Central Europe is emerging as a new fire region, with climate change increasing the likelihood of forest fires. In contrast to “classical” fire regions, such as the Mediterranean, little is known about Earth surface dynamics following fires in Central European upland forests. In August 2022, a 13-hectare fire burned a spruce forest disturbed by a wide-spread bark beetle infestation in Harz National Park. We monitored the site at roughly six-month intervals, comparing burned and unburned areas using unoccupied aerial vehicles equipped with multispectral, thermal, high-resolution RGB, and LiDAR sensors. Derived orthoimages, 3D point clouds, and canopy height were employed to estimate standing deadwood, succession indicators such as fractional vegetation cover, microclimate regimes, and small-scale morphological changes. We additionally collected soil samples with different burn severities, including soils associated with charcoal kilns that repesent legacies of past land use, to better understand post-fire nutrient and pollutant dynamics over time. We particularly focused on the point-source contamination by polycyclic aromatic hydrocarbons, which are considered toxic to organisms, including human health, and that could be measured in soils sampled over time. We found a dynamic setting associated with fire severity, subsurface tunneling, and the long-term legacy of granite landscape evolution, collectively affecting post-fire mass movements, vegetation recovery, and pollutant loads. Here, we present first insights into deadwood breakdown, vegetation succession, surface erosion and soil property changes, to bridge the knowledge gap between well-studied fire-prone regions and emerging ones like Central Europe and to provide base-knowledge for future research and management strategies.

Human impact has developed into a major external forcing control on Earth’s environmental and geological processes, yet our understanding of the magnitude of its impact and evolution, particularly in (peri-)urban settings, is still limited. This study investigates the anthropogenic impact of the metropolis Vienna on its peri-urban environment in floodplain archives of the Danube River. By applying sedimentological, geochronological and chemostratigraphic methods, we aim to characterise the interplay between upstream human interventions and local river dynamics, and to identify and evaluate the geological signal of the Great Acceleration since the 1950s downstream of Vienna.

The study area is located in the National Park Donau-Auen, where minimal direct human intervention allows quantifying the human stratigraphic fingerprint and testing event-based dating using (artificial) radionuclides in an alluvial setting. Flood deposit ages were successfully determined combining radiogenic nuclide concentrations (¹³⁷Cs, ²³⁹Pu, ²⁴⁰Pu, ²³⁷Np, ²³³U, ²³⁶U), field sedimentological methods, and historical records. Preliminary results reveal three distinct sedimentation periods reflecting upstream human interventions. The first phase (1870 – 1954) aligns with extensive river channelization leading to rapid erosion of mid-channel bars and backwater aggradation. The second phase (1954 – 1991) shows laterally extensive and thick sandy flood deposits from fast and undamped sediment transport through the straightened riverbed during extreme events. The final phase (1991 – 2002) is characterized by the thick, silty, and seemingly structureless flood deposits, interpreted as remobilized sediment from barrier lakes since the construction of the nearby hydro-power station Freudenau in 1997.

Human mining activities have been reshaping landscapes for millennia, but their pace and scale have accelerated substantially on a global level. As a result, mining has become a key indicator in the Anthropocene discourse. Moreover, increasingly complex landforms, shaped by both natural and anthropogenic forces, are emerging, resulting in hybrid landforms that necessitate a reevaluation of traditional geomorphological approaches. The study focuses on mining landscapes in mountain regions, which are under growing pressure due to increasing resource demands. Understanding past landscape development is crucial for addressing current and future socio-environmental challenges.

In this context, the Harz Mountains were selected as study area, as they represent one of the oldest and most significant historical mining regions in Central Europe. Using a multi-proxy environmental-historical approach, the study investigates when, how, and to what extent human activity has modified the relief landscape with a case study from the St. Andreasberg Mining District in the Oder and Sieber Valleys. An interdisciplinary conceptual approach was developed to address hybrid landform assemblages considering geological-geomorphological aspects in the light of the socio-cultural setting. The approach outlines the spatio-temporal interconnections between mining and its associated energy systems, the historical water management and charcoal production, and considers aspects such as the emergence of the global metal trade, economic and political systems as well as knowledge networks during the Early Modern Period. The study is part of the LEHA-project „UNESCO World Heritage Upper Harz Water Management: Landscape Change and Energy Use in the Harz in the Anthropocene“ financed by zukunft.niedersachsen.

The former German Democratic Republic (GDR) conducted extensive hydrocarbon exploration in northern Saxony-Anhalt, the Altmark, a region geologically characterized by numerous salt dome structures. Drilling operations reached depths of up to 4,000 meters and an average depth of 2,000 meters, often penetrating the entire Cenozoic and Mesozoic strata.

Micropaleontological surveys were conducted at 423 drill sites and produced valuable stratigraphic and paleoenvironmental data. Once disclosed, these reports were scanned and archived in a conservation effort, remaining as non-OCR PDFs, limiting accessibility and modern analytical use. The digitization and standardization of these archived reports have now been completed, resulting in a unified dataset comprising approximately 1,600 unique, quality-controlled taxonomic and petrographic markers. Where possible, taxonomic names have been verified against the World Register of Marine Species (WoRMS). This dataset forms the basis for ongoing statistical analyses, including cluster and co-occurrence studies, to explore distribution patterns and relationships within the micropaleontological record.

The project aims to refine the stratigraphic framework of the region and provide supplementary paleoenvironmental indicators. High-resolution, high-density stratigraphic data can help refine existing subsurface models and improve ties between borehole and seismic data. A comparative assessment against the GDR’s lithological-paleogeographical maps (scale 1:500,000) is planned to evaluate consistency and identify areas for model updates. With the digitization phase completed and statistical evaluations in progress, this study highlights the untapped potential of historical exploration data for modern geoscientific applications.

Ostracoda (Crustacea) are important proxies of palaeolimnological analysis, especially in Quaternary continental sediments. They allow tracing temperature changes, salinity, oxygen availability, productivity, pollution, or turbulence to name only a few environmental factors. Autecological tolerances allow the reconstruction of habitats and environmental parameters, often in a quantitative way. Despite there is a long and intense history of ostracod research in Germany, no compilation is available since Klie (1938).

Within a new research project, we intend to compile all information about Recent and Quaternary Ostracoda of Germany and began in the Baltic Sea and the East, i.e. the area of the former GDR. Plenty of material and many publications are available: Thousands of micropalaeontological slides with picked Quaternary ostracods and foraminifera from the former exploration company Erdöl-Erdgas Gommern, similar numbers of slides from the Museum für Naturkunde Berlin filled by Kurt Diebel und Erika Pietrzeniuk in the 1960ies to 1990ies and many more at museums and geological surveys of the eastern Federal states plus several dozens of widely scattered papers on Recent and Quaternary ostracods provide a huge and unique dataset to make use of. This dataset will be palaeoecologically and biostratigraphically analysed and made accessible to the public within a searchable database. We expect distinct progress by using documented association data for better characterizing habitats, climatic changes and biogeographic patterns. Furthermore, the biostratigraphic values of ostracod species will be improved.

We kindly ask colleagues for information about hidden collections or documentations of German Quaternary ostracods to enlarge our database.

The South Caspian is one of the largest oil and gas-producing regions in the Caspian Sea, containing most offshore fields and major prospective reserves of Azerbaijan, Turkmenistan, and Iran. Effective development and exploration of these resources require a detailed understanding of Quaternary sea bottom sediments—their composition, microfauna, stratigraphy, thickness, and physical properties. This is essential not only for improving geological exploration efficiency and safety but also for solving engineering and geological challenges associated with field development.

This study presents results from a comprehensive analysis of data obtained from offshore wells in the South Caspian. We integrated geological and geophysical datasets, including seismic surveys, lithological descriptions, and paleontological studies.

Our findings are of practical importance for addressing geological and geoengineering tasks in the region, which are complicated by features such as mud volcanoes and active sedimentary dynamics. By analyzing the upper sedimentary layers, we gained critical insights into the geological structure, sedimentary architecture, and dynamic processes shaping the region’s offshore fields.

The research underscores the value of applied micropaleontology in synthesizing diverse data to develop a detailed understanding of subsurface conditions. This approach enhances exploration strategies and supports the safe and efficient development of offshore oil and gas fields in the Caspian Basin.

