it is necessary to acquire comprehensive knowledge of the distribution of significant and readily accessible freshwater reservoirs on continents. This outlines the critical need for an efficient and cost-effective imaging method to assess this vital resource. In response, we propose a novel imaging method that utilizes observations of air-pressure-induced seismic velocity changes. We utilize findings of our study (Kramer et al., 2023) which shows atmospheric tides and their interaction with the groundwater body are the primary cause of sub-daily seismic velocity changes. Analyzing these velocity changes can reveal valuable information on the hydro-geophysical properties of the underlying groundwater body. Building on this knowledge, we introduce this imaging method and apply it to the seismic data collected across South and Central Europe. For this purpose, we use coda-wave-interferometry to investigate four years of continuous data from AlpArray and other locations throughout Europe.

Kramer, R., Lu, Y., & Bokelmann, G. (2023). Interaction of air pressure and groundwater as main cause of sub-daily relative seismic velocity changes. Geophysical Research Letters, 50, e2022GL101298. https://doi.org/10.1029/2022GL101298

The Mekong Delta, including Ca Mau province in the south, faces severe land subsidence, attributed in part to the excessive groundwater extraction. Addressing this issue requires finding alternative water sources while considering technical, environmental and social challenges. This study aims to understand the significance of groundwater to the people of Ca Mau, their water usage habits and awareness with environmental issues. Supported by local Provincial People's Committees, a comprehensive survey and group interviews were conducted across 9 districts of Ca Mau province. The research aimed to identify the spatial distribution of the required water management solutions and acceptance levels of alternative water resources. Water samples were collected and analyzed to establish the connection between water quality and people's water usage habits. Groundwater plays a vital role in people’s life, serving various purposes such as washing, cooking, drinking, and other activities. Groundwater usage depends on people's perceptions of its quality. For activities requiring higher levels of hygiene, additional water treatment or alternative water sources are preferred. The analytical approach from general viewpoints to details in this study investigates deeper into the story behind their water usage habits. It emphasizes the need to inform people about environmental challenges and raise awareness of cause-effect relationships. Evaluating alternative water resources and designing new water utilization concepts is based on local demands and willingness to change water-related habits. This research sheds light on people's awareness and concern while providing valuable insights for sustainable water management strategies in the Mekong Delta, specifically in Ca Mau province.

With escalating global freshwater scarcity, the Mekong Delta basin has emerged as one of the most socially and ecologically vulnerable regions, experiencing severe freshwater stress and storage loss. This vulnerability is primarily driven by the progressive "loss of land and freshwater" phenomenon, which encompasses a range of interconnected environmental issues, including land subsidence and seawater intrusion. The exponential growth in population, urbanization, climate change and rapid industrial and agricultural development has significantly increased the demand for freshwater, placing already limited supplies under immense pressure. In the coastal zones of the Mekong Delta, groundwater has become the primary and increasingly overexploited source of freshwater. Consequently, a decline in hydraulic heads and the threat of saline intrusion have become pressing concerns. To gain a comprehensive understanding of the hydrogeochemical processes at play, a meticulous investigation was conducted in the coastal province of Ca Mau, Vietnam. Through extensive sampling campaigns and rigorous hydrogeochemical analysis, this study sheds light on the intricate dynamics of groundwater chemistry in the region. The results reveal that ion-exchange processes and the decomposition of organic matter play dominant roles in shaping the groundwater chemistry. These findings hold significant implications for the sustainable management of water resources in the Mekong Delta. By unraveling the past and current hydrogeochemical groundwater dynamics, stakeholders can develop effective strategies to mitigate freshwater scarcity. The knowledge gained from this research contributes to the scientific understanding of hydrological systems and aids in the formulation of integrated water management policies for the region's long-term sustainability.

The transboundary Cuvelai-Etosha Basin (CEB), located in Southern Angola and Northern Namibia, is part of the Kalahari Basin, one of the world´s largest intracontinental basins. It contains mostly unconsolidated sandy sediments, often deposited by so-called megafans. The most prominent one in the CEB is the Cubango Megafan (CM). Megafans can contain large aquifers and thus have huge potential for water supply, especially in semi-arid regions. The CM hosts three aquifers: a locally present, perched aquifer, a regional mostly unconfined and a deep confined aquifer.

The regional climate is semi-arid, with very high evapotranspiration (> 2000 mm/yr) that far exceeds the highly seasonal and variable precipitation (400-800 mm/yr). The widespread salinity in the contemporary groundwater of the CM can be attributed to both sub-recent and co-sedimentary evaporative processes.

In the lower parts of the CEB, specifically at the southwestern rim of the megafan towards the Etosha Pan, saline groundwater predominates. Hydrochemical data indicate large-scale and long-term ion exchange processes. Together with environmental tracers, this shows that younger groundwater infiltrating to the north of the basin is slowly displacing the originally brackish-saline pore water. ⁸¹Kr ages range between 40 to 170 ka indicating the fossil nature of this resource. Analysis of stable isotopes and noble gases reveals that climatic conditions during recharge of the confined aquifer were approximately 3 – 5°C colder than today.

Considering the population growth and predicted impact of climate change on water availability, careful management of this vulnerable and only partially replenishable resource is advisable.

Methane (CH₄) is an important greenhouse gas, but our understanding of the magnitude of its sources is fraught with considerable uncertainties. Quite neglected in early atmospheric methane budget studies, Earth’s degassing is today considered a major natural source of methane. Geological (natural fossil) methane emissions, including gas seepage in petroliferous sedimentary basins (macro-seeps, microseepage, marine seepage) and geothermal exhalations, were estimated at the global scale by several research groups, based on bottom-up and top-down procedures, and accounting for ~40-50 Tg CH₄ yr^-1 (latest review and discussions on conflicting estimates are in Etiope and Schwietzke, 2019, and Thornton et al. 2021). This value is equivalent to roughly one-third of the average emission attributed to wetlands, and it rivals with the high uncertainty of freshwater sources. Global gridded mapping was developed to provide the spatial distribution of the geological methane sources, as well as their isotopic (¹³C/¹²C) composition and potential intensity (Etiope et al. 2019), and it has been used to refine fossil fuel industry and microbial CH₄ emission budget. Geological emission breakdown at continental scale could be derived (e.g., Petrescu et al. 2023), with the emission values that must be considered only in terms of “order of magnitude”. The geo-CH₄ sources are now included in the methane budget of the Global Carbon Project (Saunois et al. 2020), where they are compared to other natural and anthropogenic sources, including an analysis of double-counting with some biological sources. Correct definitions, source attribution, uncertainties and limits define the roadmap strategy for refining emission estimates.

In spite of the decreasing production, Romania remains one of the most important oil and gas producers in Europe. The European inventories of anthropogenic methane release reveals unexpectedly high emissions related to the oil and gas industry in Romania. The number of drilled wells in Romania is exceeding 60,000, with the majority of them currently being inactive. A first approach to quantify the methane emissions from active wells was conducted within the ROMEO project. The highest emissions were observed at the facilities with poor technical maintenance. As part of the UNEP-funded project Global Analysis of Methane Emissions from Abandoned Oil and Gas Wells, an evaluation of methane release from inactive wells is ongoing. No comprehensive inventory of the inactive wells is available for the moment at a national level. The ENVERUS (DrillingInfo), database provides information on 6348 wells in Romania, out of which 776 wells in the Transylvanian Basin. More than 72% of the reported wells were dry, while different amounts of oil and/or gas have been found in the others. According to the nationally applicable closure procedure, most of the wells are plugged and buried, making their identification and detection of gas leaks difficult. In a few cases, substantial methane emissions have been reported, which may pose a threat to neighboring residents.

Acknowledgment: this contribution was supported by the project Global Analysis of Methane Emissions from Abandoned Oil and Gas Wells, funded by UNEP.

All hydrocarbon reservoirs leak slightly. At sites with only minor leakage the hydrocarbons (HC) infiltrating the sediment from below are completely metabolized before reaching the sediments surface due to microbial activity, thus not creating any surface manifestations, e.g. seeps. Nevertheless, the HC influx will change geochemistry as well as microbial community composition and activity in the affected area because electron donors are added into the system. The PROSPECTOMIS project wants to detect these changes to develop a minimally invasive and low-cost tool do detect HC reservoirs using omics and geochemistry techniques.

In November 2021 we recovered fifty 2-3 m long sediment cores from three minor HC seepage zones and two non-seepage reference zones in the southern Barents Sea and sampled sediment and pore water with high spatial resolution.

While Fourier-transform ion cyclotron resonance mass spectrometry and cell abundances did not show any differences between HC seepage zones and reference zones, multiple pore water concentration profiles e.g. for Manganese, Calcium, Silicon, Strontium, Sulfide revealed differences. Also, higher fluxes of sulfate and alkalinity in HC zones indicate that the sink for sulfate and the source of alkalinity must be shallower in HC zones, most probably caused by anaerobic oxidation of methane (AOM) below the sampled depth interval. Linear sulfate pore water profiles indicate no net turnover of sulfate. Nevertheless, we observed low rates of sulfate reduction using radiotracer incubations, mostly in HC zones.

Combining these parameters with multi-omics datasets will reveal potential indicators for minimal HC seepage.

The crystalline basement below the giant Norwegian Troll field has been subject to research and publication for many decades. Still no well bore has penetrated the deep crystalline basement. An ever-increasing amount of geophysical information, documents pronounced basement heterogeneity. The seismic reflection patterns suggest the presence of mappable fluid reservoirs within metamorphic basement rocks.

High-reflection-low-density geobodies appear to be connected to major detachment zones with varying seismicity, but avoiding younger transform lineaments. The features are considered to have formed during the collapse of the Caledonian mountains, opening the precursor basins of the North Sea and the Northern Atlantic Ocean. The structures are partly inherited from contractional features, formed during the Caledonian continental collision between Baltic and North American plates. Former and present-day fluid migration, using this inherited deformation pattern, is significant for understanding the development of one of the most important energy sources for Europe.

While earlier speculations about origin and significance of the strong seismic reflections had to be based on presumed analogues on the Norwegian mainland, we will present evidence from new, high quality seismic, gravity, magnetic and magneto-telluric data and propose new working hypotheses for their geologic origin. Pointing to low density, low magnetism and low resistivity, our mapped „geo-bodies“, could form fluid reservoirs that have influenced the regional development of the Greater Troll area.

Remnants of Earth’s juvenile continental crust are preserved in the form of Archean Tonalite-Trondhjemite-Granodiorites (TTGs). However, much controversy surrounds the composition of TTG protoliths and whether the geodynamic setting involved convergent-style plate tectonics. Thus, a combination of high-pressure and high-temperature experiments combined with robust geochemical proxies are required to gain insight into TTG petrogenesis. Numerous experimental studies have demonstrated that partial melting of hydrated basalt at 0.8 to 2 GPa is sufficient to produce TTG-like melts. The compositions of starting materials used in these experiments vary significantly between studies and has profound implications for the solidus, melt composition, and the type, composition and modal abundance of solid phases. This is problematic especially given most studies have utilised MORB-like starting compositions, which differ significantly in composition to the least altered Archean metabasalts which posses higher MgO and lower Al₂O₃. We present the results of partial melting experiments conducted at 1-1.5 GPa and 940 to 1100 °C in a piston cylinder apparatus using synthetic starting materials with varying H₂O (4-6 wt.%), based on the compositions of Eoarchean metabasalts from the Isua supracrustal belt in southern West Greenland. The run products of these experiments will be analysed to assess their phase assemblages and melt composition, and to constrain the magnitude of mineral-melt trace element and isotopic (Ti) fractionation during partial melting. Ultimately this experimental campaign will ascertain if partial melting of high-Mg, low-Al metabasalts is a viable mechanism to produce melt compositions resembling those of Archean TTGs.

The mainland Lewisian Gneiss Complex (LGC) in NW Scotland is dominated by Archean tonalite-trondhjemite-granodiorite (TTG) gneisses. It consists of at least three distinct crustal blocks that have different magmatic and metamorphic histories. The LGC is regarded to either represent i) a once-contiguous fragment of Archean crust that was later disaggregated and reassembled along major shear zones into the northern, central and southern regions, or ii) a collage of discrete terranes. To better assess the tectono-magmatic evolution of the LGC, we use in situ U-Pb, Lu-Hf and trace element analysis of zircon grains derived from a representative set of TTG gneiss samples. The crystallization ages of TTGs range between 2778 and 2609 Ma in the northern region (Rhiconich terrane), 3003 and 2731 Ma in the central region (Assynt/Gruinard terranes), and 3110 and 2675 Ma in the southern region (Rona terrane). Zircon εHf_(t) values of the oldest samples from the southern region are broadly chondritic. Samples from the southern part of the central region (Gruinard terrane) are more radiogenic, indicating a major period of juvenile magmatism at c. 2900-2800 Ma. Zircon derived from TTGs < 2800 Ma is characterised by chondritic to sub-chondritic Hf isotope signatures, pointing to increased crustal reworking during the late stages of TTG magmatism. Collectively, our data show that TTGs in the different parts of the LGC formed at different conditions and from different sources. We propose that the LGC is composed of at least three terranes that were assembled during the Neoarchean to Paleoproterozoic.

The tectonics on the Archean Earth is intricate and contentious, with ongoing debate concerning the dominant surface processes controlled by either a plate tectonics regime or alternative forms of tectonics (stagnant lid, heat pipe, drip tectonics, sluggish plates and other planetary modes of heat loss). In this study, we assess the viability of interpretations of tectonics during the Archean using a newly compiled metamorphic database. We relate Archean cratons and continental history, crustal growth and reworking, and horizontal motion of ancient cratons to infer which tectonic styles and processes operated. Our analysis is synthetized by the highlighting of three distinct Archean periods with different tectonic activity, starting at 3.8 billion years (Ga), from when the first metamorphic data are available. We find that in the interval 3.8-3.5 Ga, tectonics was dominated by short-lived subduction tectonics and non-subduction tectonics, possibly in cohabitation. Between 3.4 and 3.0 Ga, subduction was present and contributed to the lateral growth of the continents. In the 2.8-2.5 Ga period, the assembly of supercontinent/supercratons signals the action of modern-style plate tectonics. In summary Archean metamorphic data allow timing the Earth progression from pre-modern tectonics to modern plate tectonics including the supercontinent cycle.

The Dwalile Supracrustal Suite of the Ancient Gneiss Complex (Eswatini) represents one of the oldest greenstone belts in the world with a crustal evolution history from Palaeo- to Mesoarchaean times. The main metapelitic rock type is dominated by garnet and staurolite porphyroblasts in a layered matrix of biotite, muscovite, quartz and retrograde sericite. Minor components are andalusite, chlorite and chloritoid with accessory ilmenite and monazite. The age for the amphibolite facies metamorphism is recorded by monazite at ca. 3.15 Ga.

The garnet-staurolite bearing metapelites have thus similar mineralogy and bulk rock compositions, but differ due to their unusual garnet microstructures. In some samples the garnet grains are distributed as thin layers consisting of elongated ribbons, with local resorption textures and peninsular features together with coarse recrystallised quartz. The euhedral garnet cores are only visible in compositional maps, which show a typical bell-shaped growth zoning.

EBSD maps of the crystallographic orientations of the garnet are created for four samples and two samples were imaged using high-resolution X-ray tomography for the visualization of the garnet morphology in order to test the relationship of the garnet porphyroblasts and consider the implications for the formation mechanism. For example, do the garnets share the same crystallographic orientation or is there evidence for deformation and/or rotation processes during growth. How are the garnets orientated in 3D space and are the ribbon textures build up by subgrains caused by deformation or are they separate grains formed by multiple nucleation events, possibly caused by fluid-rock interaction processes.

Eoarchean peridotites from the area south of the Isua Supracrustal Belt (SOISB) in southern West Greenland have been found by previous studies to contain sulfur subject to mass independent fractionation (MIF-S), with positive Δ³³S values indicating that these rocks have incorporated sedimentary sulfur recycled from Earth’s surface [1]. New in-situ secondary ion mass spectrometry measurements of sulfide grains found within these peridotites reveal that this MIF-S is hosted within the sulfide grains. Electron microprobe analyses of the sulfide grains reveal that they are predominantly composed of pentlandite and pyrrhotite, consistent with the typical sulfide mineralogy of mantle rocks. The peridotites displaying the least petrographic evidence for melt overprint (Group 1) were found to contain the highest average in-situ Δ³³S values, +0.20±0.02‰, while those bearing more evidence for melt overprint (Group 2) had lower average in-situ Δ³³S values, +0.09±0.03‰. These findings are in good agreement with previous bulk rock S isotope results [1]. In-situ Pb isotope measurements of the sulfide grains reveal unradiogenic compositions consistent with an Archean origin. Furthermore, petrographic observations reveal that the sulfide grains are crosscut by amphiboles, indicating that the sulfide grains predate Neoarchean amphibolite-facies metamorphism. Our data support previous interpretations that these rocks are the oldest known mantle peridotites. These findings reinforce previous interpretations that SOISB peridotites preserve evidence of crustal recycling in the Eoarchean.

[1] Lewis et al. (2022) EGU 22-5226

The Carnian Pluvial Episode (CPE, 234–232 Ma) was a major climate change event in the Triassic. The CPE brought substantial changes in ecological community structure and the appearance of many key groups dominating modern marine and terrestrial ecosystems. Here we present an interdisciplinary study of Upper Triassic strata in the Tethys realm to reconstruct the vegetation history and infer environmental changes during the Carnian. Furthermore, we applied Mercury (Hg) concentrations and Total Organic Carbon (TOC) to unwrap the role of volcanic activity as a major driver of this episode of climate warming and environmental perturbations. Palynological and paleobotanical data collected from the Northern Tethys (Kope-Dagh basin, NE Iran) show a shift towards hygrophytic elements reflecting the expansion of wet habitats on the continent during the latest early Carnian to late Carnian. The sedimentological and palynological patterns and plant fossil assemblages in the Northern Tethys closely resemble those observed in Western Tethys during CPE. This record represents the only clear record of the CPE in the Iranian plateau. Our geochemical data from Carnian marine sedimentary sequences of the Western Tethys demonstrate discrete spikes in Hg/TOC ratios during the CPE. The results suggest a direct link between the CPE and repeated pulses of the Wrangellia submarine Large Igneous Province that could have played a major role in the evolution of biota and the environment at that time. However, despite progress in understanding the CPE, significant uncertainty remains in addressing how the volcanic eruptions influenced different ecosystems/biotic communities, which deserves further studies.

Even if the knowledge of Triassic tetrapod communities and their role in terrestrial ecosystems has increased in the recent decades, the paucity of fossil sites from this time interval has hindered their complete understanding. In order to shed light on how the Triassic tetrapod communities were, evolved and interacted in their habitats, we are carrying out a series of multidisciplinary studies on the Ladinian Lower Keuper successions (Erfurt Formation) of southwestern Germany. These facies were deposited in a vast epicontinental platform of the Central European Basin, influenced by the Tethys Sea. The Lower Keuper in the study areas consists of a 20–25 m thick succession of alternating siliciclastic and carbonate deposits, mostly grey to green mudstones and marlstones, and yellowish to blueish dolostones, as well as occasional sandstones. The succession is divided in more discrete units, some of which forming exceptional fossillagerstätten with thousands of tetrapod remains recovered and tens of new tetrapod taxa (including basal members of different lineages) described to date. Sedimentological, taphonomic and palaeoecological data show that ecosystems were complex, with several levels within the trophic chain and including at least two top predators: a pseudosuchian archosaur and a giant capitosaur temnospondyl. Of note, fish diversity is particularly high, with at least 14 taxa so far known. The occurrence of the same vertebrate taxa, but in different proportions and from different ontogenetic stages throughout the stratigraphic succession and in different localities corresponding to slightly different environmental settings, indicates stability of the ecosystems.

The Norian Trossingen Plateosaurus bonebeds have piqued the interest of many researchers over the past 100 years. Several investigations took place in the 1910’s to 1930’s excavating over 80 skeletons, but was then left to rest until 2007. In 2007, 2008 and 2010 small excavations took place, resulting in one and a half skeleton of Plateosaurus trossingensis. The depositional environment of the site has had a controversial history with several theories, ranging from a sandy desert to a catastrophic mudflow, to a watering hole with a muddy bottom. In the summer of 2022 an exploratory investigation was performed at the Trossingen site to prepare for large scale excavation in 2023, which will incorporate stratigraphical, sedimentological and taphonomic investigations to further dive into the evolution of the environment and its relation to the fossil remains. Here we present the first results of both the 2022 and 2023 field campaigns with a revised depositional history. The preliminary investigations in 2022 already showed the section is not as homogenous as previously thought and uncovered several structures, most of which not previously recognised, such as: (1) several small channel–like deposits likely of fluvial origin and (2) a carbonate layer with a possible lacustrine origin in the lower beds, (3) large pedogenetic carbonate nodules in the middle beds, and (4) large mudcracks in the upper beds. All these features, together with preliminary taphonomic data from the bones, suggest a potential upwards aridification trend across the entire section.

The sauropodomorph-bearing localities from the Norian-Rhaetian of Europe have been traditionally interpreted as monospecific, attributing the morphological disparity in Plateosaurus to intraspecific variability. The Norian and Rhaetian stages are currently not chronostratigraphically defined, making comparisons between the different deposition environments cumbersome. However, from the base of the Norian to the Rhaetian, the sizes of sauropodomorphs increase, with small to medium-sized sauropodomorphs found in the oldest layers of the Löwenstein Formation, to larger and more robust-sized sauropodomorphs from the Tübingen Sandstone (Rhaetian). This contribution presents the results of a basin analysis to reconstruct the environmental changes in the Germanic Basin during the Late Triassic, integrating stratigraphy, fossil record and structural geology. The results of this are that during the Carnian, the opening of Meliata, Pindos and Maliac Oceans in Western Pangaea created rift zones on the carbonate platforms. Towards the Norian, the sea-spreading ceased as these southern oceans started to close just before the new rifting of the Neothetys began. The complex fault systems generated an epicontinental sea that separated portions of Europe as an archipelago that fully developed when the Rhaetian Sea occupied the Germanic Basin. Independently, several iterations of specimen-level phylogenetics of sauropodomorphs found that the three specimens that have been traditionally referred to as Plateosaurus are placed at the base of a comb-like arrangement that includes robust forms, such as Schleitheimia and Tuebingosaurus—two sauropodomorphs that have been previously nested within sauropodiformes. The phylogenetic patterns in a comb-like arrangement suggest a combination of vicariance and migration in the archipelago.

The rise of dinosaurs during the Late Triassic was a pivotal event in the history of life on Earth, which led to them becoming dominant members of terrestrial ecosystems throughout the remainder of the Mesozoic. However, the drivers of this geographic expansion and explosion in biodiversity have been poorly understood. Early studies have hypothesized that the extinction of co-occurring vertebrate groups such as aetosaurs, rauisuchians, and therapsids at the end-Triassic mass extinction, provided early dinosaurs with the opportunity to diversify into new niches. However, this pattern could instead be a response to climatic changes during this interval, especially given the increasing evidence that climate played a key role in constraining Triassic dinosaur distributions. Our work is the first to quantitatively explore the opportunistic expansion model by examining changes in dinosaur and tetrapod ‘‘climatic niche space’’ across the Triassic-Jurassic boundary. We found that Late Triassic sauropodomorph dinosaurs occupied more restricted climatic niche spaces than other dinosaurs, and were excluded from the hottest climate zones at low latitudes. The geographic expansion of sauropodomorphs after the mass extinction is linked to the expansion of their preferred climatic conditions. Evolutionary model-fitting analyses provide evidence for an important evolutionary shift from cooler to warmer climatic niches during the origin of Sauropoda, the clade that later in the Mesozoic became the iconic long-necked forms. Together, our results provide support for the key role of climate in the ascendancy of dinosaurs.

The temporal geochemical record of Zealandian alkaline intraplate volcanism reveals a significant geochemical evolution from Cretaceous HIMU (high time-integrated μ = ²³⁸U/²⁰⁴Pb Mantle) end member to Cenozoic HIMU-like volcanism with overall lower ²⁰⁷Pb/²⁰⁴Pb and variable ²⁰⁸Pb/²⁰⁴Pb ratios at a given ²⁰⁶Pb/²⁰⁴Pb ratio. In general, this temporal geochemical evolution has been reconstructed by piecing together volcanism taking place at many different localities covering different but limited age ranges. The Chatham Islands, covering an area of ~800km², represent the only known locality within Zealandia where volcanic activity has taken place nearly continuously over ~85 Ma and record the geochemical evolution from HIMU end member to HIMU-like volcanism. Therefore, the Chatham Islands are a key locality for reconstructing and understanding the geochemical evolution of Zealandia. Numerous models, such as an asthenospheric heritage (e.g. mantle plume) or metasomatic overprint of the SCLM by: 1) subduction zone fluids or 2) interaction with Hikurangi Plateau, have been proposed, but the style of geochemical change (abrupt or progressive), as well as the origin of the HIMU end member and HIMU-like sources remain enigmatic, as is the unique longevity of intraplate volcanism over ~85 Ma at a single locality. Geochemical analysis (major and trace elements, radiogenic Sr-Nd-Pb-Hf isotope ratios and mineral composition) of alkaline lavas and enclosed mantle xenoliths from the Chatham Islands, will be used to reconstruct their spatio-temporal geochemical evolution of HIMU to HIMU-like volcanism on the Chatham Islands and associated volcanism on Zealandia over the last ~85 Ma.

Garnet in alkaline igneous rocks is of interest due to its compositional and textural variability that provides insights into magmatic and hydrothermal processes. This study investigates textures and mineral chemistry of garnets from the Tezhsar Alkaline Complex (Armenia) to constrain their petrogenetic origin by determining whether the garnets are a primary magmatic liquidus phase or whether they have a secondary, subsolidus origin. Element mobility during garnet formation is evaluated, focusing on rare earth elements (REE), for which alkaline igneous rocks are a globally important resource and which are a valuable geochemical tracer to understand the evolution of rock-melt-fluid systems.

In the Tezhsar Alkaline Complex, K-rich plutonic and volcanic rocks occur in concentric units, representing the remnants of a palaeocaldera (Sokół et al., 2018). Garnet occurs in euhedral to subhedral clusters in pegmatitic nepheline syenite and more rarely as phenocrysts in syenites. The calcic garnets have a high Ti content (c. 2-4 wt.% TiO₂), which is typical for garnet in alkaline igneous rocks. Garnet in the pegmatitic nepheline syenite is devoid of inclusions and shows only limited chemical variability, interpreted to reflect crystallization from a melt. In the syenite, garnet is rich in mineral inclusions and is interpreted to reflect a metasomatic origin during late/post-magmatic growth. Trace element data is being acquired to constrain the physicochemical conditions of garnet growth and evaluate REE incorporation into garnet.

Reference: Sokół, K. et al., 2018. Lithos 320-321, 172-191.

Burko is a nephelinitic volcano in the Gregory Rift of the East African Rift System (EARS), situated in northern Tanzania. The rocks are olivine-free and phonolitic nephelinites, deposited as tuffs, agglomerates and lavas that frequently contain plutonic inclusions. Based on geochemical data, a carbonatite-metasomatized mantle source has been assumed for these rocks (Mana et al., 2015).

We present a detailed mineralogical and petrological study of the variably evolved Burko rocks (whole-rock Mg numbers <50), which contain either nepheline + Fe-Ti oxide + perovskite + diopsidic pyroxene or nepheline + Fe-Ti garnet + titanite + hedenbergitic pyroxene ± alkali feldspar assemblages. Such an evolution of relatively oxidized and strongly SiO₂-undersaturated alkaline magmas towards peralkaline compositions may be a common process and is probably controlled by T-a_SiO2-f_O2 changes. Based on a comparison with spatially associated nephelinitic volcanos like Sadiman and Ol Doinyo Lengai, we discuss similarities and differences in their genesis.

Mana, S., Furman, T., Turrin, B. D., Feigenson, M. D., and Swisher, C. C., III, 2015, Magmatic activity across the East African North Tanzanian Divergence Zone: Journal of the Geological Society, v. 172, no. 3, p. 368-389.

The Motzfeldt Centre forms part of the Igaliko Complex: one of the major complexes of the Mesoproterozoic Gardar Igneous Province of Southern Greenland. This syenite hosts a Ta-Nb-Rare Earth Element (REE)-Zr alkaline-silicate roof zone, containing several metals classed as “critical” to the economy by the EU.

This study carries out detailed mineralogical, geochemical, and microtextural analysis of REE-enriched syenite variants from Motzfeldt using BSE-SEM imaging, EPMA, WDS mapping, and RAMAN spectroscopy. These data provide evidence that an aggressive, magmatically derived, F-rich fluid (F₁) altered primary magmatic pyrochlore (P₀), replacing it with mineralogically heterogeneous pseudomorphs formed of secondary pyrochlore (P₁) and several alteration phases. Also found also encrusted on the surface of P₁, these intergrown secondary phases are formed of elements lost from P₀ during alteration including Nb, REEs, F, Ca, Zr. In a second hydrothermal event (F₂), these crusts are “scrubbed” from the surface of P₁, dissolving into and enriching that fluid (F₂) in the elements scavenged from those minerals. The escape structures formed by the fluid F₂ as it exits the system are breccia pipes, cemented by a rock mineralogically reminiscent of carbonatite. Previously interpretations were that these structures were entirely magmatic, but our findings indicate these structures are late-stage hydrothermal in origin. This may be a novel mechanism by which carbonatite-type rocks are formed.

These processes display how early intensive hydrothermal events can prime an ore body for further alteration, through conversion of refractory primary phases into secondary phases more vulnerable to hydrothermal attack.

Alkaline igneous rocks are known to host a variety of rare metal deposits, including HFSEs and REEs. The Iivaara alkaline complex (Finland) and the surrounding fenite aureole show Ti-dominated enrichment of HFSEs carried by titanite and apatite. Mineralogy and textural observation indicate a shallow intrusion level, fast cooling, and steep temperature gradients, as well as expulsion of different fluids. So far, the roles of different fluids in rare metal enrichment in such systems have not been fully understood. New results of a fluid inclusion (FI) study including FI petrography, microthermometry, phase identification using Raman spectroscopy, and quantification of elements by LA-ICP-MS reveal the fluid evolution in the Iivaara alkaline complex. Three stages can be distinguished: magmatic fluid, post-magmatic fluid, and late aqueous fluid. Magmatic fluid is characterized by relatively high salinity, with a dominance of methane in the vapor phase. This fluid type is responsible for the fenitization process as well as transporting some important elements and metals like HFSEs and REEs. The post-magmatic fluid is characterized by relatively low salinity with very low to no methane concentration in the vapor phase. This fluid is responsible for recrystallization of some minerals, especially apatite and the formation of cancrinite as a replacement mineral and as a vein. And the last fluid is an aqueous fluid which is very low in salinity, interpreted as meteoric water influx at the very late stage.

The advancement of CCS-techniques is a significant tool to mitigate climate change and achieve net zero emissions. On European Level, the CCS-Directive (2009/31/EG) provides for a legal framework for, i.a., exploration and storage permits for storage sites, monitoring during and after the operational phase, requirements for closure and transfer of responsibility. The member states and associated countries have implemented these rules into national legislation. This contribution aims to, firstly, provide an overview over the regulatory framework in Europe and exemplary member states. It seeks to, secondly, outline first practical experiences from individual approval processes and to, thirdly, draw conclusions for further implementation. In this part, the focus will be on the evolving legal framework in Germany, i.p. the necessary legislative steps and possible accelerating tools.

Wintershall Dea is actively involved in developing CCS-solutions: The first Carbon Storage Project “Greensand” marks a milestone, demonstrating how CCS can move across borders through an international infrastructure that connects emissions sources with storage capacities. In the first quarter of 2023, the leading consortium partners INEOS and Wintershall Dea received the storage license from the Danish authorities and concluded the pilot phase with a first injection in the world’s first cross-border, offshore CO₂ storage project. Wintershall Dea holds or has a applied for further storage licenses in Norway and the Netherlands. This allows to tackle the procedural law issues targeted in this contribution from a practical angle.

CCS has been identified as a key element for limiting global warming. The adoption of the EU Green Deal and other European regulation have made carbon capture and storage technologies an important part of the EU decarbonisation effort.

The technology has been established in a different contexts, but CCS is not yet a routine industry application and it requires upscaling, if subsurface storing of the hard-to-abate emissions and later on Carbon dioxide from DAC and BE are to make a difference in the emerging climate crisis.

Several studies assessing storage potential in Europe have been conducted identifying large potential storage volumes, while the decision-making process regarding the application of CCS is still ongoing in many countries.

Regardless of the outcome, for CCS to become a valid option in 2030, exploration has to start now, as thorough exploration and compiling nationwide portfolio of potential sites will take several years.

In this presentation, a possible route through the site development process is delinated, covering all aspects of safe and permanent CO2 injection from exploration execution to field development. Risk assessment and mitigation play a crucial role in this framework. In addition, project-specific parameters like reservoir parameters, drill sites and well paths and in addition to absolute storage volume, the storage capacity over time are discussed, providing key input for a comprehensive analysis leading to a balanced portfolio.

A systematic assessment of potential sites is the basis for selecting the optimal locations, constructing efficiently dimensioned plants and establishing a process of maximum safety.

The storage of CO₂ in deeply buried geological formations provides an important contribution to mitigate residual emissions from heavy industry in order to limit global warming below 2 °C. Robust geological models and storage capacity estimations are crucial for the successful planning and implementation of long-term storage projects. This study focuses on the CO₂ storage potential of the Middle Buntsandstein within the Exclusive Economic Zone (EEZ) of the German North Sea. We mapped a total of 69 potential storage sites based on existing 3D models, seismic data and 39 exploration wells. Static CO₂ volumes are calculated for each structure using a Monte-Carlo-Simulation with 10.000 iterations to account for uncertainties. All potential reservoirs are evaluated based on their volume, burial depth, top seal integrity (thickness, faults) and trap type (salt-pillow and -domes, fault, stratigraphic and combined types). The best storage conditions are associated with salt-controlled anticlines on the “West Schleswig Block” with moderate burial depths, large volumes, and limited lateral flow barriers. Poor conditions are encountered in small, deeply buried (down to 7500 m), and structurally complex parts of the Horn- and Central Grabens. We identified 39 potentially technical feasible storage sites with burial depths above 4500 meters and suitable reservoir volumes (P50 confidence level above 5 Mt CO₂). The estimated total static storage capacity ranges between P90 =948 Mt, P50 = 2695 Mt and P10 =5794 Mt. This comprehensive overview about the static CO₂ storage capacities highlights the most prolific reservoirs and indicates locations for further exploration.

The Namaqua Metamorphic Complex (NMC) forms a basement unit of the Grenvillian-Kibaran collisional orogen in southern Namibia and South Africa. The Aus Crystalline Complex is a terrane within the NMC and consists, predominantly, of gneisses, granites, metavolcanites, and metasediments. The objective of our study is to generate new knowledge about crustal evolution during the Kibaran orogeny using age dating and whole rock geochemistry of various basement units of the crystalline complex around Aus.

Outcropping basement rocks were Aampled in the Namib Desert, southwestern Namibia, east of the coastal town of Lüderitz, within a 20 km radius around Aus. Rock types encountered included granulites, gneisses, charnockites, granites, and pegmatites. Geochemical and geochronological analyses were performed to gain information on the timing of crystallisation and crust production processes, using U-Pb dating on magmatic zircons with LA-ICP-MS. Analysed zircon grains are often complex, U-Pb ages range from 1700 Ma to c. 700 Ma. The oldest rock is a charnockite showing an age of intrusion of c. 1700 Ma, which represents a Palaeoproterozoic part of the cratonic basement. U-Pb zircon ages of the gneisses point to protolith ages of c. 1155 Ma – 1145 Ma. This coincides with a major tectono-magmatic event in the NMC, which occurred in a time span of c. 1190 - 980 Ma. Such processes led to the amalgamation of the supercontinent Rodinia in late Mesoproterozoic time. A younger suite of granitoids (c. 700 Ma) is most probably related to Rodinia dispersal.

The Bromacker Project (https://bromacker.de/) investigates the paleoecology of the Early Permian vertebrate “Ursaurier” lagerstätte of the same name in the red beds of the Tambach Formation, Thuringia. Its geologic-paleontologic subproject aims to contribute key paleoenvironmental parameters such as temperature variation, precipitation estimates, paleoelevation, soil hydrology, detailed paleogeography, and depositional environments, based on sedimentology, paleoichnology, facies analysis, petrography, geochemistry, and precise depositional ages.

Two new deep research boreholes will complement information from shallow legacy boreholes and outcrops near the Bromacker excavation site. Forschungsbohrung (Fb) Altenbergen 01/2022, 3 km to the north, cored 250 m of the Tambach Formation and terminated in conglomerates (Bielstein Member) after having cored the topmost Finsterbergen Conglomerate Member and the Tambach Sandstone Member. Contacts between members in core are gradual but differences pronounced: The basal Bielstein Member is dominated by well-rounded intermediate volcanic clasts, in contrast to felsic volcanic clasts described from outcrops. Fossiliferous pelitic-arenaceous redbeds of the overlying Tambach Sandstone Member show all indications of floodplain facies, including mudcracks, variable burrowing, root horizons, calcareous paleosol concretions, climbing ripples, and common laminated siltstones. Conglomerates of the topmost Finsterbergen Member consist of subangular plutonic, metamorphic and (sub-)volcanic clasts. Several newly documented thin felsic tuffs may be datable. Geophysical logs suggest rhythmic deposition suitable for cyclostratigraphic analysis. Fb Gallberg 01/2023, located 2 km south of the Bromacker excavation site, will complement Fb Altenbergen. Information from both boreholes will contribute to a robust sedimentologic-stratigraphic frame for paleogeographic-paleoecologic analyses. A substantial education and outreach program accompanies excavation, drilling and core analysis.

The Central European Basin is an intracontinental basin filled with Permian to Quaternary sediments. The southeastern basin rim, an area roughly covering the southern part of Saxony-Anhalt and eastern Thuringia (Central Germany), is characterized by complex facies distributions with a stratigraphic gap of approximately 200 Ma, where Cenozoic sediments unconformably cover the lower Triassic strata. The sedimentary rocks include several hundreds of meters thick evaporites, sandstone, shale, and carbonates of Permian to Late Triassic age, covered by unconsolidated sediments.

Various tectonic structures like NW-SE trending uplifted basement e. g. the Harz and Kyffhäuser Mountains and narrow fault zones where some abruptly ending along-strike; subordinated NE-SW trending faults sub-parallel to the Permian basin rim and salt structures characterise the area. These structures evolved during several phases of extension and contraction during Mesozoic to Cenozoic times. Due to the stratigraphic gap of the upper Mesozoic, tectonic and halokinetic processes can be well correlated with the wider Central European Basin and earlier structures. Local halokinetic processes and subrosion of evaporites indicated by the distribution of Tertiary deposits as well as variation of the thickness of evaporites influencing the geomorphology at the South-Eastern Harz Foreland until today.

Here, we used 3D modelling techniques and compiled data from drilling, seismic reflection profiles and historic mining surveys to visualize the temporal - spatial distribution and structural configuration of the South-Eastern Harz Foreland. This model will be used to unravel kinematic processes over geologic times, which will be a basis for future underground planning efforts.

During a mapping-project in 2011, evidence of a sediment occurrence was discovered within a morphological depression of a gneiss area in the Osterzgebirge near the village of Börnersdorf (Saxony). Marls and partly sandstones, presumably Cretaceous in age, were described by means of drill cores from the 1960s.

The short wells drilled around 2010 supported this assumption. Results of several geophysical investigations displayed a basin structure with 600 m in diameter and up to 350 m in depth. Paleontological data of the examined marls pointed to a Coniacian age of the sediments that infill the structure. Until recently, the structure was interpreted as either a tectonic pull apart basin or a maar structure.

In 2021, first investigations for a new railway track from Dresden to Prague were carried out.

In order to realize this project, a tunnel of about 30 km in length crossing the Erzgebirge is planned. Therefore, several new wells were sunk in the area of investigation. One of the cores near Börnersdorf provided a breccia of grey marl and black silt pebbles and cobbles. As there is not a tectonic contact between the breccia and the surrounding gneiss, the sediment is interpreted as a collapse breccia. New paleontological examinations proof a late Turonian to middle Coniacian age of the marls.

The Danakhil depression is a regional structure in Ethiopia that extents over about 450 km from the Gulf of Djibouti to the NW approximately parallel to the Red Sea coast. It has a maximum width of about 75 km. On surface the SE part of the depression is dominated by recent volcanic rocks with only local windows to the sedimentary rocks below. The part NW of the Erte Ale volcanic structure at an elevation lower than 100 m below sea level is dominated by recent evaporite rocks and alluvial fan deposits with only few recent volcanic structures and is the focus for this contribution.

Although already since the early twentieth century potash and sulphur were mined from the region providing an incentive for investigations, the first regional geologic studies were published only in the 1970’s. These studies were based on interpretation of aerial photographs with minor ground checks. Although recently some further papers about the region have been published, the wealth of information about the regional geology that has been obtained from potash exploration that started in 2008 is hidden in publically accessible technical reports, not usually in focus of geo-scientists. The exploration targeted a neogene or quarternary potash-bearing evaporite sequence within the NW part of the depression. In this contribution we want to present some consequences for the understanding of the regional geology that were developed as a by-product of more than 10 years of potash exploration in the Danakhil depression.