The former Layla Lake Area in Saudi Arabia were covered by a couple of lakes which dried up until the 1980th, caused by man-made irrigation processes. The running DFG founded project „Zwischen der Westwindzone und der Innertropischen Konvergenzzone: ein hochaufgelöstes Paläoklima- und Paläoumweltarchiv holozäner Sedimente der Layla-Seen in Saudi Arabien“ investigates the lake sediments by applying a multi proxy approach to reconstruct the lake history and link it to climate changes during the Holocene. The applied methods include sedimentology, geochemistry, hydrology, diatoms, palynology and micropalaentology. Here we present the results of the ostracod analysis of the master section L-2-1. We identified at least four species (Pseudocandona spp., Cyprideis torosa, Darwinula stevensoni and Heterocypris salina), which indicate different water qualities, probably based on changing water levels and development of a phytal zone. Additionally, we used the ostracod valves of two selected species for stable isotopes analyses. Although the pollen association indicates the increasing aridisation of the Arabian peninsula during the late Holocene, the ostracod assemblages do not follow this trend and point to a water column which seems to be independent from the general climate trends. More intense investigations of the population structure the detailed ostracod shell features and a comparison with the four other sections of the Layla Lakes are needed for further details and will be carried out in near future.

Situated in a tectonically active region, the Peloponnese is susceptible to large earthquakes, submarine landslides and volcanism, hazards capable of generating destructive tsunamis. Despite this, the triggering mechanisms and recurrence intervals of such events remain poorly understood. Coastal lagoons serve as valuable geoarchives, preserving the sedimentological footprints of such high-energy wave events. These fragile environments are highly sensitive to environmental and sea-level changes, making them ideal for reconstructing coastal dynamics.

Within the framework of the MULTI-MAREX project, this study investigates the sedimentary archives of Vatika Bay to identify traces of past marine geohazards. A multi-proxy approach was employed to analyze the sediments, including grain size, magnetic susceptibility, inorganic geochemistry and microfaunal composition.

Sedimentary records across the study area exhibit features of extreme wave deposits. These include abrupt changes in sedimentation with distinct coarser layers intercalated within muddy lagoonal and alluvial deposits, reflecting low-energy background sedimentation interrupted by an extreme marine incursion event. Sharp basal contacts and fining upwards sequences further support the marine origin of the deposits. Preliminary geochemical and foraminiferal analyses reveal delimited elevated concentrations and ratios for marine indicators, alongside sharp increases in foraminiferal assemblages, dominated by species typical of coastal environments.

Nevertheless, the shape and preservation potential of these deposits are influenced by the complex interplay between local tectonics, coastal morphology and lagoonal dynamics. Overall, this work provides new insights into the paleoenvironmental evolution of the coastal lagoon and its extreme wave event history, contributing to our understanding of marine geohazards in Greece.

The Mediterranean Sea has experienced numerous tsunamis, triggered by earthquakes along the Hellenic and Calabrian arcs, submarine landslides, and volcanic eruptions in Italy and Greece. Nonetheless, patterns related to the timing, frequency, intensity, and dominant triggering mechanisms of these events remain poorly understood. The Maltese archipelago is vulnerable to tsunamis from multiple directions in the surrounding Mediterranean seascape. Malta differs from other Mediterranean coasts because no onshore tsunami-related deposits other than coastal boulders have been reported. However, coastal boulder deposits are difficult to date or link to known events. To fill this gap, our study presents the first identification of sand-grade sediments in northern Malta (L-Aħrax Peninsula) interpreted as tsunami deposits. Found within karst pockets (natural solution hollows in limestone), these shelly sands overlie terra rossa soils and are well-preserved due to the relatively protected nature of the karst hollows. The work provides the first description of tsunami sediments in Malta, characterizing their granulometric properties, sedimentary structures, and micro-faunal assemblages, all indicative of a marine origin. Notably, the presence of the foraminifera Amphistegina lobifera, a species introduced to the Mediterranean after the 1869 opening of the Suez Canal, provides a relative age constraint. The close spatial association of these sands with large coastal boulders supports a tsunami origin. These findings offer the first robust evidence of tsunami deposits in Malta and highlight the utility of karst features in preserving such records. They also expand understanding of tsunami hazards in the Central Mediterranean, with implications for regional coastal risk assessments.

Deltaic sandstone deposits of the Berriasian Bückeberg Group in the Lower Saxony Basin are potential geothermal reservoirs. Detailed sedimentological and ichnological analysis of subsurface expressions to underpin the paleodepositional interpretation as deltaic have yet to be presented, but are crucial to understanding reservoir quality and distribution.

Deltaic intervals in two cores were logged with a focus on sedimentological and ichnological character, e.g., grain size, sedimentary structures, lithological accessories, bioturbation index (BI) and ichnological elements. Facies are grouped into facies associations.

Two types of deltaic successions are identified (1) wave-dominated deltaic deposits and (2) storm-dominated deltaic deposits. Wave- and storm-dominated deltaic facies associations display coarsening-upward successions, variable bioturbation intensities (BI 0–5) and host overall low-diversity, facies-crossing assemblages with marine ichnological elements. Wave- and storm-dominated deltaic successions differ in sedimentological and ichnological expression. Wave-dominated deltaic deposits display abundant wave-ripple lamination, normal and inverse graded mudstone beds, and overall moderate to elevated bioturbation intensities (BI 3–5). By contrast, storm-dominated deltaic deposits display abundant hummocky cross-stratification and fewer burrowed beds (BI 2–5).

Reservoir quality and distribution differs in studied wave- and storm-dominated deltaic successions. Wave-dominated deltaic successions display sandstone beds with abundant biogenically reworked mudstone beds. Sandstones in storm-dominated deltaic deposits display fewer and less burrowed mudstone beds. Reservoir distribution in purely wave-dominated deltas is expected to form relatively smooth shoreline protrusions, whereas storm-dominated reservoirs are associated with subaqueous channel deposits. Results highlight the importance of sedimentological and ichnological facies analysis to improve geothermal reservoir exploration in the Bückeberg Group.

Coastal boulder deposits (CBD) along the Greek coastlines have long been considered indicators of past extreme-wave events, such as tsunamis. In this study, we aim to refine previous volume and mass estimates of CBD and reassess their possible tsunamigenic origin. To achieve this, CBDs were analyzed using advanced calculations for hydrodynamic conditions, that not solely focus on masses, but include LiDAR-scanned geometrical shapes and variations of coefficients that rely on their physical properties.

Therefore, we studied CDB near the Bay of Vatika by using built-in smartphone LiDAR sensors. In combination with rock density analysis, their masses were obtained. The CBD are distributed along a ~600 m-long coastal stretch. The largest boulders (≥38 t) are located on bedrock near the shore. Smaller boulders (>100 kg) are located up to ~200 m inland, partly embedded in sandy sediments and covered by vegetation, and were found up to 6-7m above sea level. It is indicated that the sandy sediments underneath boulders were transported as suspended load and deposited alongside them. Orientations of >330 measured CDB’s longest axes dominated in NNW-SSE direction. Rock pools indicate overturning during transport, imbrications and accumulations in clusters indicate extreme-wave events as transport mode. OSL analysis is intended to provide a chronology and confirm prior age estimations for the CBDs (~910-1150 yrs. BP).

With reference to the existing literature, we found that former volume analyses on CBDs in the study areas significantly overestimated the masses, thus we provide new data to refine calculated wave parameters and tsunami wave heights.

Understanding past climate dynamics is critical for improving projections of future climate change (IPCC, 2022). The Last Interglacial period (126–115 ka), characterized by elevated global temperatures and sea levels, serves as a valuable analog for anticipating future climate scenarios. While this period has been extensively studied in some areas, the Arabian Peninsula and adjacent Indian Ocean region remain comparatively underexplored (Rovere et al., 2023). Coastal sediments at Ras ar Ru’ays in northeastern Oman, situated 1–3 meters above present sea level, are likely linked to the Last Interglacial (Decker et al., 2024) and offer promising insights into past sea-level behavior. This study examines these deposits, which consist of interbedded sand and silt layers and a shelly coastal bar. A total of six sedimentary profiles and nine thin sections were investigated, both in the field and through micro facies analysis, to characterize lithofacies, diagenetic features, and depositional settings. Stratigraphic cycles were identified from the profiles to assess the role of climatic and sea-level fluctuations. Results indicate that the outcrop represents a barrier-lagoon system, an environment shaped by dynamic coastal processes and variable energy conditions tied to changes in sea level and climate.