A coordinated and effective use of the subsurface requires in-depth knowledge and easily accessible and uniformly described data. The 2022 Action Plan supports the securing of future investments in the subsurface through the provision of structured and harmonized digital geological data.

The efficient use of geological data in Switzerland is hindered by these factors: 1) Existing data sets are neither completely available in digital form, nor comprehensive, nor harmonized; 2) Uniform access to federal and cantonal data is lacking; 3) Information systems for 3D visualization and analysis of geological and non-specialist (geo-referenced) data are being developed.

In the future, the main benefit of geoinformation will be generated from the improvement of efficiency in the processing of existing data and from increased data quality, not from new products. The action plan starts here and defines these fields of action: Standards, Harmonization, Production and Access. In doing so, it is aligned with various strategies and policy areas. The digitalization called for in the action plan will facilitate the exchange and use of geological data and improve their availability. A coordinated approach with the most important national data owners is in focus, as is the use of new technologies.

The success of the action plan will be measured after completion by the state of digitization of analog archives as well as the achieved standardization, harmonization and completion of geological data and models throughout Switzerland.

The presentation will highlight the background, scope, ongoing implementation and future of the action plan using practical examples.

Der Beginn des systematischen, wissenschaftlichen Sammelns von Mineralen und Fossilien in Berlin ist eng verknüpft mit der Gründung der Berliner Bergakademie durch Friedrich II. Ab 1801 erhielt diese Sammlung die Bezeichnung „Königliches Mineralienkabinett“.

Mit der Gründung der Königlich Preußischen Geologischen Landesanstalt (KPGLA) 1873, der Integration der Bergakademie in jene wurde der systematische Aufbau des Probenarchivs - insbesondere in Zusammenhang mit der geologischen Kartierung Preußens und der Lagerstättenerkundung im In- und Ausland, inkl. der deutschen Kolonien forciert und es begann der Aufbau eines Geologischen Landesmuseums in Berlin. Ihrer Bestimmung nach dienten die Sammlungen in erster Linie als Archiv für das Belegmaterial aus der geologischen Kartierung und der wissenschaftlichen Erkundungsarbeiten. Der geschätzte Gesamtbestand umfasste 1939 ca. 1200 doppelseitige Schränke.

Nach erheblichen Verlusten des Sammlungsbestandes im 2. Weltkrieg, und der Abgabe von großen Teilen der im damaligen Ostteil Berlins befindlichen Sammlungen an das benachbarte Museum für Naturkunde durch die Staatliche Geologische Kommission der DDR hatte sich der Umfang der Sammlungen etwa halbiert. In den Jahren bis 1990 wuchs der Bestand wieder beträchtlich, insbesondere im Rahmen der intensiven und extensiven Rohstofferkundungen im Zentralen Geologischen Institut der DDR (ZGI).

Bei der Übernahme der Sammlungen durch die BGR 1990 lag die Anzahl der Schränke bei ca. 800. Seit 1996 sind die historischen geowissenschaftlichen Sammlungen sehr repräsentativ in Dienstbereich Berlin-Spandau in den ehemaligen Stallungen eines preußischen Kasernenkomplexes untergebracht. Die Digitalisierung und virtuelle Nutzbarmachung des umfangreichen Sammlungsbestandes für Wissenschaft und Öffentlichkeit stehen seither im Fokus der Arbeiten. Stand 2023 sind ca. 65 % des Bestandes online recherchierbar.

The search for saline water springs started in the area of Mecklenburg-Western Pomerania several hundreds of years ago. First drillings to find coals seams were reported from the end of the 18^th century. Mining for brown coal lasted from 1817 until 1960. Three mines produced between 1900 and 1926 potash and rock salt. First oil exploration wells were drilled in the 1920/30s without success. Numerous deep wells drilled between 1950 and 1990 reaching depths up to 8,009 m and about 3,600 seismic lines enabled the detection of several oil deposits. The huge amount of subsurface data allowed to find geothermal resources in the 1980s and is still the base for new scientific investigations and to develop projects of underground uses.

The archive of the Geological Survey of Mecklenburg-Western Pomerania comprises lithology data from 700 deep wells. More than 2,250 well logs exist, most of them are SP and GR logs. 70,000 m of cores from 400 wells document rocks from different eras beginning with the Mesoproterozoic basement of Baltica, covering the Caledonian deformed Ordovician on Rügen and the Devonian to Carboniferous strata of the Variscan foreland as well as the volcanics and sediments filling the North German Basin since the Permian. More than 11,000 rock samples and c. 26,000 thin sections used for petrographic descriptions are preserved. Countless analogue data gained from petrophysical and geochemical analyses still have to be digitized to fulfill the requirements of the Geological Data Act (GeolDG), especially for making geological data available for the public.

The Geological Archives (geoarchives) of State Geological Surveys have an over 150 years old tradition. Since the first geological surveys were funded in the early 1870s State Geological Surveys collected, inventoried and provided samples, maps and reports from geoscientific exploration and analysis. As a result, geoarchives comprise a huge store of knowledge for geologic surveying and further applied questions. Thereby, work tasks in geoarchives have special focusses: (1) In contrast to classical steady-state archives, the inventory must be permanently available and usable for geological surveys and economic companies. (2) All inventory can accurately be georeferenced, i.e. even documents must be assumed to contain geoinformation. (3) Geoarchives contain material, e.g. rock samples, drill cores on the one hand and printed reports, maps and paper rolls on the other hand, with a broad spectrum of requirements on the storage conditions. With the commencement of the Geological Data Act (GeolDG) these tasks were recently expanded to aspects of digitalization and digital provision of geoarchive inventory. Therefore, all material must be completely checked, categorized and indexed with keywords to make the inventory FAIR (findable, accessible, interoperable and reusable). In our contribution we present the historical evolution and relevance of the geoarchive of the Landesamt für Geologie und Bergwesen Sachsen-Anhalt (LAGB) and explain our recent concepts against the background of the GeolDG.

Im Rahmen der geologischen Landesaufnahme werden in Hessen, wie in allen anderen Bundesländern auch, seit weit über 100 Jahren wertvolle Gesteinsproben (Bohrkerne, Handstücke, Fossilien, Mineralien) gesammelt, beschrieben, analysiert und archiviert. So liegen aktuell alleine für das Gebiet Hessens über 45.000 Handstücke, mehrere 1000 Makrofossilien und ca. 700 Bohrungen vor. Der Öffentlichkeit bzw. interessierten Dritten stehen diese Archivalien zwar grundsätzlich zur Verfügung, jedoch stellen die bisher gegebenen Zugangsmöglichkeiten kein niederschwelliges Angebot dar. Im Zuge der digitalen Transformation sollen deshalb auch diese "unüblichen Informationsträger" digitalisiert und als 3D-Objekte funktional, performant und um weiterführende Informationen "angereichert" über das Internet abrufbar sein. Hierzu wird das Hesssische Landesamt für Naturschutz, Umwelt und Geologie (HLNUG) seit 2022 durch das Hessische Ministerium für Digitale Strategie und Entwicklung gefördert. Die Projektarbeiten adressieren sowohl die Erstellung von geologischen 3D-Objekten wie auch deren Visualisierung bzw. Veröffentlichung im Internet. Im Rahmen des Vortrages werden die bisherigen Bemühungen, der nunmehr präferierte methodische Ansatz und erste serienreife Ergebnisse vorgestellt. Dabei handelt es sich sowohl um Handstücke wie auch Bohrkerne. Auch wird das Konzept zur Veröffentlichung der erarbeiteten 3D-Objekte im Internet unter Berücksichtigung diverser Anwendungsfälle vorgestellt. Mit dem Vortrag möchte das HLNUG potenzielle Mitstreiter erreichen, sei es im Kreise der Staatlichen Geologischen Dienste oder auch Universitäten, wo die Digitalisierung der Lehre im Bereich der Grundlagenvermittlung auch und besonders bei den Geowissenschaften eine große Herausforderung darstellt.

The drive towards net-zero emissions as per the Paris 2015 agreement has resulted in significant efforts to develop sustainable energy resources. In order to change the current energy system, alternative resources need to replace wood, coal, oil and gas. One of the recent new findings in the Geo-Energy sector is natural hydrogen which can be found in many places around the globe as seeps.

Reasons for the lack of interest in hydrogen exploration so far are multi-fold, like nobody considered natural hydrogen as a viable option, hydrogen cannot be detected easily, other energy resources were available in large quantities and at low cost and more. However, many indications point towards a major clean energy resource of the future considering that in the last few years some 300 seeps have been reported. One of the most famous ones is the eternal fires of Chimaera in Turkey, know to burn since more than 2500 years. In the meantime, the first hydrogen exploration companies have formed and even a first long-term production test is ongoing.

Natural (white) hydrogen was until now not considered in the energy transition. If further developments turn out to be successful, this may result in another unexpected game changer in the energy sector similar to coal replacing peat in 1880. However, the question remains, what such a potential new energy opportunity could look like as part of the future energy mix. This talk will highlight the current status and potential ways forward on this new energy resource.

The results of the application of the mobile direct-prospecting technology of frequency-resonance processing and interpretation of satellite images and photographs in large areas and local areas of hydrogen degassing in German various regions are presented. Experimental reconnaissance studies were carried out to study the features of the deep structure of hydrogen-degassing areas.

Instrumental measurements confirmed the presence of large zones of hydrogen degassing in the areas of basalt volcanoes in Bavaria. Signals at the frequencies of hydrogen, basalts and healing water were recorded at the sites performed for the hydrogen migration. Measurements recorded the facts of hydrogen migration into the atmosphere. When scanning the cross-section, responses from hydrogen are recorded from the upper edges of basaltic volcanoes to their roots. Signals at hydrogen frequencies were also recorded from limestones, dolomites, and marls overlying the basalts from above (including at shallow depths). Experimental studies have also shown that siliceous rocks can be a good seal for hydrogen. There is no hydrogen migration into the atmosphere within basalts, overlapped by siliceous rocks. The obtained results of experimental work are also additional evidence in favour of the "volcanic" model of the formation of various structural elements and the external appearance of the Earth, as well as deposits of combustible and ore minerals (including hydrogen and water).

The use of mobile and low-cost technology will significantly speed up the exploration process for hydrogen, as well as reduce the financial costs for its implementation.

Keywords. Hydrogen,basalts, limestones,healing water, abiogenic genesis,volcano,direct searching,remote sensing data

The activation of methanogenic Archaea in the context of subsurface hydrogen storage may lead to permanent hydrogen conversion to methane. The objective of this proof-of-concept study is to experimentally investigate these activities, and it is focused on reservoir analogues from the Cretaceous and Triassic periods. These analogues have been selected based on their varying porosities, which range from 8% to 24%. Methanothermococcus thermolithotrophicus was used as the model organism due to its relatively high activity and growth rate. The microbial activities in various water-saturated reservoir rocks with either similar bulk or pore volumes, as well as inoculated media containing sand particles and rock fragments, were experimentally studied and compared to values obtained in bulk solutions. Measured activities in the water-saturated rock specimens with identical bulk volumes varied between 0.17 and 1.22 mM H₂ /h largely correlating with the pore volume. Furthermore, the results indicated that activities in the water-filled pore space of the respective rocks were higher by a factor of 8-10 compared to activities in bulk solutions. This observation, in conjunction with the measured activities in inoculated media containing sand particles and rock fragments, as well as in rocks with similar pore volume, supported the notion that the surface area available for microbial colonization is another factor in controlling activity when the amount of substance is held constant. Additionally, the study suggests that methanogenic activities used to quantify hydrogen conversion in reservoirs must potentially be revisited because they are typically measured on bulk solution rather than within intact rocks.

Hydrogen (H₂) was injected into a shallow aquifer at the TestUM field site (close to Wittstock, Brandenburg, Germany) in order to simulate a H₂ gas leakage scenario. The resulting biogeochemical processes were monitored in space and time by analyses of stables hydrogen isotopes, groundwater microbial community composition and geochemical parameters in two monitoring wells (D04, D06) close to the injection wells, and a reference well (D11) not directly affected by the injected H₂. During the injection, initial shifts in the isotope signature of H₂ were observed, probably caused by dissolution of H₂ in the water phase and the migration of the gas phase through pores and channels in the aquifer. After the injection, H₂ concentrations in D04 and D06 decreased within less than 80 days from maximal 850 µmol/L below the detection limit, accompanied by an equilibrium isotope exchange with water leading to a strong isotopic depletion of H₂, a reaction typically catalyzed by the H₂-cleaving enzyme hydrogenase. Microbial H₂ oxidation and subsequent growth of hydrogenotrophic prokaryotes was further indicated by temporally increasing abundances of putative H₂-oxidizing sulfate reducers, acetogens, nitrate reducers and aerobes, accompanied by nitrate disappearance and transiently increasing acetate concentrations. In summary, the results confirm our expectation that H₂, being an excellent energy source for many microorganisms, is quickly microbiologically consumed in an aquifer after a leakage.

Higher temperatures and increasing droughts are likely to lead to a reduction in available water resources in the Berlin-Brandenburg region. Concurrently, there is an increasing demand for water due to the population and economic development in the region. This results in serious water management challenges. To mitigate this water scarcity, in 2021, work began on setting up a coordinated joint groundwater management system based on a transboundary groundwater flow model for the capital region (approx. 2800 km², from which Berlin covers 892 km²). The central component is the modelling of the reciprocal effects of the groundwater abstraction by the water suppliers in the region with regard to sustainable management of the common groundwater body. In the first step, the hydrogeological structural model (HSM) for the region is created. In doing so, up-to-date geological sections from the Berlin and Brandenburg Geological Surveys as well as stratigraphical settings from existing calibrated groundwater models are brought together. The groundwater models of the Berliner Wasserbetriebe are also incorporated in this process. These models have been developed since approximately 20 years and are regularly updated. They are used both in approval processes and in daily operation. In the second step, the HSM is converted into a flow model. This flow model is calibrated and compared with the existing models. In the end, a model for the entire capital region will be available for the first time. At the conference, the current status of the project will be presented and the challenges will be highlighted.

In vielen Regionen zeigt die Auswertung der Grundwasserstandsentwicklung, dass ein Rückgang der Grundwasserstände zu verzeichnen ist (z.B. NLWKN, 2020). Jedoch steigen gleichzeitig der Wasserbedarf und die Anzahl der Wasserrechtsanträge, vor allem in landwirtschaftlich geprägten Regionen. Vor diesem Hintergrund, wird auch in der Forderung des Deutschen Vereins des Gas- und Wasserfaches e.V. (DVGW Wasser-Impuls: Zukunftsbilder 2030 bis 2100) beschrieben, dass bei der Entwicklung und Umsetzung langfristiger Zukunftskonzepte im Bereich Wassermanagement digitale Lösungen eine erhebliche Unterstützung sein sollen. Dazu werden u.a. Prognose- und Managementmodelle für ganze Einzugsgebiete vorgeschlagen.

In diesem Sinne wurde für den Landkreis Vechta ein Grundwassermodell in FEFLOW erstellt, um bei der Bearbeitung von Wasserrechtsanträgen zu unterstützen (Flechtner et al., 2022). Grundwassermodelle sind jedoch oft teuer und nur von Experten nutzbar. Das bedeutet, dass die Modellierung von weiteren Szenarien (z.B. erhöhte Pumpraten oder zusätzliche Brunnenstandorte), an denen der Kunde oder die Behörde interessiert ist, sprich die Weiterverwendung des Modells, meist von externen Experten durchgeführt werden muss. Um der Behörde ein wie vom DVGW beschriebenes Prognose- und Managementmodell bereitzustellen, welches von dieser selbstständig im täglichen Geschäft verwendet werden kann, wurde von DHI WASY das Grundwassermodell zu einem interaktiven Modell erweitert. Dieses kann die Behörde in Ihrem täglichen Geschäft über eine Benutzeroberfläche selbst, mit wenigen, einfachen Arbeitsschritten, bedienen, ohne auf externe Experten angewiesen zu sein. Die Modellergebnisse der von der Behörde erstellten Szenarien werden automatisch exportiert und in einem interaktiven HTML-Format angezeigt, so dass der Kunde alle relevanten Daten und Ergebnisse schnell und auf einen Blick für weitere Entscheidungen zur Hand hat.

Climate projections indicate that extreme weather events have increased in frequency and intensity in the past and will affect sensitive Germany in the near future. Our study site, the catchment of the lower Spree, is located in Brandenburg. The region is affected by water stress showing a water deficit of 80 Mio. m³ on an area of 3500 km² with many competing water users. Our goal is to investigate the impact of shifts in climate, land use and vegetation on recharge and available groundwater resources. In four different catchments with different characteristics we monitor groundwater und lake levels, stream discharge, and depth dependent soil moisture. Isotopic composition of precipitation, groundwater, and surface water is investigated to calculate water fluxes between different compartments. Electrical conductivity down to a depth of 200m below surface is recorded. Measured NaCl concentrations reach up to 10 – 15 g/kg. Employing the hydrological model SWAT evapotranspiration, discharge and soil moisture are calibrated to calculate long-term groundwater ranges pattern, which ranges in average at 77 mm/a. The M-K test shows decreasing recharge from May to August, an increase from December to February, and almost no change from September to November leading to an overall decreasing trend over the last 20 years. We are planning to derive concepts for areas with highest economic or ecological value derived from socio-economic analyses for the implementation of artificial recharge using greywater, treated waste water or storm water to replenish the groundwater deficit and to retain uplift of the saline groundwater water.

We explore the effects of a changing climate on groundwater dynamics based on thermo-hydraulic simulations to reconstruct the temperature and pressure below the State of Brandenburg between 1950 and 2010. In this time period, observations point to ~1°C surface temperature warming, large annual fluctuations in groundwater recharge, and periods of high groundwater abstraction volume — all leading to water stress conditions. Our input structural model integrates Permian to Cenozoic sedimentary units with essential geological features controlling the regional groundwater flow, including salt structures, permeable glacial valleys, and aquitard discontinuities. We use a grid-based hydrologic model to derive inflow and outflow rates across the top boundary of the subsurface model. Simulation outputs are verified against data from available observation wells.

The simulation results demonstrate that the regional flow pattern in the deep aquifers (>1 km deep) is mainly controlled by the basin geometry, while shallow groundwater dynamics is heavily influenced by high-frequency climate forcing. Seasonal fluctuations in groundwater level are observed in areas of shallow (<10 m) water table, with the highest levels corresponding to months of greater recharge rates. Where the water table is deeper, it responds to precipitation pulses with a delay of several months. Seasonal groundwater heating and cooling is limited to the first 10–30 meters, except within glacial valleys where high hydraulic gradients and permeabilities lead to a deepening of the advective heat transport. In addition, we identified periods and regions of significant groundwater abstraction and sustained groundwater warming over the entire simulation period within urban areas.

Water stress is increasing in Northeast Germany due to climate change. New approaches for water management are needed to mitigate the impacts on the water system and water users. Therefore, our study deals with the development of a web-based toolbox for subsurface water storage with focus on the lower catchment of the river Spree in the federal state of Brandenburg.

Our approach is based on a systematic combination of site selection criteria and spatial data on land use, soil, groundwater and potential water sources. This will provide relevant information for the preliminary planning of managed groundwater recharge measures by authorities and water suppliers. Considering surpluses from runoff and surface waters, also caused by extreme weather events, suitable locations for surface-induced recharge will be identified.

Supported by additional modelling-based indications for implementation, efficiency and costs, as well as simplified site selection through a query system, the toolbox will offer an initial knowledge for such planning considerations.

The continental subsurface contains approximately 12 – 20% of Earth’s biomass. In deep rock environments this biomass dwells in aqueous spaces, fractures and pores of the rock, either attached in biofilms or free-living in the fluids. Meta-analyses have suggested a core deep biosphere microbiome from pre-collected data but face issues such as difference in sampling procedures, DNA extraction methods, negative control protocols, sequencing primers etc., which may introduce false variation. Addressing this issue and striving for consistent methodology, 7 sites of the Finnish Fennoscandian Shield was studied between 2009 – 2021 ranging in depth from 100 to 2300 m. Some of the sites have deep groundwater with more than 50 Ma residence times, whereas in other places the groundwater is considerably younger. All microbiomes contained bacteria, archaea and fungi, and the microbial community composition differed greatly between sites indicating that rock type and hydrogeochemistry play a great role in moulding the communities. Chemoheterotrophy was the universally dominant predicted metabolic strategy. The bacterial numbers in the groundwater were between < 1 to more than 5 x 10⁶ 16S rRNA gene copies mL^-1 but did not necessarily reflect sampling depth, but rather the concentration of DOC and DIC. In addition, dormant microbial communities activated within hours after introduction of CO₂ or methane. Finally, groundwater monitored at one site for 10 years showed that the microbial communities did dot remain static but varied in size (up to 100-fold) and composition over time in a cyclic manner, interchanging between mainly two distinct community compositions.