Shear-wave tomography models of the upper mantle below intracontinental Central Europe are indicative of a thermally very heterogeneous lithosphere-asthenosphere system. Low shear-wave velocities indicate the presence of a deep 1300 degC isotherm and thus thick (200 km) lithosphere in the SW North Sea and the Paris Basin, which contrasts with a shallower (< 120 km) lithosphere-asthenosphere boundary observed across the ECRIS and much of the British Isles. These major, long-wavelength depth fluctuations of the thermal boundary layer are locally superposed by a number of smaller-scale thermal anomalies situated within the lithospheric mantle (such as the Eifel mantle thermal anomaly). In an earlier study, we discussed how present-day density and strength variations in the mantle lithosphere may affect the distribution of earthquakes in this intraplate setting. With this new contribution, we focus on discussing potential ages of those upper mantle thermal anomalies in an attempt to delineate their roles in the geological past. The overlying crystalline crust and sediments provide us with records of a multiphase tectonic and sedimentary evolution that extends from Paleozoic to Cenozoic times. To better understand upper mantle controls on crustal deformation phases, we investigate spatial correlations between upper mantle temperature variations as derived from shear-wave tomography models with major crustal structures of known geological age and setting. We will also discuss existing correlations in the light of thermal field variations across the lithosphere produced by numerical simulations of conductive heat transport.

Mixing of siliciclastic-carbonate sediments is a common occurrence throughout geological time, that typically records contemporaneous deposition of pure carbonate and siliciclastic end-members. These heterolith develop in microscopic compositional to mesoscopic stratigraphic scale, under the influence of allocyclic (sea-level fluctuations, climate, tectonism) and autocyclic (depositional dynamics) controls. This study examines an approximately 15m-thick, laterally extensive (over-100km) mixed siliciclastic-carbonate heterolithic unit, positioned between the Banaganapalle siliciclastic and Narji Limestone from the Mesoproterozoic (approximately 1.3–1.2Ga) lower Kurnool Group, India. Sedimentological and stratigraphic observations of the mixed siliciclastic-carbonate heterolithic unit reveal three facies associations, namely (1) glauconitic sandstone interbedded with clayey siltstone, (2) mixed calcareous shale-siliciclastic-carbonate heteroliths, and (3) carbonate-clast conglomerates with calcareous shale and thin bedded limestone. The facies associations represent transition from storm-dominated middle to inner shelf depositional environment to open-marine distal shelf setting, punctuated by episodic high-energy events (e.g., storms, tsunamis). Two primary sediment-mixing modes are identified: (i) stratal mixing-microscopic bed to lithofacies scale-driven by sea-level oscillations and high-energy events, and (ii) compositional mixing at microscopic scale-driven by in-situ mixing of transported nearshore siliciclastic with subtidal carbonate mud. This mixed siliciclastic-carbonate heterolithic unit helps to bridge the transition from the intracratonic siliciclastic rift system of the Banaganapalle Formation to the passive margin carbonate platform of the Narji Limestone. Intracratonic rift-related faulting, triggered by post-Columbia breakup, likely induced rapid subsidence, facilitating widespread marine transgression and the heterolith deposition. This mixed siliciclastic-carbonate heterolith serves as an archive to understand the tectono-sedimentary evolution, preserving the complex interactions among tectonism, sea-level changes, and sediment supply.

The calcarenites of the Reitbrook Formation represent a promising mid-depth geothermal reservoir in the North German Basin. A comprehensive re-evaluation of borehole data from the hydrocarbon industry indicates that these units were variably truncated by the Paleocene transgression and exhibit significant variations in depth and thickness. To better constrain their spatial distribution and reservoir geometry, a 3D seismic dataset was reinterpreted, focusing on salt structures, faults, and key stratigraphic horizons.

The results indicate that (i) inversion tectonics ceased during the Campanian, whereas salt structures continued to evolve independently during the Maastrichtian, and (ii) each salt structure, together with its associated marginal trough, experienced a distinct developmental history that directly influenced reservoir configuration. Salt movement shaped the reservoirs during both synsedimentary and post-sedimentary phases. Synsedimentary salt tectonics, in particular, led to the formation of minibasins, localized highs, and differential subsidence. These processes controlled sediment thickness, facies distribution, and early reservoir compartmentalization. In contrast, post-depositional salt movement deformed pre-existing stratigraphy, generating folds, faults, and structural traps that affect fluid compartmentalization, vertical migration, and pressure regimes.

This study emphasizes salt tectonics as a key control on the geometry and heterogeneity of the Reitbrook calcarenites. Accurate reservoir models, geothermal assessments, and sustainable energy development require a thorough understanding of the temporal interplay between salt deformation and sedimentation. Understanding the salt-tectonic evolution of the basin is essential for the development of exploration strategies, such as identifying thick, well-preserved zones, deeper areas with elevated reservoir temperatures, and fault zones that enhance permeability.

This study investigates bioclastic carbonate contourite deposits from the Eifelian–Frasnian of the Tafilalt Platform (Morocco) to enhance the understanding of carbonate sedimentation under bottom-current influence. In contrast to the classical bi-gradational contourite facies model, which is based on continuous deposition of fine-grained siliciclastics, these contourites reflect intermittent accumulation, resulting in thin, condensed successions with abundant hiatuses.

Five facies associations are identified, recording pelagic sedimentation and contourite deposition on a contourite terrace, an inclined section of the uppermost slope of northern Gondwana shaped by a shifting water-mass interface. Deposition was primarily controlled by oxic, clear-water bottom currents, as evidenced by bioturbated limestones with hydrogenetic ferromanganese nodules and low organic-carbon contents. In contrast, episodes of anoxic bottom-current activity are recorded by interbedded organic-rich coquinas featuring well-preserved traction structures, minimal bioturbation, and syngenetic pyrite framboids.

The large-scale depositional architecture includes an abraded surface, an alongslope contourite channel, and a small mounded drift. Microfacies analysis reveals frequent alternations between suspension settling, winnowing, bedload traction, dynamic sediment bypassing, and concomitant seafloor cementation. Coquinas composed of planktonic and nektonic organisms are integral components of bi-gradational sequences, which also feature lag deposits of carbonate intraclasts, conodonts, and ferromanganese nodules draping hardgrounds.

This high-resolution record provides a unique opportunity to investigate the spatial and temporal variability of bed-scale contourite features in conjunction with drift-scale depositional architecture—both shaped by palaeoceanographic processes during the Devonian greenhouse climate.

South Papua is a complex geological region, particularly due to its position as a structural extension of the North Australian sedimentary basin. In this region, the Southern Papua Basin developed along with
intensive tectonic activity, one of which is the influence of the Digul Fault.

This study aims to evaluate the relationship between the fault system and the formation and evolution of basin stratigraphy in the Asmat region and its surroundings. Based on the interpretation of regional geological, lithological, and geophysical data, it is known that the Digul fault acts as the main structural boundary that controls sedimentation from the Miocene to the Recent. This fault activity triggered the formation of graben and half-graben systems that accommodated the accumulation of clastic and carbonate sediments in fluvial to deltaic environments.

This study also indicates that the existence of these structures can influence the potential for hydrocarbon traps and active tectonic dynamics in South Papua.

Keywords: South Papua, Digul fault, sedimentary basin, Asmat, Australian tectonics, hydrocarbons

The Upper Rhine Graben (URG) hosts one of the most continuous sequences of unconsolidated late Cenozoic sediments in central Europe. Its location between the northern European inland and alpine glaciation during the Pleistocene provides the opportunity to investigate the interactions of tectonic and climatic control on sedimentation and erosion processes. In 2020/21, a new continental drilling campaign was carried out by the Hessian State Agency for Nature Conservation, Environment and Geology (HLNUG) near Riedstadt-Erfelden in the northern part of the URG to obtain information on the development of the graben system and its infillings, complementing results from previous drillings. This study presents geochronologic data derived from combined luminescence dating approaches. Preliminary results using optically stimulated luminescence (OSL) and infrared-radiofluorescence (IR-RF) are supplemented with infrared-stimulated luminescence (IRSL), post-infrared-IRSL (pIRIR) and infrared photoluminescence (IRPL) signals. The latter represents an innovative approach, utilising a potentially non-destructive and non-fading signal from K-feldspar. For the first time, we applied the multiple elevated temperature (MET)-pIRIR-IRPL single aliquot regenerative dose (SAR) protocol suggested by Kumar et al. (2021) to fluvial samples. Furthermore, the results are compared to ΔIRPL signals derived from the same protocol.