Nano-magnetite is a potential archive for biosignatures of iron-cycling microorganisms in hydrothermal systems, which are widely considered to be among the most ancient microbial habitats on Earth. Sulfidic diagenesis driven by hydrothermal fluids and microbial sulfur cycling potentially causes the rapid transformation of magnetite to iron sulfide minerals. Thus, identifying nano-magnetite and its transformation products in hydrothermal sulfide deposits is crucial for reconstructing iron- and sulfur-cycling microbial life in deep time. However, the identity and characteristics of iron sulfide minerals resulting from nano-magnetite sulfidation at hydrothermal conditions have previously not been constrained. Here we present experimental data on sulfidation reactions of synthetic and biogenic nano-magnetite at physical and chemical conditions relevant to microbial habitats in hydrothermal systems on early Earth (<121°C, anoxic, sulfidic). We characterize the resulting precipitates with analytical imaging techniques, mineralogical methods, and geochemical approaches (e.g., SEM-EDS, µXRD, Raman spectroscopy, sequential Fe extraction). Our results demonstrate a potential taphonomic bias against nano-magnetite in sulfidic hydrothermal habitats and suggest that biosignature records of iron- and sulfur-cycling microorganisms in ancient hydrothermal sulfides are affected by diagenetic fluid-mineral interactions.

Lake Towuti, Indonesia is a stratified ferruginous (iron-rich, sulfate-poor) system whose deep basin experienced dynamic changes in trophic and redox conditions since the Middle Pleistocene. As wet and dry periods alternated and sediment accumulated, microbial life sustained by metals and organic substrates became entombed in the subsurface. A 1 Ma stratigraphic archive retrieved by the International Continental scientific Drilling Program (ICDP) was sampled aseptically on site for microbiology analysis. Through taxonomic and functional analyses (16S rRNA amplicons, metagenomics), the BioMetArchive project aims at the first comprehensive characterization of the lacustrine subsurface biosphere in terms of diversity, abundance and metabolic functions.

Metagenomic data combined with high resolution cell counts and pore water geochemistry allowed to characterize the distribution of microorganisms throughout the core and to identify which microbial taxa and metabolic features are involved in the major biogeochemical cycles and organic matter remineralization during sediment burial. Results show a drastic decrease in the cell counts (from 10⁹ to 10⁴) as electron acceptors in the pore water chemistry become depleted within the upper 5 m of the sediment. Results of taxonomic and metagenomic analyses indicate that the sediment ferruginous conditions predominantly select for fermentative Bathyarchaeia. Metabolic features attributed to this entirely uncultivated phylum explaining their selective growth were indicative of sulfur transformations, organic matter fermentation and homoacetogenic dark carbon fixation. Thus, Lake Towuti shelters a deep biosphere displaying similarities to early life’s processes in ferruginous systems, which provides a direct link between cryptic sulfur cycling and redox conservative fermentations.

Seismic activity and consistently high CO₂ fluxes make the Eger Rift in Western Bohemia (CZ) a rare subsurface ecosystem and scientifically relevant location to study microbial behavior and assess how geologically derived compound are used in the deep subsurface. Studying microbial life in this ecosystem provides the opportunity to investigate how high CO₂ levels and mineralogy influence microbial community composition and metabolic activity. Seismic activity in this region can also release H₂, a process which may provide the basis for primary production through methanogenic archaea and should be explored.

To assess microbial processes associated with the Eger Rift subsurface we investigated diversity, community structure and metabolic attributes of bacterial and archaeal communities in drill core sediments and groundwater samples. We also analyzed the geochemical conditions in this subsurface system and studied the physiological responses of native Eger microbial communities to high CO₂ via enrichments

Genomic analysis of sediment and water samples, covering depths between 17m and 230m, provided novel insights into a CO₂ adapted microbial community. We detected strong Cyanobacteria and Proteobacteria signatures as well as unexpected archaeal diversity in sediments, and high abundances of acidophiles and sulfate reducers in water samples. Enrichment cultures from the recovered sediments suggested subsurface populations can actively utilize CO₂ and H₂, while reconstruction and annotation of MAGs provided insights into microbial processes driven by CO₂.

Going forward our data will be used to further investigate cellular processes under high CO₂ conditions and identify pathways and biomolecules which may be of industrial and biotechnological relevance.

The redox state of the upper mantle in the Archaean through to the Proterozoic is a key parameter as it would have buffered atmospheric composition and interacted with the ocean-atmosphere system. There have been multiple approaches using geochemical proxies, such as V-Sc and redox sensitive stable isotopes (e.g. Fe) applied to mantle-derived rocks to investigate this problem. As whole rock samples are prone to overprinting (alteration, metamorphism) and as mafic rocks in particular are difficult to date, a technique using a robust U-bearing accessory mineral might allow better and more trustworthy temporal constraints to be measured. Recent work developing an oxybarometer based on S in apatite using µ-XANES has shown great promise as apatite can seamlessly incorporate reduced and oxidised S species and directly reflect the fugacity of host magmas. Nonetheless, apatite crystals in a matrix rock are prone to alteration and recrystallisation, but apatite inclusions trapped in zircon during magmatic crystallisation are robust, with the advantage that the enclosing zircon can be dated and the mantle source traced via Lu-Hf and O isotopes. To demonstrate that this approach works, we have studied 2.35 Ga TTGs and 2.13 Ga sanukitoids from the Mineiro Belt, Brazil. These rocks temporally straddle the Great Oxidation Event. Apatite inclusions in zircons from this TTG-sanukitoid transitional magmatic record reveal a change from reduced to more oxidised conditions from pre- to post-GOE. We then discuss how this approach has and can be further applied to Archaean rocks as a tracing tool for earlier oxygenation events.

The scarcity of well-preserved exposed Precambrian rocks as well as post-emplacement metamorphism and alteration hamper a detailed understanding of mantle differentiation processes on the early Earth. This issue can be overcome by powerful tools such as the short-lived isotope decay series such as ¹⁸²Hf-¹⁸²W and ¹⁴⁶Sm-¹⁴²Nd isotope systems that only record radiogenic ingrowth during the Hadean Eon.

This study focuses on high-precision measurements of ¹⁸²W/¹⁸⁴W and¹⁴²Nd/¹⁴⁴Nd isotope compositions using MC-ICP-MS ([1], [2]) of ultramafic, mafic and felsic rocks from the Singhbhum Craton (India) that range in their crystallization age from 3.5 to 1.6 Ga. Due to the susceptibility of W to secondary fluid-rock interactions, the rock samples that were chosen were initially tested for mobility of W by a comparison of W with other equally incompatible elements such as Th, Ta, U [3] that were obtained by ICP-MS with a focus on precise measurements of High Field Strength Element concentrations (<6% uncertainty). Preliminary ¹⁸²W isotope data that ranges from µ¹⁸²W= -1.6 to -0.7 (±2-3 ppm; 95% CI) shows a slight tendency to negative values that are unresolvable from the modern mantle value. This data, in combination with robust ¹⁴²Nd isotope constraints can give fresh insights into early mantle differentiation of the Singhbhum Craton and access the timescales of homogenization of the ambient mantle with late accreted material.

[1] Tusch et al. (2022), PNAS 119

[2] Hasenstab-Dübeler et al. (2022), Chem. Geo. 614

[3] König et al. (2011), Geochim. Cosmochim. Acta 75

The short-lived isotope systems ¹⁴⁶Sm-¹⁴²Nd and ¹⁸²Hf-¹⁸²W were active during the first ca. 500 Ma and 50 Ma after solar system formation. As a result of recent analytical advances, it is now possible to detect small ¹⁴²Nd-¹⁸²W variations (≤ 3ppm) within terrestrial samples providing unprecedented information on Earth’s accretion, early differentiation, as well as mantle mixing and homogenization rates.

Here, we present high precision ¹⁴²Nd/¹⁴⁴Nd and ¹⁸²W/¹⁸⁴W data for Neoarchean samples from the Yilgarn Craton, W-Australia, using previously published MC ICP-MS protocols [1,2]. We report µ¹⁴²Nd deficits as low as -4.2 ± 1.4 for 2.7 Ga mafic-ultramafic samples from the Kalgoorlie Terrane. A contemporaneous mafic-ultramafic suite from the Kambalda area displays small µ¹⁴²Nd values between +0.4 ± 1.2 to -1.5 ± 0.9 that seem to correlate positively with ε¹⁴³Nd. If interpreted to represent a differentiation model age, this event could not have happened earlier than 4.13 Ga. This suite reveals a correlation of long-lived ε¹⁴³Nd-ε¹⁷⁶Hf isotope systematics, suggestive of a pristine mantle source. We further suggest that µ¹⁸²W excesses from the Kalgoorlie and Kambalda suites (+5.3 ± 3.6 and +4.5 ± 1.6) demonstrate a missing late veneer component in the mantle source, in line with previously reported ε¹⁰⁰Ru excesses found in the same samples [3]. In conclusion, our results demonstrate that mantle-derived rocks from the Yilgarn Craton carry isotope signatures directly referring to Hadean processes.

[1] Hasenstab-Dübeler et al. (2022) Chem. Geol. 614, 121-141

[2] Tusch et al. (2019) GCA 257, 284-310

[3] Fischer-Gödde et al. (2021) Goldschmidt Abstract 4362

¹⁸²W deficits in terrestrial rocks are currently strongly debated since their origin can be ascribed to different processes. These include (1) core-mantle interaction, (2) grainy late accretion, and (3) early silicate differentiation. Mantle-derived rocks from the eastern Kaapvaal Craton yield variably negative µ¹⁸²W values that are systematically correlated with initial values of the long-lived Hf-Nd-Ce isotope systems. These have been interpreted to reflect incorporation of an early Hadean crustal restite either in the deep mantle sources of Archean mantle plumes or within the upper mantle or lower lithosphere of the Kaapvaal Craton. Interestingly, granitoids from the Kaapvaal Craton are either overlapping with the modern ¹⁸²W isotope composition or carry a strongly negative µ¹⁸²W of down to -10, overlapping with Mesoarchean diamictites from the Kaapvaal Craton. Deviation of some granitoids from the Kaapvaal ¹⁸²W-¹⁷⁶Hf and ¹⁸²W-¹⁴³Nd array are likely caused by disturbance of the whole-rock Hf-Nd data or by fluid mobility of W. Here we will further explore the ¹⁸²W isotope composition of the Paleoarchean Ngwane Gneiss suite from the Ancient Gneiss Complex (Eswatini) and TTG plutons from the Barberton Mountain Land, that reveal a time-integrated increase of initial epsHf values in magmatic zircon. Our results provide further constraints on the origin of granitoids that plot at the upper end of the µ¹⁸²W-epsHf array. We will present first 182W data produced on the NEOMA MC-ICPMS in Berlin, which have a high level of accuracy as revealed by replicate measurments from samples previously measured at University of Cologne.

Defining patterns of environmental or ecological change on different spatio-temporal scales is key to tracking and addressing present and future biodiversity changes, which is particularly important considering the rapidly changing climate scenarios. Climate change in the arctic means shrinking glaciers, drying out of peatland and carbon release, more frequent forest and peatland fires, and thawing permafrost. Alaska hosts some of the largest Boreal peatlands and forests; however, little is known about the fine-scale dynamics of these ecosystems particularly over the last millennia, which is key to making effective management decisions into the uncertain future. In this presentation, I will be presenting the results so far from an ongoing work that employs different lines of evidence (pollen, non-pollen palynomorphs, charcoal, and tephra) from two peatland sites in southern Alaska to reveal interactions between vegetation, fire and climate in the area during the last millennia, as well as the potential influence of humans and volcanic eruptions on these interactions.

The Atacama Desert is the oldest and driest non-polar desert on Earth, where salts have accumulated through atmospheric deposition over millions of years of hyperaridity. These salts can serve as an indicator to provide an understanding of the interaction between water and soil in changing environmental conditions. Therefore, four soil profiles were studied for their mineralogy, abundance of salts, and stable isotopic composition of sulfate. In all soil profiles, sulfates are the predominant salts showing a downward transition from gypsum to anhydrite accompanied by an increase in highly soluble salts and a decrease in δ³⁴S and δ¹⁸O values of sulfate. These trends are consistent with downward water infiltration during rare rain events causing salt dissolution and subsequent precipitation in the deeper soil column. This conclusion is also supported by our Rayleigh fractionation model. The presence of anhydrite at >40 cm depth is attributed to their association with nitrate and chloride salts, which reduces water activity during sulfate precipitation and thus stimulates anhydrite formation. Along the elevation transect, the total salt inventories of the individual profiles show a tendency for nitrate and chloride concentrations to decrease with elevation. This observation, together with the stable isotopes of sulfate, suggests a fog-independent source and points to the remobilization of soluble salts by enhanced erosion of the hillslopes. These findings are essential for understanding pedogenetic processes and long-term regional habitability of hyperarid environments.

In recent decades varies extremophiles were found deep in the lithosphere. Experimental studies showed that life is possible at 121 °C (Takai et al. 2008) and the gigapascal range (Sharma et al. 2002), which is beyond the p-T-range of the investigated lithosphere. Knowledge on the kinetic stability of vital molecular compounds, like ATP, can help us constraining the conditions possible for life.

All metabolism relies on the exergonic enzymatic hydrolysis of adenosine triphosphate (ATP) to adenosine diphosphate (ADP). At elevated temperatures, the enhanced kinetics of the non-enzymatic hydrolysis counteracts the enzymatic driven reaction; hence, it will limit the bioavailability of ATP.

We used an autoclave and a hydrothermal diamond anvil cell attached to a Raman spectrometer for in-situ investigation of the p-T-X-effects on the kinetics of the non-enzymatic ATP hydrolysis. At vapor pressure the half-lives were about 2-5 mins at 120 °C (Moeller et al. 2022). Up to 140 MPa, all results show an Arrhenian relationship in the T-range of 80-120 °C. The pressure effect can be best described by a power law; below 500 MPa the p-effect is vanishingly small, and above the rate constant increases exponentially. Addition of MgCl₂ up too 4 wt% slows down the hydrolysis. A distinguished effect of NaCl and CaCl₂ was not observed.

The proposed limit for ATP-based life of 195 °C by Moeller et al. (2022) is lowered by additional pressure or elevated by MgCl₂, respectively. These observations strengthen the idea that life could exist far deeper in the lithosphere as discovered yet.

Two granitic plutons are exposed at Dubair and Shang in the vicinity of Besham, northern Pakistan, in the northwestern part of the Indian plate. Both granitoids mainly consist of perthitic feldspar, plagioclase, and quartz together with minor biotite, amphibole, and accessory ilmenite, apatite, titanite, and zircon. They are peraluminous and alkali-calcic to alkaline in composition, with strong A-type affinity (Ahmad et al., 2021). La-ICP-MS U-Pb dating and trace element analysis of zircon from both plutons were performed to elucidate their emplacement ages and temperatures. Most of the zircons are characterized by oscillatory zoning, depletion in light REE, and enrichment of heavy REE, with pronounced positive Ce and negative Eu anomalies. U–Pb zircon dating of the Shang and Dubair granitoid reveals similar concordant Palaeoproterozoic ages of 1871± 8.1 Ma and 1862 ± 7.5 Ma, respectively. The calculated Ti-in-zircon temperatures mainly range between 800°C and 900°C. The U-Pb ages, zircon compositions, and high magmatic temperatures suggest solidification of the granitoids from a crustal-derived magma emplaced during the Paleoproterozoic.

Reference

Ahmad, T., Arif, M., Qasim, M., & Sajid, M. (2021). Petrology of granitoids from Indus syntaxis, northern Pakistan: Implications for Paleo-Proterozoic A-type magmatism in north-western Indian Plate. Geochemistry, 81(1), 125693.

The seismic signature of landslides preserves information of utmost importance in reconstructing the impact forces induced by landslides and, subsequently, the trajectory of motion and the dynamic properties of the sliding mass. Several studies focusing on large-scale events successfully inverted the source-time function and, therefore, the time-varying force exerted on the surface from the observed low-frequency (<0.1 Hz) seismic waves recorded in the far field. Nonetheless, most landslide events are small in terms of the displaced mass, which is more likely to excite rapidly attenuating seismic waves. With dominant frequencies above 1 Hz, these waves are noticeable only at the stations near the landslide. Analyzing the seismic signal generated by landslides in the near field is challenging. The proposed models would require a thorough description of the ground propagation medium, which is only available for some study cases. Here, we investigate using analytical solutions to Lamb’s problem to simulate the propagation history of the surface waves during the April 2022 Guanyuan landslide, Taiwan. This landslide mobilised more than 100,000 m³ of rock and stopped the traffic on the Taiwanese Central Cross-Island Highway for 43 days. The proximity of the landslide to a broadband station located about 6 km away allows the study of the near-field seismic signals. The duration and amplitude of the force retrieved in this fashion agree with qualitative observations, suggesting the potential of the model to extract source characteristics of landslides from seismic signals recorded in the near field.

Tsunamis generated by submarine or coastal landslides are a growing area of scientific interest. Events like the 2018 tsunami in Palu, Indonesia, have highlighted their destructive potential. Landslides can generate extremely high tsunami waves, but typically have a limited propagation range beyond 100 km. Areas close to the landslide are most affected. Unfortunately, early warning systems are not effective for this type of tsunami due to the short warning time interval between wave initiation and coastal impact.

This study aims to analyze the coastal and submarine landslide susceptibility for coastal areas. Limited data availability, including high-resolution bathymetric data and historical landslide tsunami catalogs, poses a major challenge. A heuristic model is used, incorporating historical case studies to calibrate and weight the parameters. Geologic, morphologic, and geometric parameters of coastal areas are considered.

First results show a high correlation of landslides generated during the Palu earthquake with the size of catchment areas of rivers entering the ocean. This parameter is strongly related with the sediment load that is transported into the ocean. High sedimentation rates might lead to the formation of thick, unconsolidated sediment layers., which are susceptible to landslides. This correlation will be further analyzed.

The results of this susceptibility mapping can help raise the awareness of the risks associated with landslide tsunamis. Even minor earthquakes, not expected to trigger tsunamis, could induce submarine or nearshore landslides and generate a tsunami in vulnerable areas. Consequently, adapting tsunami evacuation strategies to account for landslide-induced tsunamis may be required in these areas.

Plutonic xenoliths in volcaniclastic rocks from the Laacher See (LS), East Eifel and the Rockeskyller Kopf Volcanic Complex (RKVC), West Eifel, were studied. They show different ways of magmatic carbonate formation at plutonic levels.

Well-preserved original igneous textures of carbonate-bearing syenites were observed in LS plutonic xenoliths. Calcite is often crystallised in “micropegmatitic texture” with sanidine and nosean. These structures argue for syngenetic crystallisation of calcite and main silicate minerals in alkali syenite melts in the case of the LS volcano. Different proportions of euhedral calcite and silicate minerals point to calcite cumulate formation.

Occurrence of calcite associated to apatite, magnetite, phlogopite and pyrochlore in nosean syenite from xenoliths of the RKVC is in line with the assumption of magmatic carbonate formation in a highly fractionated undersaturated silicate magma.

Next to carbonatite - nosean syenite xenoliths and sanidinite, a series of different mafic xenoliths were found around the RKVC, from amphibolite to pyroxenite and magnetite cumulates, that could indicate one or more magma chambers below the volcano.

A comprehensive data set for geochemistry, mineralogy and mineral chemistry of the carbonates of LS and RKVC volcanoes is provided. Characteristic carbonate and whole rock trace element patterns are presented. Different chondrite normalised REE signatures of RKVC and LS argue for different ways of fractionation in these volcanic systems.

Complex field relationships and association to alkaline ultramafic rocks, textural diversity and locally marked isotopic heterogeneity of ijolites lead to contrasting petrogenetic concepts for these rocks. They may either be formed by magmatic differentiation from nephelinitic magmas or by assimilation of silicate wall rocks in a carbonatite melt formed after metasomatic reaction during its’ ascent from mantle to crustal levels. We show new petrographic and mineral chemical results from the ijolite type locality, Iivaara. It is the aim of this presentation to set constraints to ijolite formation in the Iivaara alkaline complex and to discuss applicability of contrasting petrogenetic concepts. Pegmatitic growth, comb layering or brecciation indicate ijolite crystallization from a low viscosity and volatile rich melt. Small scale textural heterogeneity reveals locally highly variable crystallization conditions characterized by steep temperature gradients and sudden pressure drop. Irregular clinopyroxene zonation points to repeated disturbance of magmatic crystallization at depth prior to emplacement at the actual erosion level. Veins and matrices of breccia are dominated by clinopyroxene next to titanite and apatite attesting to the high Ca-concentration of a fluid that is violently expelled from the magma. The transitional zone between wall rocks and ijolite, too, is dominated by pyroxenitic compositions. Lack of a clearly defined contact between ijolite and wall rock is in line with the observation of migmatitic textures in high grade fenites, which probably obtained plastic behavior with increasing degree of fenitization. Such fenites with syenitic composition or partial melts of them may have been assimilated by ijolite.

The study aims to provide valuable insights into the dynamics of the interaction between carbonate melts and silicate wall-rocks during ascent and emplacement of carbonatitic intrusions. A specific focus is given to potential processes leading to rare earth element (REE) enrichment. It can be assumed that the interaction of silicate rocks with carbonate melt is diverse. Therefore, a study of granites interacting with a carbonatite melt was used to carefully assess the effects of a specific lithology.

The research centers the Bulhoek carbonatite complex, a bi-partite intrusion (Bulhoek North and South) situated in the eastern central region of the Bushveld Complex, approximately 35km west of Pilanesberg (South Africa), where it intruded the Nebo-granite (an integral part of the Bushveld Complex). The key characteristics of this intrusion are reflected by volcanic breccia, finitized Nebo-granite and beforsite (fine-grained magnesio-carbonatite) containing abundant apatite and strongly disaggregated granite xenoliths. Textural evaluation indicates that the element budget of the granites was resorbed by the carbonate melt. An integrated analytical approach, involving scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), and whole-rock analysis, is currently in progress to reveal the intricacies of the carbonate melt – granite interaction. While previous field studies have touched upon the fenitization of the Nebo-granite, a comprehensive understanding of the entire (and mutual) interaction remains a significant research gap. This study bridges this gap and will deepen our knowledge of carbonatite formation.

Carbonatites are igneous rocks with significant concentrations of rare earth elements (REEs) and other important metals. Despite their economic potential, their origin and evolution are poorly understood. Crustal contamination can significantly modify REE abundance in carbonatites. The current study provides new petrographic, geochemical, and stable isotopic insight into the processes that led to the formation of high field strength element (HFSE) bearing carbonatites i.e. pyrochlore-calcite carbonatite, and rare earth element (REE) bearing carbonatite i.e. quartz-ankerite-calcite carbonatite in the Nooitgedacht Volcano.

The Nooitgedacht Volcano is an oval-shaped body with approximately a 3 km diameter situated in the Kaapvaal Craton in South Africa. It comprises mostly calcite carbonatite with enclosures of dolomite carbonatite. Petrographically, calcite carbonatite is divided into pyrochlore-calcite carbonatite and quartz-ankerite-calcite carbonatite. The mineral assemblage of pyrochlore, apatite, magnetite, and forsterite indicate an ortho-magmatic origin while the mineral association of monazite, ankerite, and quartz represents a post-magmatic/ hydrothermal origin for the quartz-ankerite calcite carbonatite. Stable isotope data (δ¹³C = -5 to -4) and (δ¹⁸O = +7 to +16) indicate a primary mantle source for the carbonatite with subsequent crustal contamination.

In summary, petrographic, mineralogical, geochemical, and isotopic data provide significant insight into the evolution of the Nooitgedacht Volcano, highlighting a complex history of magmatic differentiation, mineral fractionation, and crustal contamination.

Carbonatites are mantle-derived igneous rocks which may comprise economically important mineralizations of REE and HFSE. Their emplacement into the crust is usually accompanied by fenitization, alkali metasomatism of country rocks caused by fluids expelled during cooling and crystallization. Often, carbonatites are associated with diverse silicate rocks like syenites, nepheline syenites or phonolites. Understanding magmatic differentiation and late-stage processes after emplacement, such as hydrothermal alteration and element remobilization and re-precipitation, is of great importance to understand the formation of HFSE and especially REE deposits.

Carbonatites and associated silicate rocks (syenites, phonolites, fenites) of the Kalkfeld group in Northern Namibia show a large range in whole-rock REE contents, heterogeneity and textural variety and are therefore perfectly suited to study the phenomena named above. Detailed petrographic and microtextural analysis of the samples was done and focused on understanding the paragenetic sequence and evolution of the samples. Within the carbonatites, the typical sequence sövite -> beforsite -> ferrocarbonatite is observed, as well as late-stage, hydrothermal mineralization of REE- bearing phases like ancylite and bastnäsite. Currently, the study focuses on mineral chemistry by means of EMPA to further differentiate processes involved in the formation and evolution of the observed assemblages. Furthermore, silicate minerals like pyroxene, biotite and feldspar observed in carbonatites of the Kalkfeld group may indicate wall-rock interaction and crustal contamination of the carbonatitic magma during ascent and emplacement. The importance of silica contamination on REE enrichment in the carbonatites of Kalkfeld group will be discussed.

Rare Earth elements (REE) belong to the most strategic materials of the 21st century with steadily growing economic importance. PRISMA, the hyperspectral satellite data, is used for the very first time to test its capability of detecting REE contents from space using distinct subtle diagnostic spectral absorption features of REE. The PRISMA hyperspectral sensor acquired 234 spectral bands over VNIR/SWIR optical regions (400–2500 nm) of the electromagnetic spectrum at a spatial resolution of 30 m and a spectral resolution ranging from 11 to 15 nm. The carbonatite occurences within the Ondoto area in North Namibia were selected as the test site. To detect the REE-related diagnostic spectral absorption parameters (absorption wavelength position and depth) the in-house toolbox (QUANTools) developed at the Czech Geological Survey was tested and four absorption features placed within 700–900 nm range were found to correlate with the carbonatites containing high loads of REE. As a result, three perspective carbonatite areas were identified as the most promising, with one site validated using the laboratory geochemical data from collected samples. The results showed a good correlation between the high REE loads mapped using PRISMA data and the ground truth data highlighting the future potential of state-of-the-art satellite hyperspectral data to explore REE deposits using contactless Earth Observation data and methods.

Funded by the Czech Science Foundation project 19-29124X.

Carbon dioxide removal and storage is required for limiting global warming to the 2 °C goal of the Paris Agreement. One method is the storage of CO₂ in deeply buried geological formations.

As part of the GEOSTOR project, we created static 3D models for two potential storage sites in the Middle Buntsandstein within the German North Sea Exclusive Economic Zone.

One 3D geological model (~1300 km²) located on the "West Schleswig Block" is based on 2D seismic data from various surveys and geophysical logs from four exploration wells. It encompasses a salt controlled anticline with 40-50 m thick Lower Volpriehausen Sandstones forming the primary reservoir target. The top seal consists of Upper Buntsandstein and unconformable Lower Cretaceous mudstones.

The other 3D geological model (~560 km²) is located within the “Entenschnabel” area and, in contrast, is based on several high-resolution 3D seismic data and geophysical logs from four exploration wells. The reservoir, which also consists of up to 65 m thick Lower Volpriehausen Sandstones, is located within the Mads Graben with erosional discordances at the top. The upper seal consists of Upper Jurassic clays and partly unconformable Lower Cretaceous mudstones.

For both models we conducted petrophysical analyses of all considered well data and calculated reservoir properties to determine the static reservoir capacity for these storage sites.

Finally, we parametrized both models in order to provide two complete reservoir models that are capable of further dynamic capacity simulations, geo-risk and infrastructural analyses aiming at an entire feasibility study within the project framework.

Geological storage of CO₂ contributes to mitigating climate change, but successful storage depends on many subsurface hydrodynamic and geomechanical factors. This study outlines the development of a CO₂ injection strategy for a potential multi-trap storage site in the German North Sea by jointly honouring the geomechanics as well as hydrodynamic and geological constraints. The site comprises three structural closures, each covering an area of tens of km². Based on site-specific geology and petrophysical data, static storage capacities of the individual closures as well as the closure combinations are estimated. Each closure has a distinct configuration and drainage area, resulting in different CO₂ phase dynamics in the subsurface, due to a different interplay of gravity, capillary and viscous forces. A 3D reservoir model is developed and used to simulate CO₂ injection with a rate of 10 Mt/a over 30 years, followed by a 100-year post-injection phase, while accounting for the regional hydraulic boundaries. The allowable pressure limit is derived using dedicated geomechanical simulations. The individual settings of each closure result in varying depths and injectivities, which lead to different numbers of injection wells and their placement due to well interaction. Furthermore, pressure accumulation occurs depending on the relative position of the closure to the hydraulic boundaries, reducing achievable capacity. Consequently, injection well planning and optimisation efforts should prioritise settings that demonstrate high injectivity, high achievable storage capacity and a high allowable pressure window.

CO₂ storage potential in sandstone formations in the German North Sea is investigated by GEOSTOR consortium. This contribution discusses some of the results from the investigation of the geotechnical impact of the storage process. We examine the injection pressure window with respect to the hydro-fractural risk of the reservoir layer or caprock in the vicinity of the injection well by performing coupled hydro-mechanical fracture analyses. Different modelling scales, formulations, failure parameters, and in-situ present day stresses are considered. The results show that 2D- or thin 3D-models may underestimate the material integrity and lead to early fracture initiation. Meanwhile, a medium-scale model of the geoformation may be advantageous in reducing computational burden while maintaining high accuracy. The results also show a good correlation with field-derived fracture gradients and formation strength tests data from the Dutch-German border.

To assess the geotechnical risk of induced seismicity on the offshore infrastructure, we enhanced our boundary element-finite element method dynamic simulator with the formulation to compute arbitrary layered half-space and double-couple dynamic sources. Verification of the numerical method shows an excellent agreement with the analytical solution. The hybrid method is able to take into account the spatially complex geometry of the geological structure. The results show that the impact of the storage process on the formations’ mechanical integrity or offshore infrastructure remains relatively low or manageable for the considered period.

In this study, we introduce an open-source benchmark gallery for a systematic verification of numerical simulations of coupled multi-field processes in geological storage and sequestration. Here, the focus lies on assessing the integrity of a host rock and/or geological barrier, which requires understanding material failure and behavior under different thermal-hydraulic-mechanical-chemical (THMC) conditions. To support quality assurance of the simulation workflows, the gallery provides automated benchmarking and peer-reviewed code development.

Since closed-form solutions covering all aspects of non-isothermal two-phase flow in deformable media (TH²M) problems are not available, the verification procedure is subdivided into simpler conceptual models, up to single-variable processes (Grunwald et al., 2022). These reduced complexity problems can be described by semi- or fully analytical solutions. Extensive verification of very basic combinations (T/H/M/HM/TH etc.) was already conducted, therefore, focus lies on the investigation of more complex problems.

In the context of TH²M systems, the gallery includes three cases relevant to CCS:

• THM problem: Thermally induced expansion of liquid and solid phases resulting in thermal strain in the surrounding solid matrix and fluid displacement. (Booker and Savvidou, 1985; Chaudhry et al., 2019)

• TH² problem: Phase change and heat transport in a thermal gradient (Udell and Fitch, 1985; Helmig et al. 1997)

• TH²M: Heat loss to under- and overburden due to non-isothermal, supercritical CO₂ injection into reservoir. (LaForce et al. 2014a and 2014b; Green at al. 2021)

The gallery consists of comprehensive browser-integrated problem descriptions, analytical solutions, and numerical simulations obtained with the open-source simulation tool OpenGeoSys (Bilke et al., 2022).

The reliable estimation of the dynamic storage capacity for CO2 storage is a significant challenge due to the uncertainty of process parameters. In our study, we consider storage in the Triassic Bunter sandstone underneath the German sector of the North Sea.

We investigate CO2 injection into a saline aquifer, such as the Volpriehausen Sandstone by means of numerical simulations, to analyze the impact of parameter uncertainty on storage efficiency.

One of the main challenges for capacity estimations is the paucity of measurements regarding storage rock units like the Volpriehausen Sandstone for important process parameters such as relative permeabilities obtained from wells in the German North Sea. This requires the supplementation of measured parameters from the same storage rock units for instance from neighboring countries such as the Netherlands or Denmark.

We conduct flow simulations using TOUGH3 ECO2N and a self-developed framework for sensitivity analysis to investigate the parameter uncertainty of process parameters on storage efficiency.

Our results indicate that the level of uncertainty can significantly affect the estimation of storage capacity, and the accuracy of simulation results is highly dependent on certain input parameters.

This study provides insights into the impact of parameter uncertainty on the efficiency of CO2 storage. These findings are useful for future exploration, characterization, and operation of CO2 storage sites.

For successful and safe underground CO₂ storage, a profound knowledge of the subsurface and its geological structures characterizing the selected reservoir is essential. Besides robust geological models and storage capacity estimations, seal integrity analysis and the identification of potential seal-bypass systems is crucial to ensure save long-term storage of CO₂ in the deep subsurface. Within the framework of the GEOSTOR project, we assess potential Triassic and Jurassic CO₂ reservoirs by analysing the integrity of overlying barrier formations below the German North Sea. For this purpose, we use recently acquired high-resolution 3D seismic data covering an area of 94 km² within the northwestern German North Sea (“Entenschnabel”) and high-resolution 2D seismic data from the central German North Sea (“West Schleswig Block”) covering a total length of about 1500 km. Seismic amplitude anomalies indicate the presence of fluids allowing the investigation of former fluid migration pathways and their connection to faults and salt structures. First results from the “Entenschnabel” show a highly resolved 3D image from the seafloor to the Zechstein covering the salt diapir Belinda. Bright spots indicate fluid migration along the crestal fault system. Direct fluid migration indicators are scarce within the West Schleswig Block. Locally, bright spots indicate fluid migration along crestal faults of salt structures. We compare and discuss the characteristics of identified fluid migration pathways near the salt diapir Belinda with fluid migration and its correlation with faults and salt structures from the central German North Sea in the context of barrier integrity for subsurface CO₂ storage.

Tunnel valleys are among the deepest erosional structures in formerly glaciated areas. Our project aims to provide a synoptic model of the distribution, dimensions and evolution of Pleistocene tunnel valleys and their infills in northern Germany. The results will be used to assess the potential for future tunnel valley formation, which may pose a threat to the long-term (i.e., the next 1 Ma) safety of a radioactive waste repository.

In the first phase of our project, we produced a new overview map of the Pleistocene tunnel-valley network. From this map, we extracted the tunnel-valley thalwegs and classified them into zones of similar maximum depths. Zones of deep erosion (>400m) follow the large-scale geometry of the North German Basin. The map of maximum depth zones can be used as a planning tool for long-term safety assessments.

The next phase of our project includes a regional analysis of the tunnel valley network and local case studies. The regional analysis will compare the trends observed in the tunnel-valley network with regional geological features such as faults, salt structures and basin-fill architecture. The correlation between tunnel-valley trends and faults is ambiguous. Parallel trends occur mainly where ice advance directions were parallel to fault trends.

As a first case study, we use high-resolution 3D seismic data from the German North Sea that image two intersecting tunnel valleys. Initial results show at least three distinct seismic units correlating with different sediment types and patterns, and possible multiple use of the tunnel valley.

Paleoseismic investigations in Hamburg and Peissen document paleo-earthquake structures, e.g. large clastic dykes, infill structures, complicated folds, fault-systems and vertical injections as larger structures. Smaller structures include special forms of diapirs, seismically induced soft-sediment deformation structures (SSDS), special flame structures, shear bands, among others. Plastic deformation is dominant in Hamburg, brittle deformation dominates in Peissen. The seismic deformations can be attributed to different mechanisms, e.g. compression as a result of seismic shock or sediment intrusion, liquefaction, fluidization, strain, shear stress, volume loss and subsequent collapse as a result of blowout activity. The observed structures show certain properties that allow a distinction from non-seismic forms (e.g. glacitectonic and periglacial deformation). Dyke structures are partly of Holocene age.

We discuss the structures associated with the Eichsfeld-Altmark-Swell (EAS) in Central Germany, using observations from published cross-sections, outcrops, few boreholes and reflection seismics in a some 200 kilometres long swath in Central Germany. The EAS is well-documented as an approximately NNE-SSW-trending Permo-Triassic intrabasinal high, expressed by reduced thickness, facies changes and unconformities. It was accompanied by depocenters trending parallel to its axis, which changed in position and magnitude during geologic epochs. North of the Harz Mountains an approximately 10 km wide strip of the EAS´s western flank is strongly structured by faults of the Braunschweig-Gifhorn-Fault Zone (BGFZ). There, local thickness reductions of several hundred meters, in places culminating in complete absence of Lower and Middle Buntsandstein and apparently often associated with salt tectonics, are documented by seismics and well data, contrasting with the regional thickness reductions in the range of tens of meters typically attributed to the EAS. In Keuper time areas with large Buntsandstein hiatuses turned into depocenters. The spatial relationships of these depocenters with bordering normal faults and associated salt structures indicate that the western flank of the EAS was influenced by strong extension (up to 5 km) along low-angle normal faults detaching in Zechstein evaporites. No prominent basement offsets are observed, although they become prominent along trend of the BGFZ in the aligned westward terminations of the Flechtingen High, Harz and Thuringian Forest basement blocks. We discuss solutions for the mismatch of strong thin-skinned extension and apparently little deformed basement.

The Einstein-Telescope (ET), a next-generation gravitational wave-detector, is a triangular shape underground facility with 10 kilometres long arms to be constructed at a depth of 200-300 meters below surface. A potential location is the Meuse-Rhine Euroregion. The success of such mega-project requires a comprehensive understanding of regional geology in terms of lithology, lithological variations and dominant structures. A solid regional geology study, combining literature review, reconnaissance study, surface and subsurface mapping, sample collection, geophysical data collection, and remote sensing methods to identify the rock units and structures present, is part of assessing the feasibility of the area. The lithology consists of soft Upper Cretaceous sediments resting unconformable on Silesian, Dinantian and Famennian units. The Dinantian carbonates and the Famennian sandstones are the preferred target units for the cavern construction. A major goal is to understand the spatial distribution of the different rock units that may be encountered during construction of caverns and tunnel. Structurally, the region shows a complex pattern of NE- SW striking Variscan folds and thrusts and (N)NW –(S)SE striking faults linked to the Lower Rhine Embayment. Changes in the lithology due to folds and thrust are important in terms of tunnel planning. The (N)NW – (S)SE structures provide pathways for fluids and are potentially seismic active and hence may affect the construction and the operation of the ET severely. Understanding the regional geology allows for optimization of the location and orientation of the ET infrastructure and identifies the potential impacts during construction and operation of the ET.

Both the sustainable use of our resources and the prevention of geohazards requires reliable information about the spatial distribution of soil and geological properties. Since direct measurements are costly, artificial intelligence (AI) methods are used to estimate these attributes, leveraging a machine learning algorithm which relates laboratory measurements or expert class information to environmental covariates derived, e.g. from relief, geology and climate data. This study evaluates random forest (RF) as an AI technique to predict the occurrence of debris on slopes of the entire Black Forest in 10 m resolution. It also examines whether RF models can be applied to measured geogenic radon potential (GRP) for assessing the risk of possibly harmful radon concentrations inside buildings in Baden-Wuerttemberg.

A suite of 6770 expert class labels indicating whether hillside debris of at least 1 m thickness occurs or not, were associated with main geological classes and various terrain attributes obtained from a LiDAR-based digital elevation model. RF classification showed very good results with an accuracy rate of 86 %. GRP mapping is currently based on 580 radon measurements in soil gas at 1 m depth and a set of covariates comprising soil attributes, climate variables and geological data such as uranium concentrations. Preliminary results indicate that the GRP map generated by using a state-specific RF model is highly useful in identifying municipalities as vulnerable areas for which action is needed to mitigate this particular threat to human health.

The increasing digital provision of geological maps leads to a growing need for data harmonisation in order to make the data usable across borders. An essential prerequisite for this is the harmonisation of the geological general legends. Therefore, the main objective of the ConSent project was to establish interoperability between the existing large-scale geological map series (GK25/50) for the example of the federal states of Baden-Württemberg and Bavaria. Furthermore, the project is about the automated derivation of small-scale from large-scale geological maps. First, the geological general legends of the GK25/50 of Baden-Württemberg and Bavaria were implemented as hierarchical vocabularies in the thesaurus management system of BGR (RDF-enabled using standardised vocabularies based on semantic web concepts). The next step was to identify the greatest common denominator of the geological legends of the two federal states. This was done by an overarching geological general legend (OGL). Subsequently, the geological general legends of the two map series were linked semantically to the OGL using the SKOS vocabulary. Then, a merged GIS dataset of the GK25/50 was created containing the original geometries of both federal states. The polygons are attributed with both the original terms and the harmonised terms of the OGL. The harmonised map is publicly accessible via the project web application at BGR. Finally, the map was successfully generalised into three superordinate map scales (GK250, GK500, GK1000). The project shall be extended to other geological surveys.