References

Kumar, R., Kook, M., Jain, M., 2021. Sediment dating using infrared photoluminescence. Quat. Geochronol. 62, 101147. https://doi.org/10.1016/j.quageo.2020.101147.

Dry conditions in the Atacama and Andean forearc region, prevailing since the early Miocene, vary across geographic gradients and pluvial episodes. Areas of northern Chile experienced inherently different surface processes (e.g. evaporitic, periglacial, glacial), influencing fluvial system evolution and sediment signal propagation. We compare five Chilean alluvial fan sub-environments of varying aridity to assess sedimentary signal preservation. These sub-environments include 1) the hyper-arid, debris flow-dominated Chilean coastal fans that are largely incising and Late Quaternary in age; 2) the hyper-arid core Atacama with Quaternary fans impacted by evaporitic processes and paleolake level alterations; 3) the megascale Precordillera fans that date back to the Miocene; 4) fans in the arid transition from the upper Rio Loa valley to the High Andes that show evidence of periglacial processes and volcanic events; 5) finally, the semi-arid fans on the Altiplano of the western Andes that show evidence of Pleistocene glacio-fluvial aggradation and interfingering with lake sediments in addition to periglacial and volcanic events.

To investigate signal propagation, we assess the timing of terminal fan surface aggradation through terrestrial cosmogenic nuclides and luminescence dating, while documenting landscape processes. We also explore stratigraphic fan architecture, through numerical landscape evolution modeling, sedimentary bedding analysis, and ground-penetrating radar (GPR). Using this multi-method approach, we aim to disentangle how climatic and tectonic drivers shape sediment production and propagation in Andean forearc fan evolution. Results are preliminary, following multiple field campaigns, the latest in March 2025.

On Lanzarote (eastern Canary Islands), several valleys were dammed by volcanic activity during the Quaternary, creating closed sedimentary basins locally known as “vegas”. Since their formation, these basins have acted as natural sediment traps, preserving layered sequences of aeolian dust, volcanic material, and colluvial slope deposits. The sediments are characterized by an alternation of pale carbonate-enriched layers (PCLs) and reddish clay-enriched layers (RCLs), reflecting cyclic sedimentation patterns.

In this study, we apply principal component analysis (PCA) to geochemical (XRF) and mineralogical (XRD) data to differentiate sediment sources and assess the provenances of dust inputs. The PCA results show a clear geochemical and mineralogical pattern within the profiles, enabling interpretations of sediment origins and depositional dynamics. PC1 separates silty, quartz- and Zr-dominated dust from clay-rich inputs, linked to kaolinite, and basalt-derived material enriched in Fe, Ni, and Zn. These local materials are also separated from V and Rb by PC2. The distinct clustering of quartz, kaolinite, and K-feldspar points to contributions from multiple North African dust source areas. This geostatistical approach provide the basis for further investigating dust source areas and linking the findings to regional palaeoclimatic developments across the Canary–North Africa domain.

Saharan dust input is a well-known phenomenon worldwide but especially concerning landscapes around the Mediterranean Sea and on the Canary Islands since the largest dust source areas on earth are located in the northern African continent. Its effects have been imprinted in several geoarchives and are especially well known from aeolianite archives. These coastal dune archives typically form in dependence of changes in sea level and are comprised of pale coloured carbonate sands, intercalated by reddish silty layers, which we call paleo surfaces. They were heavily influenced by, among others, dust imprint from the northern African continent. The aim of our research project is hence to conduct detailed analyses on those layers to reconstruct local and supraregional environmental conditions during the last glacial.

In view of the good temporal resolution over the last glacial our sites on Lanzarote (Canary Islands), Cabo Roig (SE-Spain), Formentera and Eivissa (Balearic Islands) and Sardinia offer best conditions to answer the following research questions, building on each other: (i) What are site-specific characteristics of the dust enriched layers and what information about the local environmental conditions are stored within our geoarchive? (ii) Are there differences or systematical similarities in terms of quantities and admixture of dust material when comparing the different paleo surfaces within a single site/profile? (iii) Can we identify distinct source areas of dust as well as dominating dust pathways ? (iv) Are we able to correlate the different sites from the Canary to the Tyrrhenian basin and what supraregional patterns are deducible?

The Layla Lakes are a series of karst lakes located in central Saudi Arabia (300 km S of Riyadh). Their sediments were exposed in the 1980s due to groundwater drawdown. These finely laminated lacustrine sediments likely consist of seasonally alternating carbonate and sulfate layers and preserve a high-resolution archive of Holocene environmental variability in central Saudi Arabia.

Two sedimentary successions capture the transition from a more humid early Holocene to increasingly arid conditions after ~4000 cal BP. The humid phase (7500–6200 cal BP) is characterised by laminated micritic carbonates with the average sedimentation rate ~2.7 mm/year and alternating loosely and tightly packed layers. Loosely packed layers are rich in biogenic compounds, whereas tightly packed layers lack visible biological content. This alternation likely reflects summer–winter seasonality, forming seasonal laminae. Fossil-rich layers were potentially formed during summer, and biogenically poor layers during winter.

The arid phase (4400–2600 cal BP) is marked by a higher sedimentation rate ~5.1 mm/year with alternating thick gypsum and thin carbonate layers, and pollen assemblages typical of semi-desert vegetation. Gypsum layers are devoid of organic remains and likely formed during hot, dry summers with intense evaporation, whereas carbonate layers contain biogenic material (ostracods, algae, diatoms, and gastropod fragments) and may reflect cooler, wetter winters. This seasonal deposition regime appears to have persisted until recent times.

These sedimentary patterns reflect a long-term Holocene shift toward increased aridity and seasonality. Additionally, the rhythmic recurrence of carbonate and sulfate layers and variations in fossil content indicate sub-Milankovitch (centennial-scale) climatic cyclicity.

Understanding the role of fire in past interglacial ecosystems is crucial for interpreting long-term vegetation dynamics and early human-environment interactions. Here, we investigate macroscopic charcoal (150–500 µm and >500 µm size fractions) preserved in palaeolake sediments from Bispingen (Lower Saxony, Germany), which cover the entire Eemian Interglacial (marine isotope stage (MIS) 5e; ~125.000 years before present). The goal of this study is to reconstruct local fire activity during the early Eemian and assess whether its causes were natural or anthropogenic, including potential links to early hominin presence. Results will be compared with other Eemian sites in Central Europe, particularly Neumark-Nord, to contextualize the findings both regionally and palaeoecologically (e.g. through comparison with existing pollen data).

Samples were taken continuously at 2-cm intervals from the early Eemian part of the palaeolake sediment succession and subsequently wet-sieved into different size fractions. The extracted charcoal fragments were counted and morphologically assessed using a digital microscope. Preliminary results show a low abundance of macroscopic charcoal, especially of the smaller size fraction, suggesting that fires were not widespread near the palaeolake. Dominant charcoal morphotypes are yet to be identified. Special attention is thereby given to methodological consistency, including challenges related to charcoal distribution across size fractions and morphological variability. Influx per year and cm² is calculated, allowing the comparison to other Central European sites.

Overall, the results of this study contribute to the broader understanding of fire as an ecological, climatic and potentially cultural driver during the Eemian Interglacial.

The exact number, extent, and chronology of Middle Pleistocene ice advances into northern Central Europe are still debated. To gain insight into the timing of the Elsterian to Saalian ice advances, 25 samples for feldspar single-grain luminescence dating were taken from five different Saalian ice-marginal positions and Elsterian tunnel-valley fills in northwestern Germany. The sampled Elsterian glacigenic sediments comprise subaqueous fans and deltas that were deposited in glacial lakes and underfilled tunnel valleys during ice-margin retreat. The preliminary luminescence ages indicate a correlation with Marine Isotope Stage (MIS) 12. However, the sampled sediments are partly in saturation. This is likely due to subglacial erosion of older sediments. The analyzed Saalian deposits mainly consist of glaciofluvial fans, characterized by sandy sheetflood deposits, alternating with coarser-grained, multilateral, or multistorey channel bodies. Preliminary luminescence ages suggest several ice advances during MIS 8 and MIS 6.

The (meta-)sedimentary succession of the Northern Vosges and adjacent scarce outcrops of crystalline basement in the Palatinate Forest are located in a key position at the transition between the Mid-German Crystalline Zone (MGCZ) and the Saxo-Thuringian Zone of the Central European Variscides.

Their geotectonic positions have been discussed widely in the past; while the crystalline rocks of the Palatinate are typically assigned to the MGCZ, the Northern Vosges are considered to be part of the Saxo-Thuringian Zone sensu strictu. Detrital zircon grains reveal different age spectra, showing a wide range of source areas and supply routes from source to sink. Maximum depositional ages in the Northern Vosges range from the Neoproterozoic to Cambrian (ca. 580 - 550 Ma) in the Villé unit (Southern succession) to Upper Devonian/Lower Carboniferous (ca. 360 Ma) in the Bruche unit (Northern succession) and the adjacent Palatinate Forest. The maximum depositional ages of the detrital zircon populations are in general agreement with biostratigraphic subdivisions of the respective units.

The zircon spectra of the Villé unit are very similar to those derived from the Saxo-Thuringian Zone, indicating sediment supply from the North Gondwana margin, whereas the spectra derived from the Bruche unit and the Palatinate Forest point to a close affinity to the MGCZ. This is additionally supported by a U-Pb concordia age of ca. 370 Ma estimated for the Albersweiler Gneiss, during this and previous studies. Our new results have consequences for the interpretation of the evolution and plate tectonic reconstruction of the Central European Variscides.

Der Hohe Hagen-Basalt intrudierte im mittleren Miozän in ca 70 m mächtige oligozäne Sande und Tone. Nach bisherigem öfter zitierten Modell handelt es sich um einen dreiseitig von Störungen kontrollierten "Vulkanstumpf" von ca 150 m Durchmesser und unbekannter Tiefe unter einem postulierten Vulkanbau. Mit fortschreitendem Basaltabbau zeigte sich ein anderes Bild, das jetzt dargestellt wird durch Kombination einer Diplomkartierung mit kürzlich wiedergefundenen Tachymeter-Meßtischaufnahmen, alle aus der Endphase der Basaltgewinnung 1980-84.

Die detaillierte Kartierung der räumlichen Orientierung der Basaltsäulen zusammen mit der Raumlage aufgeschlossener Basalt-Sand-Kontakte zeigt die erwartete ideale Orientierung sodaß mit ihr auch die Lage unbekannter Kontakte gut bestimmbar erscheint. Die Intrusion hat danach die Form einer in NNE-SSW-Richtung gestreckten Schüssel mit einer flachen Sohle, ca 100 x 200m messend, die mit wenigen Grad zum Fuß des Westhanges einfällt. Dort ist im Norden der Kontakt durch das tiefste Abbauniveau nicht mehr erreicht worden. Hier kann also der Förderkanal der Lopolith-förmigen Intrusion liegen.

Plattiger, wasserreicher Basalt des Kontakts zeigt oft ellipsoidische, extrem geplättete und gelängte Blasen. Die entsprechend des X-Linears abgeschätzten Fließrichtungen sind ebenfalls gut verträglich mit einem Förderzentrum am und unter dem nördlichen Fuß des Westhanges.

Ein N-S-streichender, vermutlich störungskontrollierter Förderkanal verlangt nach einem Nachweis von Störungsbewegungen im Tertiär, der mit bisher untersuchten stratigraphischen Indikatoren uneindeutig blieb. Die regionale Bedeutung eines kartierten synmagmatischer Vertikalversatz in einer N-S-Zone am SE-Rand der Intrusion ist offen.

Mit der Definition einer Lopolith-förmigen Intrusion und einem N-S-verlaufenden Fördergang reiht sich der Hohe Hagen nun in mehrere gleichartige benachbarte mittelmiozäne Basaltintrusionen ein.

The base Quaternary in northwestern Lower Saxony is characterised by an undulating surface that is intersected by a complex network of buried tunnel valleys. Their development is mainly associated with the Elsterian glacial stage. The Quaternary sediments contain minable sand and gravel deposits, and host most of the groundwater reservoirs. The incision depth of tunnel valleys is a relevant parameter for the countrywide ongoing search for a suitable site for radioactive waste storage. To date, comprehensive information for the base Quaternary in Lower Saxony is available from a 30-year-old contour map, but more recent data are available. Thus, a revision of the base Quaternary as a 3D geological model is essential to support strategies for sustainable resource extraction and land use.

The new 3D model covers approximately 11,800 km². It has been compiled in Aspen SKUA® and is based on a broad dataset: The existing contour map of the base Quaternary has been combined with more recent data, especially seismic data (2D/3D) and extensive borehole data. Additionally, we considered information from geological cross sections and regional 3D models. Several previously unknown tunnel valleys were discovered. Seismic data proved to be extremely valuable to map their course and geometry over tens of kilometres. Our model indicates that erosion depths may reach up to -415 m NHN, which is more than 50 m deeper than previously assumed.

The 3D model will be available via the NIBIS® mapserver (https://nibis.lbeg.de/cardomap3). Work on the 3D model will be continued for other parts of Lower Saxony.

The youngest Maastrichtian sedimentary unit in the North German Basin (NGB) is represented by the Reitbrook Formation. Historically significant as a hydrocarbon target, these marine deposits are currently under evaluation for mid-depth geothermal potential. Yet, they remain poorly characterized, with limited understanding of lithofacies variability, depositional environments, and stratigraphic evolution.

This contribution presents preliminary results from a comprehensive sedimentological study of a 140-meter-thick core section of Upper Maastrichtian beds, recovered from the central-northern sector of the NGB in Lower Saxony. Emphasis is placed on lithofacies analysis and the identification of depositional sequences, complemented by existing petrophysical data to assess vertical variations in reservoir quality.

Two lithofacies associations dominate throughout the succession: i) whitish, frequently flint-bearing, sandy marlstones, containing considerable amount of terrigenous component, likely deposited in inner to mid-shelf settings; and ii) glauconite-rich and siliciclastic-dominated “greensand” beds deposited in a nearshore environment, showing high porosity and permeability values. Both associations differ markedly from the classic bioclastic limestones of the Reitbrook Formation described in the literature, have not been previously documented, and are thus interpreted as proximal equivalents.

Sedimentary sequences of various orders are identified within the succession. Particularly, its basal portion comprises stacked small-scale sequences, typically within a 20-meter thickness, characterized by variations in sandy marlstone thickness and flint content, and bounded by glauconite-rich clastic beds. These cycles likely reflect the interplay between sea-level fluctuations and/or episodic pulses of sediment influx. Overall, the succession displays a pronounced regressive trend, with nearshore greensands increasingly dominating upward, correlating with enhanced reservoir potential.

The Rhenish/Ardenne Massif (RAM) is one the most “emblematic” Variscan structures located north of the Alps. Intraplate uplift affected the RAM during the Plio-Quaternary along with other Palaeozoic massifs located in the alpine foreland. However, its cause(s), shape and rates are still poorly understood and therefore remain debated. This was, until recently, mainly due to a lack of reliable ages for uplift markers, such as the Quaternary terrace staircases along deeply incised valleys of the Rhine, Moselle and Meuse as well as their main intra-massif tributaries. Several studies based on numerical dating methods (i.e., cosmogenic nuclides, ESR, OSL…) have shed new light on these questions by assigning numerical age estimates on key levels of fluvial terraces or cave levels related to phases of regional base-level stability.

This contribution compiles all chronological data produced over the last twenty years. Plio-Quaternary incision rates are accordingly reconstructed. A similar trend is reported throughout the RAM with a peak of incision occurring during the Early or Middle Pleistocene and matching the main massif-wide geomorphological marker. However, age control reveals a significant time lag (>250 ka) between the south-eastern and north-western RAM margins. High incision rates onset is consistently older along the Rhine/Moselle and tributaries than along the Meuse and tributaries. This key finding is well in line with the hypothesis arguing for a wave of uplift migrating northward throughout the RAM. It also supports regional tectonic causes for uplift (i.e., upper-crustal stress transfer from the Alps to their foreland) rather than more local ones.

Geological mapping in the vicinity of Düsseldorf, Germany, has been carried out systematically for over 100 years, starting with a mapping campaign by the Prussian Geological Survey in the 1920s. Today, geological mapping is performed by the Geological Survey of North Rhine-Westphalia and published at a scale of 1 : 50 000. In addition, 3D models are created from the collected data and all data are made available to the public via online portals free of charge.