The high-energy processes during the Elsterian glacial stage have formed a diverse relief of the base Quaternary with buried tunnel valleys, which are cut between a few tens of meters up to 400 m into the Tertiary bedrock sediments (Kuster & Meyer 1979). The Quaternary deposits host large groundwater reservoirs and are an important source for mining sand and gravel. The buried tunnel valleys also help to predict the erosion depth of future glaciations in the context of finding a site for a repository for radioactive waste in Germany. Therefore, it is crucial to provide a comprehensive geological model of the base Quaternary in order to support planning strategies in sustainable resource extraction and land use.

Kuster & Meyer (1995) published a contour map of the base Quaternary in Lower Saxony. Since then a vast number of new datasets were obtained. We started modelling a 3D surface based on these new datasets and the original contour map by Kuster & Meyer (1995) using SKUA-GOCAD™ (AspenTech). Here, we are presenting the first completed sub-region of this model, pointing out both the major advances that we achieved by integrating new borehole and seismic data (2D/3D) as well as the challenges of data harmonization. We were able to identify tunnel valleys that were unknown before and to revise the geometry and depth of known subglacial channels. The depth of the base Quaternary was adjusted by up to 150 m in certain areas.

Mapping the Quaternary base is required for various processes. Accordingly, it serves as a necessary horizon for set-up of 3D geological models of the subsurface, as well as a database for engineering geological processes. The most important field of application in Brandenburg considers hydrogeological questions such as the separation of the freshwater/ saline-water level in aquifers. Reliable and detailed working basis are needed for sophisticated modelling and to ensure the integration of all different data and information leading to area-wide maps.

At the geological survey of Brandenburg data of more than 200 000 drillings (from the beginning of 1900 until today), seismic profiles (average profile density of 0.7 km/km²) and gravimetric measurements (average point distance of c. 5 km) are available. In recent years maps of the Quaternary base were constructed independently by specific tasks and requirements. As a consequence, ten different maps were produced in the period from 1970 to 2014. Scaling varies between 1:10 000 to 1:1 000.000, while those with the higher resolution cover only parts of Brandenburg. The aim of this study is to combine all datatypes to create a holistic model, which can be used interdisciplinary. The varying quality and quantity, as well as the large age range of the incoming data pose a challenge being solved with different modelling approaches and geostatistical methods.

The Geological Data Act (GeolDG) came into force on June 30, 2020. It has replaced the Mineral Law (LagerstG) and has lead to a comprehensive new legal regulation in the field of recording, archiving and publishing geological data. The primary objectives of the Act are to safeguard geological data and make it available to the public, to ensure the sustainable use of the geological subsurface, and to be able to identify and assess geohazards.

Therewith it also affects clients of geological investigations and those commissioned to carry them out, e.g. drilling companies, etc. There is an obligation to notify the competent authority of all geological investigations at least two weeks before they begin. Data transmission and public provision is also regulated by means of deadlines. The term "geological investigation" includes all general geological, raw material geological, engineering geological, geophysical, mineralogical, geochemical, pedological, geothermal, hydrogeological and geotechnical measurements and recordings of earth's surface, geological subsurface, of ground or groundwater, obtained by means of prospecting, drilling, field or borehole measurements and other exploration methods such as remote sensing, as well as the processing of the data obtained in this way, as well as analyses and evaluations of these data, e.g. in the form of expert reports, surveys, and reports.

With the contribution here the law is presented fundamentally and for the execution of the law announcement procedures in the countries as well as processes of data transmission and administrative procedures for data supply.

Natural hydrogen (H₂) exploration is particularly focused on surface emissions (seeps) and soil-gas prospections, similar to early petroleum reservoir explorations. However, defining the amount of H₂ at the surface that indicates a potentially economic resource is impossible, and identifying its origin is challenging due to the fact that geological H₂ concentrations and isotopic composition can overlap with the in-situ biological signature. The potential for H₂ generation in surface environments as a result of microorganisms, corrosion of iron particles or minerals, or even drilling (artificial H₂) must be extensively evaluated. Despite these limitations, similarities to hydrocarbon systems suggest that certain seeps, which typically occur in correspondence with faults, are an expression of advection (not diffusion), driven by pressure gradients, and thus can disclose the existence of pressurized pools (Etiope, 2023). The fluid dynamics of gas seeps can therefore reveal the nature of the H₂ supply system. Comparing seep flux rates with potential H₂ generation rates, either via radiolysis or serpentinization, is a fundamental exercise for determining whether the H₂ system must include a reservoir, similar to conventional natural gas systems, or if the H₂ observed at the surface originates from continuous flow crossing short-term accumulations or directly from the source rock, as some scholars have hypothesized. However, analyses of the gases associated with H₂ (such as CO₂, CH₄, N₂ and He) are always advised. Assessing the potential of a geological H₂ resource necessitates a holistic approach that integrates multiple geochemical, ecosystem, and geological data.

References

Etiope G., (2023) https://doi.org/10.1016/j.ijhydene.2022.12.025

Even if measurements of high H₂ concentrations in continental rocks have significantly increased in the last decade, the origin of H₂ remains enigmatic in this context. Here we show that the localities in continental rocks where H₂-rich gases have been reported are mainly located near orogenic gold deposits. Two types of geomorphological features were identified near orogenic gold deposits on satellite images. They consist in both barren ground depressions and high densities of self-organized, small (< 20 m in diameter) circular- and comet-shaped white spots in 32 and 7 localities, respectively. Fe-carbonates commonly occur near gold deposits since gold is transported in CO₂-rich fluids. Thermodynamic modelling reveal here that they can further dissolve in the presence of aqueous fluid to produce magnetite and up to ~ 1 mole of H₂ per kg of rock. This reaction leads to a volume decrease of ~ 50 %. Based on these findings, we propose that Fe-carbonate dissolution could be the primary source of H₂ in orogenic gold deposit areas, and involved in the formation of the geomorphological structures reported here. The association between H₂-rich gas and ground depressions was also observed near other formations containing Fe-carbonates such as iron formations and carbonatites. This suggests that H₂ production through Fe-carbonate dissolution is not restricted to gold deposits. The global H₂ production in crustal rocks associated with Fe-carbonate alteration is estimated to 3 x 10⁵ mol/yr.

H₂-bearing fluids (pH 10 – 12) issued in alkaline springs found in several ophiolitic complexes worldwide are believed to result from the alteration of ultramafic rocks by infiltration of meteoric waters. The mineralogical fingerprint of the reactive percolation of such an alkaline fluid is revealed by veinlet mineralization occurring in the New Caledonian ophiolite (Massif du Sud). In two localities separated by ~ 15 km (Georges Pile and GR2H mines), late veins in a partially serpentinized peridotite contain magnetite crystals younger than 2 Ma as inferred from (U-Th)/He geochronometry. While the serpentinite host at Georges Pile is largely overprinted by lateritic weathering, primary parageneses are preserved at GR2H. There, magnetite occurs along with dolomite and Fe-poor lizardite as filling in millimeter sized veins cross-cutting the mesh texture of the partially serpentinized dunite. Temperature of the aqueous fluid from which the vein material precipitated is estimated to be ~95°C from in situ δ¹⁸O data on the magnetite-dolomite pair, indicating a low-temperature alteration process. Thermochemical calculation shows that this aqueous fluid was alkaline and most likely H₂-bearing. Chemically, it strongly resembles waters that are issued today in H₂ and CH₄ – bearing (hyper)alkaline springs of the Massif du Sud. δ¹³C isotopic composition of dolomite is exceptionally high, between 7.1 and up to 17.3 ‰ and is interpreted as evidence for low-temperature methanogenesis.

The alteration of ferroan brucite, a common by-product of serpentinization, has been proposed as a H₂ source at low temperature. Here, synthetic ferroan brucite with Fe/(Fe+Mg) = 0.2 was reacted with pure water at temperatures ranging from 348 to 573 K in 29 experiments either conducted in gold capsules or in Ti-based reactors. H₂ production monitoring with time and characterization of the reaction products revealed the occurrence of the following reaction: 3 Fe(OH)₂^brucite = Fe₃O₄ + H₂ + 2 H₂O. This reaction proceeded completely in ~ 2 months at 378 K and was thermally activated. The small grain size of the synthetic brucite (40-100 nm) was similar to observations in natural samples, and was probably responsible for the high reaction rate measured. H₂ production reached a plateau and Fe-bearing brucite also precipitated as a reaction product, suggesting the achievement of equilibrium. The thermodynamic properties of Fe(OH)₂ were refined based on the experimental dataset and differ by less than 5 % from previous estimates. However, ferroan brucite is predicted to be stable at an hydrogen activity one order of magnitude lower than previously calculated. As a result, significant H₂ production during ferroan brucite alteration at low temperature requires efficient fluid renewal. Such a mechanism strongly differs from olivine serpentinization which can occur even at high activity in H₂ and thus with limited water renewal.

TCEs stands for technology-critical elements, a group of chemical elements for which imbalances between supply and demand exist or are considered likely to exist. The concept is economic and geopolitical and is not based on any scientific consideration. The term TCE is linked to competition for natural resources, now dramatically intensified by geopolitical instability and the green-energy transition.

Since it is a geopolitical concept, the elements that are considered as TCEs depend on the country and change over time; basically, they depend on the "eye of the beholder". For example, in the EU list of 2023, compared to the 30 Critical Raw Materials (CRMs) of 2020, there are six new CRMs (arsenic, feldspar, helium and manganese, plus copper and nickel as Strategic Raw Materials) and two have disappeared (indium and natural rubber).

Currently, the European Union considers a large number of materials to be technologically critical (mostly, but not all, chemical elements): 51. Given that the total number of elements in the periodic table is 118, of which 94 occur naturally on Earth and the remaining 24 are synthetic, this means that we are talking about ≈50% of all naturally occurring chemical elements!

In this context, what are the reasons for studying the environmental and (eco)toxicological effects of TCEs? Obviously, they will be different in the European Union than in the producer countries. In this communication, the reasons and research needs on both sides of the so-called supply chain (producers and end-users) will be analysed.

Technology-critical elements (TCEs) show a dramatic increase in industrial applications in recent years and decades. Technological applications in our everyday life have come a long way in the number of used elements, with almost every element of the periodic table today. Based on the fact that many TCEs are recycled only to a very small extent or not at all, TCEs may become contaminants of high concern in the future.

Yet, important knowledge gaps remain about the environmental behavior of TCEs and their uptake into the food chain. Therefore, tools are needed that enable a sound and reliable determination of TCEs in order to further understand their impact on the environment. We present the advantages of N₂O as a reaction gas for inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) for the multi elemental analysis of the majority of TCEs (e.g.: Ga, Ge, In and Ta). Thus, allowing the determination with LODs between 0.00023 µg L^-1 (Eu) and 0.13 µg L^-1 (Te). In addition, we used a microwave assisted closed vessel digestion to determine non-certified TCE mass fractions within four commonly used reference materials in the field of environmental marine chemistry: NIST 2976 (mussel tissue), NIST 1566a (oyster tissue), BCR 668 (mussel tissue) and NCS ZC73034 (prawn). Presenting mass fractions for Ga (11 µg kg^-1 ± 9 µg kg^-1 - 63 µg kg^-1 ± 8 µg kg^-1) and In (0.39 µg kg^-1 ± 0.29 µg kg^-1 – 0.7 µg kg^-1 ± 0.7 µg kg^-1) as non-certified elements within all of these CRMs.

TCEs have a wide-spread range of applications and are released into the aquatic environment in various ways. For their sound determination in natural waters not only new analytical methods are needed but also reference materials for method validation. Even though a wide variety of certified reference materials (CRMs) of different water matrices are available, certified values of many elements, especially TCEs, do not exist. In this study, an online preconcentration method coupled with ICP-MS/MS was used for the quantification of 34 elements among which are 21 TCEs. The method was applied to 17 water CRMs and measured data is combined with a comprehensive literature review on non-certified values in the CRMs resulting in the suggestion of consensus values for various TCEs.

The method is applied to a set field samples from German rivers and from the North Sea in order to trace different inputs of TCEs into the aquatic environment: In and Ga ware analyzed as tracers for offshore wind farms where they are applied in corrosion protection systems. The Gd anomaly was used as a proxy of coastal and riverine inputs into the North Sea in an attempt to differentiate anthropogenic from geogenic signal. The concentrations in seawater ranged between 0.011 ng L^-1 ± 0.001 ng L^-1 and 0.27 ng L^-1 ± 0.15 ng L^-1 for In and between 1.37 ng L^-1 ± 0.05 ng L^-1 and 4.9 ng L^-1 ± 0.5 ng L^-1 for Ga and Gd anomalies of up to 4 were found in the North Sea.

The picturesque fjords along Norway’s coastline play an important role for the country’s tourism and aquaculture industry. Despite their economic importance for the country, surprisingly little is known about the occurrence and behaviour of rare earths and yttrium (REY) in Norwegian fjords. We will present dissolved (0.2 µm-filtered) REY data for different sites and depths from several Norwegian fjords with focus on the Seaward Basin in the Trondheimfjord. Our sample set is complemented by data for rivers feeding into the fjord (Orkla, Gaula, Nidelva, Stjørdalselva) and for two waste water treatment plants (WWTPs) releasing their effluents into the Seaward Basin.

All fjordwaters show REY concentrations in a similar range with decreasing concentrations with increasing water depth. Their shale-normalised (_SN) REY patterns share common features with typical seawater patterns, however, light and middle REY are less fractionated compared to open-ocean water. Samples taken close to river mouths have notably higher REY concentrations in surface layers with very flat REY_SN patterns, similar to the rivers investigated and characteristic of boreal rivers with a high nanoparticle and colloid load. In contrast, the truly dissolved (< 1 kDa) REY in river water of the Nidelva show patterns similar to those of seawater.

The effluents of the WWTPs carry a strong anthropogenic Gd signal into the Trondheimfjord, which results from the application of Gd-based contrast agents in magnetic resonance imaging. However, no anomalous enrichment of Gd is detected in the Seaward Basin itself because the large water volume immediately dilutes and obliterates the anthropogenic signal.

Contrasting sediments behave radically differently in aquatic systems, releasing elements of concern. Their behavior is a function of mineralogy, geochemical composition, and the conditions of the medium (e.g., ionic composition, pH). One way of understanding the reactivity of contrasting sediments, but also the operationally defined fraction of the associated elements is to use selective extraction protocols. Nevertheless, these are generally used without verifying the adequacy of the extraction times, in accordance with the sediment characteristics, nor the potential impact of element-specific behavior to the extracting reagents, biasing the final interpretation. This study aims at providing such understanding for the rare earth elements (including lanthanides, yttrium, and scandium). The sediments used originate from modern aquatic sedimentary environments of both terrestrial and marine-transitional origin, associated to either natural (beach and riverbank sediments) or anthropogenic (mine tailings) sources. A qualitative mineralogical determination of the sediments was performed via XRD. Element mobility was studied via selective extraction protocols applied in parallel, with a kinetic approach, and sequentially. Quantitative analysis of the total concentrations of major and trace elements was determined via XRF-EDX, ICP-OES and ICP-MS, to obtain elemental correlations and total REY+Sc sediment content for mass balance purposes. For each extraction solution, the elemental concentrations were quantified via ICP-MS. The information gained in this study provides further experimental results on the unknown aquatic behavior of REY+Sc elements, for which there is currently an increasing demand for major technological applications.

Acknowledgements:

Funded as part of the Excellence Strategy of the German Federal and State Governments.

Material flow data are generally used to assess the environmental footprint of economic activities, e.g. through life cycle assessments (LCAs). This is particularly relevant for the resource-intensive sector of primary raw material extraction and the associated raw material supply chains. As LCAs are firmly established in industry, research, and governmental organizations to support decision-making, e.g. for comparing the environmental impact between recycling processes and primary raw material extraction, an up-to-date and transparent database is the basis for meaningful results. However, the ecological parameters for primary raw material extraction up to refining in the databases often do not reflect the current status. In addition, the data for many metals are often only aggregated values and not available for individual process steps of mining, processing, smelting and refining.

To address this challenge, we conducted a comprehensive survey of emissions data and other project- or deposit-specific data on copper mining, smelting and refining, and correlated the results with currently available general sector data. The data collection was carried out, on the one hand, through a customized questionnaire completed by the companies participating in the studies and, on the other hand, through literature research. The newly acquired project-specific knowledge enables improved calculation of the carbon footprint and greenhouse gas emissions of representative mining projects and smelters/refineries. Furthermore, it serves for a direct analysis of the calculation bases for life cycle assessments and the data on CO₂ emissions of other data providers and their evaluation.

Because of its specific properties, nickel is set to play a key role in the implementation of new megatrends such as the energy and mobility transition. Nickel is used in many industries, primarily in the manufacture of stainless steel and nickel alloys. In addition to these established areas of application, a considerable increase in global nickel demand for battery production is expected until 2030, particularly due to the rapid global ramp-up of electric mobility.

Within this decade the global nickel demand is forcast to double. While the battery production in recent years was based mainly on the dissolution of nickel metal (so-called class 1), things changed in 2022 with intermediates (mainly MHP and nickel matte) representing the by far dominant nickel feed for the batttery production.

Currently, Indonesia is the only country to significantly increase the mine production to provide the necessary nickel intermediates to meet the future demand. Indonesia holds the largest nickel reserves and until 2013 was the worldwide leading nickel ore supplier. With the introduction of an nickel ore export ban, the country became the leading producer of refined nickel products within less than ten years. Moreover, Indonesia is already the by far largest exporter of nickel intermediates for the global battery value chain. However, this dramatic change is based mainly on Chinese investments. It raises questions on the secure and sustainable global nickel supply.

Hyperspectral remote sensing already is important in geoscientific research in the fields of geology, soil, exploration and mining. New hyperspectral satellite systems are already in operation (e.g. EnMAP, PRISMA and DESIS) and more systems are planned e.g. the European Copernicus Next Generation Hyperspectral Satellite CHIME. Investigated are the information contents of hyperspectral data for exploration target recognition and their dependency on spatial resolutions of different sensor platforms. Airborne data offer high spatial resolution of 2.5 m with limited areal data acquisition, whereas hyperspectral spaceborne sensors guaranty nearly worldwide data availability with the same spectral characteristics but medium spatial resolution (30 m). The aspects of high spectral resolution and high versus medium spatial resolution targeted mineral mapping is demonstrated. Hyperspectral satellite data are analyzed successfully to map major mineralogy and proxy minerals such as hematite for the ore mineralization at Gamsberg. The results indicate, that hyperspectral satellite data are an important data source for exploration activities despite the moderate spatial resolution. However, for detailed mapping especially within a mineralization zone, hyperspectral high spatial resolution data from airborne or unmanned aerial vehicle (UAV) systems are important, to understand and to map the mineralogy of such a zone in their complete complexity.

Mechanical excavators have been widely used for the excavation of rocks in mining and civil engineering projects. The excavation of hard rocks by mechanical machines is difficult due to low advance rate and high tool wear. This difficulty can be overcome by exposing hard rocks to microwave energy just before cutting. This paper presents the newly developed a microwave-assisted laboratory hard rock linear cutting machine. The cutting machine which can be equipped with disc cutter or conical cutter has been integrated with a microwave treatment system. The microwave system is composed of 25 kW-magnetron with a frequency of 915 MHz, wave guide, circulator, water load, stub tuner, and directional coupler. A rock sample is first exposed to microwave energy, then cut by cutter using the test system. During cutting tests, normal and cutting forces are measured, and specific cutting energy values are calculated. A preliminary cutting tests were carried out on some rock types using the cutting machine at different microwave power levels. It was observed that the optimum specific energy values ​​of the samples exposed to microwave energy were considerably lower than those that were not exposed to microwave energy. It was also observed that the optimum specific energy values ​​decreased quite steadily with increasing microwave power. The experiments using the new microwave assisted laboratory hard rock cutting machine showed that microwave treatment of rocks before cutting was an efficient method for the excavation of hard rocks.

Modern terrestrial mantle-derived rocks display a rich diversity of isotopic compositions that have been key to understanding the assembly of the silicate Earth over the last 2-3 billion years. Parallel to these advancements was an increasing understanding that Archean-aged cratonic rocks provide a window into foundational terrestrial processes that occurred in the first 1-2 billion years of Earth history. The study and application of these distinct records remained mostly independent until statistical and instrumental precision improved enough to measure meaningful heterogeneity in short-lived radiogenic isotopes (especially ¹⁴²Nd and ¹⁸²W) among young mantle-derived rocks. Recent developments in the study of ocean island basalts have revealed that some early domains in Earth’s mantle have never been fully homogenized and may also preserve information about foundational Earth processes.