We present new geological map data for the surface and at major sedimentary hiatuses for Düsseldorf and adjacent areas. The map of the surface geology allows a detailed representation of Pleistocene to Holocene sedimentary processes. While fluvial sediments of the Rhine River predominate in the Rhenish lowlands, the hilly landscape of the Bergisches Land is widely characterized by aeolian sediments of the Quaternary cold phases. The geological map of the pre-Quaternary surface provides a detailed depiction of Oligocene marine sedimentation. The geology of the top of the pre-Permian bedrock depicts marine to paralic sedimentation in the Devonian and Carboniferous. Furthermore, it clearly shows the tectonic structures that were created during Variscan orogenic folding and post-orogenic normal faulting. In addition to these map layers, cross sections were created for depths of up to 3000 meters. A spacing of only 2 km between these cross sections allows detailed three-dimensional imaging of the subsurface.

Gypsum of cap rocks from Upper Permian (Zechstein) salt structures in Luneburg and Othfresen, both Northern Germany, were investigated for geochronological, mineralogical-geochemical, stable isotopic (δ³⁴S and δ¹⁸O of the SO₄^2- ion; δ¹⁸O of the hydration water of gypsum) and petrographic characteristics. Cap rocks are formed during salt diapirism and groundwater contact (dissolution, re-precipitation, transition of evaporite minerals). For dating the precipitation of gypsum, Optical Stimulated Luminescence (OSL) was used (1).

First uncorrected age estimates range from 0.4 ka ± 0.3 ka to 7.1 ka ± 2.8 ka for the Luneburg samples and for the gypsum pit Othfresen, respectively. The age estimates represent the lower detection limit of the method for these samples. Some individual subsamples yield uncorrected age estimates from 14.4 ka ± 2.8 ka to 114 ka ± 25 ka for Luneburg samples and 9.3 ka ± 5.0 ka up to > 394 ka for Othfresen gypsum. Age estimates of these subsamples could be part of an unbleachable OSL-component or it could reflect the timing of different solution/ precipitation phases of gypsum crystals during alteration.

δ³⁴S- and δ¹⁸O- values of the sulfate ion average 11.5 ‰ (VCDT) and 12.1 ‰ (VSMOW), representing a typical Upper Permian Zechstein signature. In contrast, δ¹⁸O- values of bulk gypsum average 5.8 ‰ (VSMOW), indicating the influence of isotopically light hydration water from the transformation of Permian anhydrite to gypsum. These results are in line with the young ages derived from OSL and the petrographic observations.

1: Mahan, Kay (2012): Quaternary Geochronology 10: 345-352

The salt-cored Asse-anticline is located in the Subhercynian Basin and was formed during the Late Cretaceous phase of tectonic shortening. The salt anticline contains a former salt mine, in which low- and intermediate-level radioactive waste was disposed during the 1970s. During more than hundred years of mine history and the planning for the retrieval of the radioactive waste in the last 15 years, a large amount of geological and geophysical data were acquired. The interpretation of a 3D seismic data set in combination with new well data recently provided insights into the local structural framework.

We discovered that the Asse salt anticline developed around an intersection of two systems of normal faults formed prior to the Late Cretaceous. The NW-SE trending fault system strikes parallel to the anticline and is located in the vicinity of its crest. Another E-W-trending fault network crosses the eastern part of the anticline and causes an along-strike change of its geometry. Although the exact timing of the faults is unclear, they indicate two separate phases of tectonic extension. During the subsequent phase of tectonic compression, the normal faults in the anticlinal flanks partly became inverted.

The structural trends of the normal faults are also recognized in the intra-salt layers. Here, the dominant trend of the fold axes is NW-SE, which is interrupted by E-W-striking folds in the Eastern part of the salt mine. Thus, we suggest that salt deformation is mostly a relict of the extensional phases and was only partly overprinted by tectonic shortening.

The polymict Upper Rotliegend conglomerate of the Schadewalde 2/75 borehole, Saxony-Anhalt (Germany) represents a high-resolution archive of erosion and sediment supply along the northeastern Permian Saale Basin. The clasts are embedded in a matrix-rich, poorly sorted conglomerate, representing proximal alluvial fan deposits of the Upper Rotliegend (Havel Subgroup). Microscopic investigations of core samples from the 1407–1440 m depth interval, reveals a broad spectrum of clast lithologies, including milky quartz, various plutonic, volcanic, and metamorphic rock fragments. This lithological diversity suggests a heterogeneous provenance and reflects a complex depositional history. Our study focusses on characterising the range of clast composition and textures to unravel the provenance.

Although the dataset is still in progress, a coarse graphically textured pegmatitic biotite quartz-monzonite to monzodiorite clast already illustrates the informative potential of individual grains. Microscopic investigation reveals graphic intergrowth of quartz and K-feldspar, perthitic K-feldspar, altered plagioclase, chloritised biotite, and late diagenetic chlorite-filled micro-fractures. These microstructures suggest crystallisation from a volatile-rich melt upon slow cooling, followed by potential greenschist-facies deformation, and/or hydrothermal alteration, predating erosion, transport, and deposition of the clast. Subsequent diagenetic fluid overpressures may have triggered micro-hydrofractures during basin subsidence, facilitating chlorite precipitation. Although representing only a single clast, its characteristics suggest a nearby Permian exposure of highly evolved granitic plutons, providing insights into the source area, basin-margin transport, and alluvial-fan processes. However, its provenance assignment remains tentative, as it cannot yet be considered representative for the entire conglomerate.

An increase in fluorine concentration significantly enhances rim growth rates between periclase and wollastonite, as previously reported by Franke and Joachim-Mrosko (2022). However, the mechanisms responsible for this acceleration, as well as the quantitative relationship between volatile content and rim growth dynamics, remain only partially understood. A more detailed understanding of these processes is critical for our understanding of the role of volatiles in metamorphic and metasomatic reactions.

To address this, we conducted high-p-T experiments at 1000 °C and 1.5 GPa for 20 minutes, with fluorine contents ranging from 1 to 2 wt%. For example, at 1 wt% fluorine, rim growth reached an overall thickness of approximately 50 µm. Building on a previous study (Franke and Joachim-Mrosko, 2022), our preliminary results suggest a linear increase in rim growth rate between 0 and 1 wt% fluorine. However, at fluorine concentrations exceeding 1 wt%, the slope of this linear trend seems to suddenly decrease. Moreover, fluorine is observed to accumulate at the rim–wollastonite interface, indicating a coupled transport of fluorine and MgO.

The reduced growth rate above 1 wt% fluorine may be attributed to a microstructural transition from a layered to a more lamellar rim microstructure, which likely modifies grain and phase boundary properties and thus affects rim growth kinetics.

Reference:
Franke, M., & Joachim-Mrosko, B. (2022). Am. Mineral.

In the mafic lower crust, clinopyroxene and plagioclase are among the main rock-forming minerals. Both are considered to be strong and to deform by brittle mechanisms at dry lower crustal conditions. However, at fluid-present high-pressure conditions both are highly reactive, transforming to omphacite, (clino-)zoisite and garnet, thus forming weaker eclogite.

Recent studies have focussed on plagioclase breakdown reactions and their effect on rock weakening. However, field observations on Holsnøy, Norway, indicate ductile deformation of coarse-grained clinopyroxene in the mafic lower crust, reflected by bending of the granulitic foliation. This study focusses on the strain accommodating processes of the granulitic clinopyroxene at an early stage of eclogitisation. Representative samples of deformed weakly eclogitised granulite were analysed using scanning electron microscope, electron back-scattered diffraction, and electron probe micro analysis.

Microstructural analysis revealed the formation of garnet-lamellae along the clinopyroxene-cleavage. Initial bending of this anisotropic clinopyroxene is accommodated by the development of micro-en-echelon cracks at a high angle to the cleavage. Micro-cracks are traced by garnet with similar composition as the lamellae, suggesting that both formed at identical conditions. With ongoing strain, cracks start to link and evolve into micro-shear zones, systematically widening with strain. This leads to the nucleation of amphibole and a second clinopyroxene with higher magnesium-concentration, facilitating further macroscopic bending of the clinopyroxene. Late static eclogitic overprint suggests that micro-shear zones form at an early deformation stage. Our investigations show the complex interplay of brittle and ductile processes on a microscopic scale during macroscopically ductile flow.