The ¹⁸²W/¹⁸⁴W records of Archean and modern rocks are especially complimentary and reflect differing perspectives on core formation and subsequent late accretion processes. On the other hand, the ¹⁴²Nd/¹⁴⁴Nd signatures of some ocean island basalts may reflect the same global differentiation event preserved by many less altered cratonic rocks of Archean age. Continuing advancement in analytical precision will increase the potential to integrate the study of Archean-aged and modern rocks as mutually beneficial tools to understand processes such as core and dynamo formation, crustal differentiation, plate tectonics, and impact events. In turn, a detailed understanding of our planet’s early history in these respects is critical to identify which terrestrial exoplanets have the geological propensity to host life.

Recently, high precision isotope measurements revealed anomalies of the short-lived ¹⁸²W and ¹⁴²Nd system in modern Ocean Island Basalts (OIBs) [1, 2]. These anomalies indicate the presence of an ancient primordial component within OIB sources, however, their origin remains enigmatic. Core-mantle interaction [2] or the involvement of early differentiated and isolated silicate reservoirs [e.g. 3] are the most plausible scenarios to account for the observed isotope anomalies. To better understand the involvement of primordial components within OIBs, comparing plume heads and tails might be key to answering this question since the amount of incorporated material changes during the lifetime of plumes [4].
Here, we present new ¹⁸²W and ¹⁴²Nd data for basalts from the Deccan Large Igneous Province (DLIP; 65Ma). By investigating Pb and ¹⁴³Nd isotopes as well as W-Th-Ta systematics, we investigated the role of crustal and lithospheric contamination during plume ascent on the short-lived isotope compositions. Our combined ¹⁴²Nd-¹⁸²W data for pristine DLIP lavas fall within the range of Réunion lavas [1, 5] that were interpreted as late-stage eruptions tapping the Deccan-Réunion plume. Consequently, while the short-lived isotope compositions can be altered due to lithosphere assimilation, pristine DLIP lavas display the same short-lived isotope compositions as their respective tail. In contrast to previous studies [4], this argues for a consistent entrainment of the same primordial components into a plume head and tail.

[1]Peters et al. (2021), G-Cubed. [2]Mundl et al. (2017), Science. [3]Tusch et al. (2022), PNAS. [4] Jones et al. (2019), EPSL. [5]Jansen et al. (2022), EPSL.

The formation of oceanic crust at mid-ocean ridges is one of the dominant processes in the chemical differentiation of our planet. Oceanic crust formed at fast-spreading ridges exhibits a relatively uniform seismic stratigraphy and is regarded as layered and relatively homogeneous. Because of the lack of in-situ exposures at the base of recent oceanic crust, existing models on the geodynamics of the deep processes during crustal accretion have never been tested directly using natural samples. The ICDP Oman Drilling Project penetrated at two sites the crust/mantle boundary in the Oman ophiolite, the best analogue for fast-spreading crust on land (drill cores CM1, CM2). We started a study investigating a continuing and densely spatial resolved sample set of both drill cores in order to shed light on the nature of this poorly understood zone at the base of the Oman paleocrust. The drill cores CM1 and CM2 cover the upper mantle harzburgites at the bottom, followed by a 90 m thick massive dunite layer with layered gabbros on top. Ni and Mg# in olivine as well as Cr#, Mg# and trace elements in chrome spinel were analyzed by EPMA and fs-LA-ICP-MS. The data reveals a homogeneous harzburgitic upper mantle composition and a dunite section showing decreasing Mg#, implying an increase in differentiation towards the top. We conclude that the zone of massive dunite was formed as a first cumulative crystallization event of a mantle-derived, primitive MORB melt, while the residual melt was fed into the stockwork system of the layered gabbros.

Refractory as well as insoluble nature of zirconium (Zr) dictates that its behavior mostly is driven by magmatic fractionation whereby Zr-rich phases, such as zircon or baddeleyite, and to a lesser amount pyroxene, can control stable Zr isotope systematics of silicate systems. In carbonatites, HFSE often are carried by pyrochlore, garnet and/or pyroxene, and scavenging of these phases during magmatic evolution of carbonatite liquids may result in significant depletions, particularly apparent for Ti, Zr and Hf. Therefore, fractional crystallization of HFSE-bearing phases may bear on the understanding of the role of carbonatites for HFSE distribution in the mantle.

We have analyzed Zr stable isotope systematics (δ^94/90Zr_IPGP-Zr) of several carbonatites from various geotectonic positions to further constrain their petrogenesis. The preliminary data shows ~0.4‰ variation which is not easily related to major element chemistry of carbonatites, nor emplacement age. Samples of unmodified carbonatites from continental rifts and hot-spots plot above the mantle value (δ^94/90Zr = 0.04 ± 0.04‰), with δ^94/90Zr of up to ~0.35‰ whereas carbonatites from shear zones display resolvedly lower δ^94/90Zr. Carbonatites overprinted by F-rich fluids carry distinctly low δ^94/90Zr, associated with high Nb/Ta, suggesting high mobility of HFSE in F-rich fluids. In contrast, δ^94/90Zr of carbonatites carrying sulfide mineralization does not deviate from that of unmodified carbonatites. These cumulative observations indicate stable Zr isotope fractionation between silicate and carbonate melts in the mantle. Besides, they also indicate strong mineralogical control of HFSE-bearing phases on the stable Zr isotope systematics of carbonatites.

Carbonatitic melts are subject to different processes during their ascent (e.g., fractional crystallization and crustal contamination), which may cause a strong change in their composition. Their original composition has not been definitively determined. In order to find indications of the primitive composition, it appears reasonable to investigate the deepest known carbonatite occurrences. One of the deepest known carbonatites is the Palabora complex in South Africa. Most of the complex is represented by varieties of pyroxenite, while the center of the complex comprises a multiple calcite carbonatite intrusion (called Loolekop). A new discovery of a second carbonatite in the southern part of the complex, reveals a head section of a stuck carbonatite intrusion, which is reflected by isolated veins on the surface and a more extensive abundance with depth. This carbonatite shows a strong enrichment in Ti (>10 wt.% TiO₂) with up to 20 modal% ilmenite. Fenitising fluids exsolved from the carbonatitic melt have even titanitised the surrounding pyroxenite. Additionally, previous investigations of the Loolekop show that the Ti content of the carbonatite increases systematically from the center of the intrusion to the margin. This could indicate a noticeably higher Ti content in the more primitive melt that crystallized in the marginal areas in comparison to a slightly more evolved melt that formed the center. Could this be an indication that primitive carbonatite melts are rich in titanium and lose the titanium rapidly during their evolution?

Carbonatites are relatively rare rocks with only about 600 occurrences world-wide. While dominated by intrusive carbonatites the rock record only shows about 50 occurrences of extrusive carbonatites. The geochemical link between intrusive and extrusive equivalents is essentially unstudied. To shed light on this topic the interface between fine-grained dolomite-carbonatite dykes and associated diatremes of the Gross Brukkaros in central Namibia was investigated. Whole rock geochemistry and petrography provide evidence that the carbonatite dykes contain significant amounts of Si and Al, which is assigned to assimilation of crustal xenoliths. At the transition from carbonatite dyke to diatreme formation, the carbonatite melt degassed (release of CO₂ and other volatiles to the atmosphere), while the Si, Ca, Mg and Fe load together with a high amount of trace elements became precipitated from a hydrothermal “magmatic-provenance-dominated” fluid during rapid temperature drop in the course of decompression as a mixture of micro- and cryptocrystalline quartz (quartz I) and aegirine-augite (plus minor magnetite). This mineral assemblage forms the matrix of the diatreme breccia. A second quartz generation (quartz II) is formed in the post-eruption environment by precipitation from a fluid resulted by a mixture of remaining fluids and an influx of meteoric waters. All measured trace elements show significantly higher contents in quartz I compared to quartz II (with exception of Li). This study provides the first holistic dataset that show how a carbonatite geochemically behave during eruption.

The Miocene Kaiserstuhl Volcanic Complex in the Upper Rhine Graben is known for simultaneously exposing both intrusive and pyroclastic calciocarbonatites. This makes Kaiserstuhl a promising candidate for studying the field and genetic relations between intrusive calciocarbonatite and its eruptive equivalent, and the processes enabling eruption of the calciocarbonatite at the surface in particular. Eruptive calciocarbonatites in Kaiserstuhl are represented by carbonatite tuff and lapilli-stone beds covering a agglomerate fan on the western flank of the volcano. The debrites represent lahar (debris flow) and possibly also debris avalanche deposits. Based on observed textures, the debris flows were most likely derived by water-dilution from debris avalanches resulting from edifice failure, which occurred in the central part of the Kaiserstuhl Volcanic Complex and ultimately exposed the intrusive system. The carbonatite pyroclasts (lapilli and ash) were ejected from narrow vents represented by open framework tuff-breccias aligned along the detachment scarp. Since the Ca-carbonates break down rapidly at high temperatures and low pressures, calciocarbonatites are unlikely to form surface lavas. On the other hand, the presence of the calciocarbonatite pyroclastic deposits suggests that some geological process faster than the high-temperature break-down of Ca-carbonate may facilitate calciocarbonatite eruption. Prompt exposure of a suprasolidus high-level carbonatite intrusion by edifice collapse may be a suitable scenario enabling calciocarbonatite eruption. The absence of edifice failures on alkaline volcanoes, where carbonatite intrusion is either supposed or exposed, may explain overall scarcity of erupted calciocarbonatites.

Intending to improve mining and exploration processes within a rock salt producing mine all available geological information were collected, evaluated and prepared to create a 3D subsurface model. Besides geological information the drifts were visualized in 3D, too. Amongst other data borehole information from above and subsurface were considered to create a block model showing the grade distribution within the deposit and the geological mining boundaries. One challenging aspect was to harmonize the borehole database that grew over several decades. The block sizes of the model were created due to the customers’ needs with respect to dimensioning issues.

Based on the results of the geological model drift planning and excavation processes can be optimized. With respect to the geological exploration program the targets can be outlined in a more distinct way using the 3D model. By precising mine design and exploration targets workflows for short and long term mine planning can be improved. Beyond that reserves and resources of the deposit can be described more precisely. By updating the model on a regular basis thickness, depth and distribution maps as well as profiles can be requested easily from the model considering all available information.

As the geological model was created with the help of SKUA-GOCAD (AspenTech®) and AutoCAD® data exchange can be realized using for example CAD-based formats as well as column-based files. Furthermore, the geological model can be implemented into a mine planning software to improve daily routine at the mine site.

The digitization of geological data is becoming increasingly important in the assessment of the subsurface geology, and 3D visualization offers new possibilities. To extend the visualization of the subsurface geology of the State of Saxony-Anhalt, a 3D structural model of Permian to Quaternary stratigraphy of the South-Eastern Harz Foreland has been created. The model is based on pre-existing data consisting of maps from large-scale subsurface exploration, seismic profiles, and c. 5,660 stratigraphic profiles from the extensive borehole database from over 100 years of drilling exploration. Data preparation consisted of extracting borehole data, digitizing and vectorizing maps and seismic profiles, and subsequent processing with ArcGIS. Modelling of the surface mesh of stratigraphic boundaries and faults was performed using SKUA-GOCAD 22 in the 'Structure and Stratigraphy' workflow. In this iterative process, inconsistencies in the topology and geometry of the mesh have to be resolved manually in several steps in order to create a consistent model. Challenges arise from low data density in some areas and conflicting information in data from different sources. The resulting model shows the arrangement and relationship of stratigraphic units and major faults of the area in a refined level of detail. Within the requirements of publication and provision of state geological data by the Geological Survey of Saxony-Anhalt (LAGB), the model was prepared to be published via the GST (Geosciences in Space and Time) framework at the LAGB.

The „Central Oder“ sub-catchment in Germany is the first of three areas for which structural models of the surficial aquitards down to the latest Elsterian till are being constructed as part of the Geo3D-Oder project. All other areas are interpreted as undifferentiated aquifers. The data base is taken from the "Lithofacies map of the Quaternary 1 : 50,000" (LKQ 50).

The model consists of ten stratigraphic layers, each bounded by a top and base horizon, and the ground surface. The data combines polygons defining the extent of the strata and point data of elevations derived from contour lines and stratigraphic logs. The data was processed and transferred to the SKUA-GOCAD modelling platform.

The geological 3D model contains only a concordant sequence of horizons with no faults. The challenge in constructing 3D models of Quaternary glacial sediments lies in the variable and sometimes very small layer thickness. Especially in the case of unavailable information on the elevation of upper horizons, layers below cannot be correctly reproduced. A new method has been developed to avoid this. For each horizon, the uppermost proven elevations of all underlying strata were identified in search quadrants. This data was used to interpolate 'virtual horizons', which are constraints on the maximum depth for each horizon. The resulting horizons were finalised using automated routines and manual post-processing.

Fieldwork represents a highlight for most students in geosciences but is associated with challenges related to diversity. Due to long periods of absence, high costs, remote destinations, and physical and mental stresses, not all students can equally benefit from the offer, for example, people with care obligations, challenges due to sociocultural status, insufficient financial resources, or illnesses. Some outcrops are generally inaccessible.

The Engineering Geology and Rock Mass Mechanics Group at Ruhr-University Bochum realizes projects towards a more diversity-friendly education in geosciences.

Within Digifit, the geological mapping course in the Bachelor’s curriculum was digitized. With 360° tours and 3D models of outcrops and rock samples, the course can be offered digitally and provides high-quality teaching material for the preparation and postprocessing of fieldwork.

DRAGON Ruhr.nrw develops digital teaching material for geosciences and civil engineering. By content relating to climate change and geohazards, such as 3D models of outcrops in the Ahr valley, students are faced with the significance of their future roles.

As part of research-based learning projects, students are currently working on a comparison between manual mapping of discontinuity orientations and the derivation of orientations from digital models.

We highlight limitations of digital fieldwork and ways to counteract them. The resulting educational material offers a diversity-open access to fieldwork. The media competence of the graduates is strengthened and the attractiveness of geosciences is increased. In addition, digital teaching content offers great potential for interdisciplinary collaborations and can be used by third parties, for example in the context of ESD.

Fieldwork and outcrops are an essential component of geoscience education, providing students with a hands-on learning experience that enhances their understanding of geological processes. This is reflected by the importance personal field experience has in the teaching of geology. While classic fieldwork remains the best way to grasp the extent and underlying processes of geological structures, 3D and VR teaching applications offer a unique opportunity to explore and visualize geological features that may be difficult to access or too large from a human’s perspective. However, state-of-the-art virtualising technology is sparsely used in geoscientific education. The commonly used toolkits to handle three-dimensional geological data are not able to process large amounts of polygons, as well as their accompanying texture-sets, derived from detailed photogrammetry datasets in real-time or VR. Here we present our current digitising workflow within the 30 Geotope³ project and how we visualise highly detailed, large- and small-scale outcrops with the use of Unreal Engine 5s Nanite and Virtual Texturing technologies. This virtual museum enables students to experience a variety of geological features in an immersive and interactive way, bridging the gap between theory and practice and enabling collaborative and remote learning. We understand the virtual museum as a starting point for interactive educational environments covering outcrops from all around the world, thus making geoscience more accessible and preserving outcrops for future research.

Volcanoes are the most dynamic landforms, capable of changing their shape and environment in a matter of minutes, posing a significant threat to the environment and populations. While modern monitoring approaches can detect short-term changes, the long-term evolution is not well understood. Through the collection and photogrammetric processing of optical data, we can now reconstruct the precise topographies of volcanic edifices during the last decades to study different stages of volcanic development. By comparing the obtained topographies, we calculate volume flows, including eruptive and eroded materials, and evaluate the resulting geomorphic changes. Recent advances in technology and algorithms have opened unique opportunities for the collection and processing of photogrammetric data, allowing quantitative analysis of aerial photographs from the mid-last century to modern satellite and drone data. Here, we present ultra-high-resolution point clouds and digital elevation models to study long-term morphological and structural changes at volcanoes. In particular, the availability of archive ground and aerial stereo imagery from the last century allows us to look into the past and reconstruct volcanic activity in glaciated regions, and explore the complex interactions and geomorphic changes these regions undergo. We illustrate volcano-cryosphere interactions in Kamchatka and Iceland, highlighting the use of the method by pioneers since the beginning of the last century. We describe the main features of the use of photogrammetry in volcanological research and discuss possible further developments in terms of improved visualization and virtual reality application for educational purposes.

Available research on glacial isostatic adjustment (GIA) in Antarctica is sparse, and there are few records of how the stress field is affected by it compared to Arctic and northern regions. Circum-Antarctic coastal and offshore tectonics reveal the presence of faults and rift systems, particularly in West Antarctica, the Weddell Sea, and Prydz Bay. These areas are characterized by a series of complex faults that displace upper sedimentary sequences to depths of 2.5 km. In this study, we investigate the potential for reactivation of glacially induced faults (GIFs) by altered lithospheric stress conditions during ice advances and retreats in past glacial periods. We compiled available information on the dip and strike directions of Antarctic rift systems from the literature and databases. Using finite element simulations that incorporate fault geometries, various rheological and current stress parameters in solid and ice sheet models, it is possible to analyse the probability of fault reactivation due to GIA for the last 200 ka. Because West Antarctica has been subject to greater changes in its ice sheet in recent recorded years compared to East Antarctica, identifying potential sources of GIFs could help us better understand how seismotectonics in Antarctica have been affected by past glacial phases and what the implications of current global climate trends might be.

The geology of the Weser river terraces to the south of Hamelin is characterized by Quaternary sediments, consisting of thin alluvium and several meters of sand and gravels, overlying the seismic bedrock. We investigated a study area along the left Weser bank south of the village of Kirchohsen using different ambient seismic vibration techniques. Borehole logs show that the thickness of the Quaternary sediments varies from around 15 m to 33.5 m.

The fundamental frequency at a measurement point can be determined with the H/V method, which is based on the ratio between the horizontal and vertical spectra of the ambient seismic vibration signals. In the study area, the resonance frequency varies from 2.6 to 6.3 Hz, where low frequencies coincide with thicker Quaternary sediments and higher frequencies with thinner sedimentary layers. Assuming a continuity of the geological units, we can directly link the H/V frequencies to the sedimentary thickness and map the transition zone between the boreholes by H/V measurements along several profiles and additional individual points. We complement these H/V measurements by a new passive seismic array measurement and the reanalysis of older measurements in order to retrieve the dispersion curves of Rayleigh and Love waves and invert them for the shear-wave velocity profile.

The combination of the different data provides a detailed overview of the lateral changes within the shallow underground structure of the sedimentary layers of the study site.

Within the framework of the project Neotectonics in the Northern Upper Rhine Graben (NeoNORG), we used a multi-method geophysical approach to obtain a detailed understanding of the fault structures within the sedimentary basin.

Using parts of a 3D seismic data set originally conducted by the petroleum industry we were able to obtain a detailed 3D structural model. It consists of two main faults originating from the basement at a depth of 2 km to about 350 m below the surface. To close the gap between the 3D Seismic data and the surface, we conducted 2D P-wave profiles with geophone spacings of 2.5 m. For the uppermost 200 m, an even higher resolved image of the subsurface was obtained using 2D S-wave seismics with geophone spacings of 1 m. Geoelectrics with varying electrode spacings and georadar using 200Mhz antennas were used to resolve the uppermost 50 m.

The combination of these different geophysical investigation methods allowed us to trace the fault zones within the sedimentary basin from the crystalline basement at a depth of 2 km into the quaternary strata, several meters below the earth's surface. We thereby reveal the (neo)-tectonic activity of the investigated area. Overall, the study provides valuable insights into the development of fault zones in the Northern Upper Rhine Graben and demonstrates the importance of using a multi-method geophysical approach to investigate the tectonic development. The obtained fault outcrop at the surface is concurrently used to investigate the relationship of radon in soil gas and fault zones.

The assessment of seismic hazard and potential earthquake secondary effects such as tsunamis in offshore environments requires, similar to onshore environments, a good knowledge of the subsurface shear-wave velocity (Vs) distribution with depth. Between 2018 and 2020, a seismological campaign with Ocean Bottom Seismometers (OBS) was performed on selected subaqueous slopes with unconsolidated sediment cover in Lake Lucerne (Switzerland) to measure ambient vibrations and to monitore earthquakes. OBS were deployed in the single station and array configurations. First, we use the single station ambient vibration data to estimate the microtremor horizontal-to-vertical (H/V) spectral ratio. Second, we follow a robust preprocessing workflow to extract the phase velocity dispersion curves (DC) from OBS ambient vibration array measurements. The estimated H/V spectral ratios and the DC are used as targets in an inversion process for the Vs profile determination. The microtremor H/V spectral ratio forward modelling routine uses a new model that is based on the seismic interferometry principles under the diffuse field assumption and considers the presence of the water layer.