In convergent settings, continental and/or oceanic mafic rocks are subducted to great depths where they experience high pressures and temperatures and transform to eclogite. Accompanied mineral transformations subsequently result in mechanical changes and in density variations. In the last decades, numerous studies targeted eclogite and aimed at quantifying its mechanical behavior as well as characterizing strain weakening processes, yet the mechanisms driving strain localization remain unclear. We combine field, microstructural, petrographic and geochemical data to investigate the origin of strain localization at eclogite-facies conditions. Our study examines a shear zone containing two distinct eclogite-facies assemblages. The host-rock eclogite is composed of clinopyroxene, garnet, zoisite, amphibole, quartz, kyanite, and rutile, within which sigmoidal enclaves are enriched in zoisite, hornblende, and garnet. Protolith assemblage calculations suggests these enclaves originated as plagioclase-rich gabbro cumulates and were initially weaker than the surrounding gabbro. However, their sigmoidal geometry within ultramylonitic eclogite implies they were stronger during shear zone evolution. The ultramylonitic eclogite shows a fabric dominated by euhedral clinopyroxene, with grain boundary melt traces and junctions indicating deformation via melt-assisted grain boundary sliding. In contrast, enclave microstructures are dominated by elongated zoisite and amphibole aggregates that deform through dislocation creep and diffusion-mediated grain growth. These findings indicate a strength inversion during high-pressure metamorphism where initially weaker enclaves became stronger, concentrating stress at lithological boundaries and thus promoting strain localization in the weaker eclogitic matrix. Our results underscore the significance of compositional heterogeneities on strain localization at high pressures.

Magnetite frequently forms during low-temperature serpentinization of mantle rocks and is hence a common mineral in serpentinites at oceanic core complexes. Deformation of serpentinites is considered a crucial ingredient in many geodynamic processes and yet poorly understood. Here we explore magnetite microstructures in order to test their suitability to track deformation in serpentinites.

The Atlantis Massif at the mid-Atlantic ridge is an oceanic core complex where a ~1.25 km long core (U1601C) was drilled during IODP Expedition 399. Shipboard data of recovered samples show strong variations in macroscopic parameters such as alignment, thickness and spatial distribution of magnetite aggregates. Using electron backscatter diffraction (EBSD), we analyse how microstructural parameters such as grain size, grain shape and alignment and crystallographic preferred orientation (CPO) link to the macroscopic parameters .

Four representative samples with a distinct macroscopic foliation intensity have been chosen and large area ESBD/EDX maps produced at 0.2/0.5 μm step size. Grain size is mostly <10 μm equivalent diameter. Long axes of individual grains tend to be (sub)parallel to the long axes of larger magnetite aggregates, irrespective of whether aggregates contribute to the main foliation or not. Magnetite CPO strength is variably strong and dominated by CSL3 twinning.

We will discuss the relation between macroscopic and microstructural parameters with regard to the development of the magnetite foliation and its possible relation to deformation.

Serpentinites are key players in subduction zones due to their unique mechanical behavior, which affects tectonic and seismic activity along the subduction interface. A persistent question is the mismatch between experimentally deformed serpentinites—typically showing brittle or brittle-ductile features—and naturally deformed ones, which display dominantly ductile microstructures. Debate also continues over whether deformation in antigorite-bearing rocks is driven by crystal plasticity, dissolution-precipitation, or both. Additionally, few studies have addressed deformation in hydrated or partially dehydrated serpentinites (with metamorphic olivine and clinopyroxene) at (ultra)high-pressure conditions.

To explore these issues, we analyzed a strain gradient zone within the Zermatt-Saas meta-ophiolite, focusing on antigorite and olivine deformation under conditions relevant to intermediate-depth earthquakes and mantle wedge exhumation. Low-strain samples show olivine-diopside veins from brucite-antigorite dehydration, with weak antigorite CPOs and evidence of twinning. Deformation localizes around olivine veins, where olivine shows a B-type CPO but no internal strain. With higher strain, antigorite forms a strong foliation, its CPO intensifies, and olivine experiences folding, boudinage, and CPO strengthening. High-strain zones exhibit mylonitic fabrics, intense antigorite foliation, and transposed olivine veins forming isoclinal folds. S-C’ foliations and pressure shadows develop with fine-grained olivine fibers and olivine-diopside mixtures.

These observations reveal a transition from brittle-ductile to fully ductile deformation in fluid-rich serpentinites, governed by both dissolution-precipitation and dislocation creep. This study offers rare insights into the deformation behavior of serpentinites at depth.

Oceanic core complexes are a common feature along slow-spreading mid-ocean ridges. Serpentinized mantle rocks are exposed at the seafloor in the footwall to large-scale detachment faults. While it is likely that the exposed and rotated footwall has experienced deformation, it is unclear how internal footwall deformation is accommodated by the ultramafic rocks. One example of such an oceanic core complex is the Atlantis Massif at the Mid-Atlantic ridge (30° N) drilled by International Ocean Discovery Program (IODP) Expedition 399. Site U1601 provides the unique opportunity to understand any deformation recorded in serpentinized mantle rocks over >1.2 km depth.

To better understand the depth distribution of deformation and the associated deformation mechanisms, we combine microstructure and crystallographic preferred orientation (CPO) analysis by means of Scanning Electron Microscopy techniques, Micro-X-ray Fluorescence Mapping and synchrotron high energy X-ray diffraction. Results show variable microstructures ranging from zoned mesh cells with no CPO, to foliated samples with a strong CPO of both serpentine and magnetite, to serpentinite samples exhibiting deformation microstructures like kinking, faulting and dissolution-precipitation. The origin of characteristic microstructures and CPOs, whether formed due to serpentinization, deformation, or mutual interaction, will be discussed.

Quartz crystallographic preferred orientations (CPO), often reduced to solely inspecting the (0001) polefigure, are frequently used to deduce finite strain type, shear sense and deformation temperature of deformed rocks. While the direct dependency of CPO and deformation temperature can actually be rejected (Kilian & Heilbronner, 2017), a so-called opening-angle thermometer is still commonly applied. Using various datasets of natural quartz mylonites formed under different metamorphic conditions, we strongly suggest that a finite, steady-state quartz CPO is the result of mostly two independent, texture-forming deformation processes, dislocation glide (strain-dependent) and dynamic recrystallization by oriented nucleation and growth (stress-dependent). Those processes occur simultaneously and their relative contributions depend on factors such as strain rate, deformation temperature and grain boundary mobility, amongst others. In combination with flow kinematics, the contributions of both texture-forming processes determine the finite CPO. The quartz CPO features are at most only indirectly related to temperature and should not be applied as a thermometer. However, a useful application of quartz CPO includes usage as a simple proxy of rock rheology (i.e. flow at low or high stress conditions), mostly robust against post-kinematic annealing.

Kilian, R., Heilbronner, R., 2017, https://doi.org/10.5194/se-8-1095-2017

During Late Miocene magmatic activity, Elba Island was intruded by multiple magmatic complexes. In the north-eastern part of Western Elba, the rocks have undergone pyroxene hornfels metamorphism and ductile deformation due to the intrusion and following uplift of the 6.9 Ma Mt. Capanne monzogranitic pluton. Objectives of this study are preliminary detailed microfabric analyses of a metalimestone (diopside-bearing marble), a metacalc-silicate (wollastonite-bearing skarn) and a metachert from the contact aureole at the Spartaia and Paolina beach to present a first insight into the contact metamorphism-related deformation mechanisms. X-ray diffraction, electron backscatter diffraction, scanning electron and optical cathodoluminescence microscopy were applied, to quantify microstructures and crystallographic preferred orientations (textures). It was found that the metalimestones and metachert show significant microstructural deformation and strong texture that is correlated to the intrusion, uplift and exhumation of the Mt. Capanne pluton. The metalimestones show intensive simple shear deformation by grain shape preferred orientations, deformation bands, twinning, recrystallisation and textures. Some of the deformation features in the skarn cannot only be correlated to the intruding pluton but also to the metamorphic reactions by growth of the thermometamorphic mineral wollastonite. The very fine-grained metachert shows a polygonal microstructure and a homogenous texture throughout the fold hinge and limbs. From these first results, further detailed studies can be deduced and defining now a systematic sampling considering e.g. sample orientation related to folds, the metamorphic gradient within the contact aureole and non-metamorphic pendants in Eastern Elba to refine the metamorphic and deformation history at different scales.

Mineral reaction textures such as coronae are commonly observed features in metamorphic rocks and serve as valuable indicators for quantifying metamorphic processes. Their formation is typically controlled by pressure, temperature, chemical composition, as well as the presence/absence of fluids and their composition. While highly saline fluids have been reported from various metamorphic environments, their impact on reaction rim growth remains elusive.

In this study, we experimentally explored the role of fluid salinity on the formation of wollastonite reaction rims between quartz and calcite using a piston-cylinder apparatus. The starting material comprised a mixture of fine-grained calcite and coarse-grained quartz (95:5 by mass), along with 1 wt% fluid. Fluid composition was set at an XCO₂ of ~0.3 with variable CaCl₂ between 0 and 40 wt%.