Keywords: Microtremor H/V spectral ratios, Phase velocity dispersion curves, Ocean
Bottom Seismometer, Site effects, Shear-wave velocity

Reflection seismics is the most common geophysical method for obtaining structural images of the subsurface. It can image subsurface structures over large areas and depth ranges at high resolution. In order to make a reliable assessment of seismic imaging results, e.g. to quantify uncertainties, it is important to understand the concepts of seismic resolution. At brief, seismic resolution is the ability to distinguish between two seismic features from one another and resolve them separately.

Theoretical considerations to seismic resolution criteria and their implications for seismic imaging are discussed in many textbooks, but the practical use in interpretation is often difficult to achieve. This is, because the underlying parameters, e.g. the bandwidth and the velocity of the seismic signal, are not explicitly visible on the final stacked image, especially if the sections are depth converted.

However, the measure for vertical resolution is the dominant wavelength and the resolution criteria is expressed as a fraction of it, e.g. λ/4 criterion, whereas a measure of the lateral resolution is the Fresnel zone. Both of which can be computed by common functions that are available in most interpretation systems. As a result, seismic sections showing the spatial variability of both vertical and horizontal resolution are obtained that can be blended into the stacked seismic section. This gives a tool at hand – just like a seismic attribute – to estimate the limits of seismic resolution and access uncertainties in the final seismic image.

Neotectonic movements can cause severe hazards and are scientifically and socially relevant for seismic hazard assessment and utilisation of the subsurface. In northern Germany, a presumed aseismic region, little is known about these processes and the associated structures, despite proven neotectonic activity, because many faults are hidden beneath sediments. To improve the knowledge of neotectonic activity, investigations of recently-active fault zones, like the Osning Lineament (OL) in North Rhine-Westphalia, are required.

To better understand the neotectonic evolution of the OL, we used a combined approach using high-resolution 2D P- and SH-wave reflection seismics to investigate four different sites at the Bielefeld-Segment of the OL. Overall, we acquired three P-wave profiles with which we were able to image the underground down to 700 to 800m depth, and four SH-wave profiles that imaged the subsurface down to 100m depth.

The seismic profiles show good results with respect to mapping the fault inventory. In the Cretaceous, Triassic, and Quaternary several, previously unknown, northward-dipping thrust faults are evident, which have upthrusted the formations toward the south. The faults form fault splays that developed due to the propagation of the OL into the footwall. The slow shear-wave velocities, especially in the Quaternary, allow for very high-resolution imaging of the subsurface and the identified faults are evidence for neotectonic activity. More to the south, we also observed some southward-dipping normal faults, which are interpreted as basin faults of the Münsterland Basin dipping towards the basin center.

Within the feasibility study regarding the construction of the Einstein – Telescope (ET), at a depth of 200 – 350 m in the Meuse-Rhine Euroregio, various seismic methods are used for subsurface investigation and imaging. The study includes a 40 km long two-dimensional active seismic-reflection survey using vibroseis. The vibroseis data provide a medium-resolution overview of the subsurface architecture including continuous reflection intervals and major discontinuities. Parts of the vibroseis survey were re-investigated using an electric vibrator to evaluate the potential of this environmental friendly seismic source. Extracted refraction data allowed to calculate a velocity model for the shallow subsurface. Additionally, passive seismic data were collected prior and during times of active surveying in the wider study area; linear data was used to optimise the station spacing for the area set-up and for the acquisition of seismic data perpendicular to the active survey. “Passive” area data were used to gather 3D insights. Geological interpretation of the various seismic reflection and refraction data integrated with subsurface knowledge from boreholes documented a major impedance contrast in the shallow subsurface caused by a prominent unconformity between Palaeozoic basement rocks covered by soft, partly consolidated Upper Cretaceous sediments. The soft-sediment cover effectively dampens surface-induced sounds in the target depth. This hampers the quality of subsurface imaging but is considered as beneficial for the operation of the ET in the Palaeozoic basement. With the collected passive seismic data, the main directions of surface generated noise and its denudation with distance from the respective sources can be identified.

Technology critical elements (TCEs) are widely understudied in aquatic systems. Many unknowns particularly are linked to the mechanistic understanding of TCE transport mechanisms in contrasting river systems. In this work, we aim at characterizing the colloidal vs truly dissolved TCE concentrations in three contrasting rivers in Germany (Rhine, Neckar and Danube) by comparing two filtering meshes (0.45 vs 0.02 µm). The seasonal component of such transport is also investigated based on monthly collections of water samples in 2023. TCEs were analysed via external calibration at the ICP-MS (iCAP series, Thermo®). Results suggest that each river has a different load on TCE concentrations, of which the colloidal transport differs even within the Rare Earth Elements and Yttrium (REEY) list. The seasonal influence is compared to water discharges and temperature ranges. These results provide further understanding of the watershed dynamics and can help identifying relevant processes that determine the unknown aquatic transport and fate of TCEs. This information can be used for developing scenarios for potential risk assessment of anthropogenic discharges from both stable and/or radioactive origin in surface aquatic environments in Germany.

Acknowledgements:

This work was funded by the Federal Ministry of Education and Research (BMBF) and the Baden-Württemberg Ministry of Science as part of the Excellence Strategy of the German Federal and State Governments. The authors also acknowledge the extensive contribution of the Landesanstalt für Umwelt Baden-Württemberg (LUBW, Germany) and the Amt für Umwelt und Energie (AUE, Switzerland) for the collection of water samples.

Iron oxide and hydroxide minerals are widespread in many aquatic environments and as such, can determine the fate of several metals of concern. Their role on metal mobility is generally studied under controlled conditions using synthetized materials. However, natural systems are complex and present a wide range of conditions, which may release metals differently to laboratory settings. In this study, we aim at understanding the mobility of geogenic, technology critical elements such as vanadium, nickel, cobalt, niobium, and tantalum from black sand sediments. These sediments from the OIB volcanic environment of the Canary Islands are the product of weathering and erosion of relatively geologically recent, ultramafic volcanic rocks composed of basanitic, phonolitic, nephelinitic and, locally, melilitic lavas and tuffs, sources of mafic heavy minerals deposited as a placer. The sediments were extracted through magnetic separation, characterized via XRD and SEM-EDS techniques, and further processed with a series of parallel selective extractions following widely applied protocols. Desorption kinetics during the extraction procedures were also investigated in order to understand the efficiency of the protocol for such sediments. Total element concentrations were quantified via XRF and LA-ICP-MS, whereas dissolved concentrations were determined via ICP-MS. Our results point towards contrasting selectivity during the extractions and different iron oxide mineral fractions in which these metals are bound. This information has a broad application for the potential environmental risk of metal mobility in aquatic systems.

Acknowledgements:

This work was funded as part of the Excellence Strategy of the German Federal and State Governments.

The GCI Rohrpassivsammler (tube-installed passive collector) is an innovative measuring device that uses the accumulation of water contaminants onto collector materials for integrative monitoring of varying concentrations, even for trace substances over long periods of time. The precise and adjustable flow and substance-specific calibration allow for a high level of sensitivity and quantitative evaluation of the collection results.

The patented measuring principle can be used with all water sources. The device has been successfully tested at production wells (installed in a bypass) and with treated wastewater, for the detection of explosives, industrial chemicals, and pharmaceuticals. Currently, applications for the detection of PFAS, Monochlorobenzene, and Lead are prepared.

In the latest design, concentrations are measured at short time intervals using substance-specific (bio)sensors, e.g. for Valsartan and Valsartanic Acid. A special design for installation in filter sections of groundwater monitoring wells is being developed which measures the concentration in-situ instead of pumping water to the surface. This design was successfully tested for detection of NSO Heterocycles. Future development is aimed at applications for surface water.

Quality and operation parameters are recorded digitally and wirelessly transmitted from the field for online access and visualisation.

Research and development are the Berliner Wasserbetriebe (BWB), the Fraunhofer Institute (IZI-BB), the Federal Institute for Materials Research and Testing (BAM), the Technical University of Applied Sciences Wildau (TH Wildau) and the Institute for Bioprocessing and Analytical Measurement Techniques (IBA). Development was funded by the German federal government (ZIM) and the state of Brandenburg (BIG ILB).

The role of clay colloids in facilitating or hampering the transport of cationic contaminants, such as heavy metal cations or radiogenic nuclides, in groundwater is well established. However, it is unclear whether this phenomenon occurs with positively charged organic contaminants to the same extent.

Laboratory column studies were conducted on water-saturated quartz sand for investigating the influence of colloids on the transport of metoprolol (MTP), a β-blocker with an acid dissociation constant (pK_a) of 9.6, under varying pH and ionic strength conditions. The experiments were carried out at pH 3, 6, and 11, with sodium concentrations of 1 and 100 mmol L^–1. Experiments were conducted with and without 0.5 g L^–1 Na-montmorillonite colloids (diameter: 100–1000 nm). The results show that the presence of colloids increases the transport velocity of MTP, particularly at pH 6 and low sodium concentrations, indicating colloid-facilitated transport as the primary mechanism. Upon reducing the pH, the magnitude of colloid-facilitated transport decreases, but the bimodal breakthrough curve still suggests some co-transport of MTP. At pH 6 and high sodium concentration (100 mmol L^–1) and pH 11, where MTP is predominantly uncharged, the presence of montmorillonite did not significantly impact the transport of MTP.

These findings highlight the dependence of MTP transport on the existence of clay colloids, salt concentrations, and the speciation of the contaminant determined by water pH. Thus, considering these variables is crucial for accurately predicting the mobility of positively charged organic contaminants in groundwater.

Groundwater in Niger represents an essential resource for survival in remote areas far from the Niger River and a reserve in areas where access to surface water is secured as in Niamey itself. The monitoring of this resource offered as a part of the technical cooperation with the Niger Basin Authority NBA enabled to obtain data on groundwater quality and observe changes in groundwater levels over the last decade. The monitoring targeted the three main aquifers existing in the area: the alluvial aquifer, the Continental Terminal aquifer and the fractured basement aquifer. Several boreholes in the first and second aquifers show high concentrations of NH₄, NO₂ and heavy metals. The boreholes belonging to the third aquifer show concentrations of NO₃ considerably exceeding the WHO recommendation value between 100-1500 mg/l making this resource unfit for water supply. Reasons behind these excessive levels were mainly explained through the direct discharge of wastewater which is common in the Sahel region into the underground. However, the increased concentrations of NO₃ in some wells during the rainy season imply a source in the unsaturated zone which mobilizes the nitrate during the infiltration.

In addition to nitrate, elevated concentrations of heavy metals such as arsenic and cadmium were detected in the basement aquifer proving the possible infiltration of contaminants from the top layers.

These results show that the monitoring tools offered within the technical cooperation framework enable to detect and trace the contaminants. however, they alarm the authorities to meet measures to protect this resource urgently.

The project “Groundwater Quality Monitoring Network Improvement 2021/2022” aimed to assess and improve the groundwater quality monitoring network of the Environmental Agency of the State of Brandenburg, Germany. This comprised six major steps:

1. Developing a catalogue of criteria for verifying the suitability of monitoring wells for representative groundwater sampling and for fulfilling specific reporting duties of the Environmental Agency (considering best practices)
2. Assessing the currently active monitoring wells regarding the suitability criteria
3. Reviewing the monitoring network in each groundwater catchment area regarding its capability to fulfil the different reporting duties
4. Identifying deficits in the network and researching further existing suitable monitoring wells in focus areas, e.g. from the Environmental Agency’s water level monitoring network or from district authorities’ networks
5. Testing the researched monitoring wells on site
6. Suggesting locations for constructing new monitoring wells where no suitable wells exist

A total of 936 active monitoring wells have been assessed. These results have been aggregated for 63 groundwater catchment areas as basis for the deficit analysis. 10 focus areas have been identified for researching and testing existing monitoring wells and for suggesting new sites.

One major project outcome is a three-page factsheet for each catchment area including detailed information on land use, hydrogeology and available monitoring wells as well as statistical analyses of the monitoring well distributions and their suitability. It also contains a prioritised list of measures (adding existing wells to the network, high and low priority new locations) to implement in the next years.

Soil moisture is a key metric to assess soil health. Water held in the shallow subsurface between soil particles enables various biogeochemical and hydrological processes indispensable to soil functions. Potential soil moisture deficit may rise the irrigation demands, which further exacerbates the stress on the water supply. The changes in soil moisture can impact climate, further amplifying the climatic anomalies and intensifying extreme weather events. Thus, understanding soil moisture and its dynamics over time are of broad scientifical interest and practical implications.

Despite the vital importance of soil moisture, it still lacks sufficient means to properly assess the parameter at a regional scale, which is an essential research dimension for addressing practical issues in the agricultural and environmental sectors.

Ambient noise seismology provides new possibilities to infer subsurface changes in a real-time, non-intrusive, and cost-effective manner. In this study, we map the temporal variations in soil moisture for the great Alpine region and the Italy peninsular with ambient seismic noise. It is the first time that the seismic method has been applied to map water resources at a regional scale using an ordinary national seismic network set-up. The seismic method helps in bridging the resolution gap between current pointwise (e.g., tensio-, electrical- and neutron-meter) and global (e.g., satellite-based remote sensing) investigations, providing complementary information for both scientific research and public decision-making.

The waterworks Briesen supply drinking water for the city of Frankfurt (Oder). The catchment of the waterworks is dominated by monoculture pine forests (Pinus sylvestris). Several forest-hydrological studies found that groundwater recharge under pine forests is lowest in comparison to other forest types. Hence, the question arose if forest restructuring could contribute to secure the drinking water supply of the region in the context of climate change and decreasing groundwater recharge.

Site classes of the forestry mapping were researched for all relevant forest restructuring areas. The Ministry of Environment of the State of Brandenburg published a recommendation of tree species mixtures which are suitable for the local conditions and for resisting climate change. Based on this recommendation, five tree species were selected. The tree mixture was set as percentage of these five tree species for each forest site class in the catchment.

The groundwater recharge below five tree species was calculated in a soil-water-balance model separately. Then the groundwater recharge was calculated for the forest site classes based on the percentage tree composition of each site. Finally, several scenarios of forest restructuring were developed, considering complete and partial restructuring as well as climate change. The resulting distributions of groundwater recharge were assigned as boundary conditions in a groundwater model.

The simulations with the groundwater model show that forest restructuring can increase groundwater recharge compared to current forests by 20 - 30 % and reduce the groundwater level decline and catchment expansion which is expected in the context of climate change.

The waterworks Lindau (Zerbst) are an important part of the interconnected system of drinking water supply in the region of Magdeburg, Saxony-Anhalt, Germany. The pumped water is exclusively fed by groundwater recharge. Measured groundwater heads show a continuous climate-induced decline of more than 3 meters for the last 50 years independent of waterworks management.

As basis for strategic planning of future waterworks management and optimization of the monitoring network, groundwater model based studies with climate projections were carried out. For this purpose, an approx. 1,200 km² transient groundwater flow model was set up. The present recoverable groundwater resources and their development in the catchment area until the year 2100 were modelled under changing climatic conditions. The underlying climate scenarios (RCP 2.6, RCP 4.5 and RCP 8.5) are based on the current state of global and regional climate research.

Available climate projections were statistically evaluated for the model domain. A bias correction for precipitation and evapotranspiration was applied and groundwater recharge was calculated transiently for each projection up to the year 2100 using a soil water balance model. This revealed a wide range of potential changes in groundwater recharge. The change ranges from about -35% to +50% by 2100 compared to the 1975-2020 period. The wide range results from high uncertainties of projected precipitation and spatial as well as temporal distribution patterns of precipitation.

The investigations show that in the long term further considerable changes in groundwater resources and hydrodynamics in the catchment are to be expected.

The Luneplate in Bremerhaven consists largely of nature reserves and bird sanctuaries. The soils have a thick alluvial clay horizon. Climate change threatens the region through seasonal heavy rain events, but also through the drying out of clay soils and the spread of saltwater inland due to rising sea levels. The region has traditionally been primarily agricultural, and in the northern part there is an economic area that will be complemented by a carbon-neutral GreenEconomy Park.

The planners of the new business park want to take various measures, including the use of excess rainwater, the creation of compensation areas and infiltration basins to drain surface water. This should also prevent the organic-rich alluvial clay from drying out, reducing the risk of higher CO2 release. This pilot project on the Lune Plate will explore, as part of the Interreg Blue Transition project, how the region can be made more climate resilient through targeted groundwater management measures that are already planned, as well as new measures such as infiltration wells. Infiltration wells can reduce saltwater intrusion and dissipate heavy rainfall. A high-resolution 3D groundwater model is used to simulate the effects of these measures and estimate their impact on climate resilience. The aim of the project is to enter into a dialog with investors and project managers in order to realistically assess the impact of measures and make a meaningful contribution to climate resilience.

The groundwater is a main issue in sustainable development of the Sinai Peninsula, Egypt. Because of extensive groundwater abstraction, the Quaternary coastal aquifer system in the study area is now facing a serious salt water intrusion problem. Seleem (1996) has developed a saltwater intrusion numerical model by using MOCDENCE software which is developed by Sanford & Kinikow (1985). He found that the saltwater intrusion increases the salinity of groundwater in the wells over time. The isohytal map of Sinai Peninsula also shows that the isohyetal contour lines increase towards the northern direction in the Northern Province of Sinai peninsula where the annual rainfall rate is 104.7 mm/year at El-Arish station and 304.1 mm/year at Rafah station.

In the presented study, we suggest a network of rainfall harvesting units to collect the amount of high intensity rainfall water from the cities in the study area. The harvested rainfall water could be injected in the frame of a managed aquifer recharge (MAR) project into the calcareous sandstone (Kurkar) aquifer to attenuate the salinity of this aquifer and to prevent the progress of freshwater-saltwater interface.

For the suggested scenario, the SEAWAT software is applied to simulate the three dimensional variable density groundwater flow and solute-transport in the Quaternary aquifer system in the northern Sinai, Egypt. SEAWAT was developed by the USGS based on MODFLOW and MT3DMS packages. The numerical study with the SEAWAT software allows to investigate the potential impact of MAR on the movement of freshwater-saltwater interface in the study area.

The study area, Erbil Central Sub-Basin, is located within the foothill zone in the stable shelf tectonic unit of Iraq (northern Iraq) on the Arabian plate. Recently, groundwater demand has increased significantly due to insufficient surface water resources for agricultural, industrial, and domestic water uses depending on ever-increasing socio-economic development and population in the study area. Sampling studies were carried out in two different periods, May 2020 (wet season) and September 2020 (dry season), to determine the water quality in water resources located throughout the sub-basin. For this purpose, a total of 30 samples, including 27 groundwater wells, and 3 wastewater samples from channels, were collected and analyzed. The general hydrochemical analysis indicates that overall well water quality is suitable for drinking purposes except where elevated NO₃, COD, and BOD5 concentrations are found. Most trace metal analysis results (except for Fe) in wells and wastewater channels show that they are below the permissible limits (0.3 mg/L) from IQWS (2010) and WHO guidelines (2011). The results of the factor analysis for the wet and dry season hydrogeochemical indicate that the first five and six-component extracted have eigenvalues>1 and correspond to approximately 94.844 and 96.26 % of the total variance, respectively. The factor analysis indicated that groundwater quality in the wet and dry season are significantly associated with anthropogenic pollution sources such as leaching from soil layers, cesspools wastes, industrial wastes, and agriculture activities rather than natural, geogenic processes such as reverse ion exchange, the weathering of carbonate minerals from geologic formations outcropping throughout the Erbil Central Sub-Basin.

The Kallar Kahar area falls in the sub-Himalayas. The structural geometry of the area has been assessed using geological mapping and structural analysis. At the surface the study area comprises of the rock units ranging in age from Precambrian to Pliocene with several major unconformities. The Precambrian Salt Range Formation is exposed in the form of diapiric intrusions. The strike slip Kallar Kahar Fault (KKF) controls the structural fabric of the area. It is a NW-SE trending structure characterized by an overall transpressional tectonics with a right lateral strike slip component. An en echelon pattern of NW-SE trending folds, a back thrust and a couple of fore thrusts occurs in the immediate south of the Kallar Kahar Lake. These thrusts are out of sequence thrusts cutting up section the thrust sheet of the Salt Range Thrust (SRT). The fore-thrusts represents a relatively younger phase of deformation than the back thrust as the former cross cut the later one. These folds and faults formed as a result of transpression associated with a left step over along the KKF. The rigorous compressional structures in the southeastern portion of the mapped area, and a clear discontinuity on the Landsat images are in line with the presence of a left step over along the KKF. The restraining along this stepover during ramping along the SRT, resulted in salt diapirism in the area. The KKF is believed to have formed to accommodate the variable stresses generated during the differential propagation of the SRT’s thrust sheet.