Experiments involved two steps: (1) annealing at 1 GPa and 800 °C for ~2 days to promote recrystallization and produce a synthetic impure carbonate, followed by (2) reaction at 1000 °C for 24 hours to initiate wollastonite formation. Results reveal wollastonite rim formation on calcite surfaces at low CaCl₂ concentrations (0-6 wt%), while wollastonite growth on quartz surfaces has been observed at high CaCl₂ concentrations (up to 40 wt%).

We interpret our finding that fluid salinity affects solubility of minerals and therefore element mobility in grain boundary fluids, which in turn controls local mineral growth/dissolution recorded in metamorphic textures. Hence, the role of fluid composition in interpreting natural metamorphic microstructures provide potential for future studies.

While the dynamics of central European fluvial systems were originally controlled mainly by climatic changes, human impact has fundamentally altered the catchments’ sediment dynamics. During the Middle to Late Holocene, a transition occurred to anthropogenically controlled fluvial systems, which got stored in floodplain sediments as these record both past river dynamics and human activities (e.g., settling, mining, logging).

Since insights from the meso-scale rivers are largely lacking, two rhenian tributaries were studied with a higher (Kinzig river, Black Forest, Germany) and lower (Fecht river, Vosges, France) impact of mining and timber drift and raft. We use geophysical surveys, sedimentological investigations, luminescence dating, and geochemical analyses to study floodplain stratigraphies and heavy metal contaminations.

Our sedimentological data reveal distinct phases of floodplain accumulation (Kinzig: 0.1 mm/a for Late Pleistocene/Early Holocene till 9.00 ka, 0.3 mm/a for Mid/Late Holocene 9.00-0.82 ka, 1.1 mm/a for modern 0.81-0 ka). Additionally, floodplain sediment contaminations and historic land use seem closely related as suggested by the timing and rise in heavy metal concentrations (Kinzig: enrichment factors of Ba, Pb, Cu peaking at ca. 2.5, 4.0, 3.0). Preliminary results from the Fecht also point to increasing accumulation rates over a similar time span.

Hence, cross-referencing floodplain stratigraphy with land use history supports our understanding of a gradual shift to an anthropogenically dominated fluvial system. Said transition occurred in the Kinzig after human settlement in the Upper Rhine plain, finding higher anthropogenic impact on floodplains over the last ca. 2500 years as found in the unprecedented accumulation rates.

Peatlands are important long-term carbon sinks that also contribute significantly to water regulation. However, over the past centuries, many Central European peatlands have been heavily modified by human activity. One key consequence of these interventions is peat subsidence resulting from drainage and surface lowering. Understanding the extent and development of this process is essential for reconstructing long-term changes in wetland landscapes.

This poster explores peat subsidence over the last 250 years in two lowland regions: the Donaumoos fen in Bavaria and the Rhinluch fen in Brandenburg. Both areas were subject to major drainage efforts and canal construction beginning in the 18th centuries. Based on old maps from different time periods, we trace spatial and temporal patterns of surface change and land transformation. Therefore, contour lines were vectorised and interpolated into DEMs. Due to further calculations peat subsidence rate could be indentified (and show transitions). Intersection of the peatsubsidence with the spatial density of the ditches indicate the most intensive time period of human intervention on the peatlands.

The analysis investigates whether and how the development of peat subsidence differs between the two regions. While both have been significantly shaped by human interventions, the cartographic data allow for a comparative perspective on the dynamics of peatland transformation. Moreover, this approach provides a basis for estimating historical carbon losses associated with peat degradation—an essential step for understanding long-term environmental impacts.

The formation of fine-grained overbank deposits is, among other factors, linked to human-induced land cover changes and water management, such as mill dams, ponds and ditches. Therefore, floodplain sediments and architecture can provide information about past sediment dynamics. In former mining areas, the variability of risk element concentrations with the sediment depth is a valuable proxy for environmental conditions and anthropogenic impacts.

The study area is the 180 km² large upper and middle catchment of the Selke River, which is well-known for mining activities since the 13^th century. The Selke River is a typical river at the transition between the uplands of the Harz mountain range and the loess-dominated lowlands.

Based on archaeological and historical records, sites for drill core drilling and soil profiles were identified, representing floodplain characteristics upstream, in between, and downstream of known mining and smelting sites. The sampled sediments are analysed for grain size, radiocarbon ages from charcoal fragments, elemental concentrations, and slag.

Initial results indicate at least a biphasic nature of the overbank deposits, reflecting the onset of mining/smelting activities in the study area. In particular, changes in the risk element concentrations, the presence of slag fragments and their properties characterise anthropogenically affected sediments. The first radiocarbon ages date the earliest anthropogenically affected (e.g. polluted) sediments to the 10^th to 11^th century. In addition, variations in the risk element concentrations both vertically and horizontally within the cross-sections indicate intercalation with different phases of erosion and aggradation. Distinct changes in the grain size distribution support this complex floodplain architecture.

Severe flooding in July 2021 exposed Pleistocene Rhine River gravels (upper terrace) overlain by Erft River floodplain deposits near Erftstadt-Blessem, Germany. Though now inaccessible, the site provided an opportunity to investigate fluvial sculpting caused by natural fluvial processes and human interference. Preliminary cosmogenic burial dating places the Rhine gravels to 900-1100 ka, covered by <35 ka clayey sediments of a buried channel (optically stimulated luminescence, OSL, from quartz). Further OSL ages of ~1 ka in a sandy lens and ~0.4 ka in reworked floodplain loess represent early, anthropogenically-induced sediment redistribution.

Historical maps depict a pre-19^th century Erft meander close to our site and the buried channel. Despite subsequent anthropogenic channelisation, the 2021 flood caused backward erosion that mirrored this earlier routing. Striking geomorphological features (theatre-shaped gully heads, pipes) formed, potentially resembling plunge pool and seepage erosion (sapping), as typically occurring where discharge meets sudden elevation changes and lithological contrasts are sharp, such as found at our site.

To evaluate the role of such exotic erosional processes in landform formation, we conducted structural and morphometric analyses using Structure-from-Motion Multi-View Stereo (SfM-MVS) photogrammetry. Several gullies display features characteristic of sapping-dominated landscapes. At least one pipe could have predated the 2021 flood, as indicated by internal manganese incrustations; fallout radionuclide analyses are underway to test soil particle transport through these pipes.

This multi-method study aims to enhance our understanding of Quaternary fluvial dynamics and anthropogenic impacts in the Rhine-Erft region, and how both contributed to the specific post-flood erosional patterns found at Erftstadt-Blessem.

The floodplains of the rivers Echaz (3^rd order tributary of the Rhine) and Eger (3^rd order tributary of the Danube) in southern Germany were both heavily anthropogenically modified from the Middle Ages to early Modern times. Water pollution from the larger cities and the usage of water meadows are two important examples of human activities that are visible in the sediment, which ostracods and molluscs can provide more information about.

Actualistic studies of ostracods in central European rivers have confirmed that they are good indicators for documenting water turbulence and phytal zones as well as non-permanent water covers. With fossil assemblages thereby also the spatial extent of water bodies can be assessed. Water pollution by organic substances or heavy metals may be indicated and assessed by oxygen or heavy metal sensitive species. The frequency of aquatic and terrestrial gastropods, bivalves, and macrobotanical remains provide further information about the floodplain development, the palaeoenvironment, and the past land use.

In both colluvial and overbank deposits, taphonomic effects play an important role in the distribution of micro- and macrofossils. Transport can be detected by, e.g. disarticulation, fragmentation or abrasion of ostracod carapaces and mollusc shells. Although the springs of both Echaz and Eger derive from the Swabian Jura and are characterized by calcareous water, the overbank sediments often show dissolution, especially the thinner ostracod valves. Local changes in dissolution patterns can, however, also be used to indicate groundwater levels or the spatial location or proximity of a water body.

The Elster-Pleiße floodplain south of Leipzig has undergone significant hydromorphological changes over the past centuries, influenced by both natural processes and anthropogenic interventions. This study employs high-resolution LiDAR-based fluvial-geomorphological mapping (1x1 m resolution) and old maps analyses to reconstruct past river dynamics and identify shifts in channel morphology. Geomorphological mapping reveals an earlier, more dynamic floodplain characterized by meandering and anabranching channels, which transitioned into a system of stabilized, largely immobile watercourses. Comparative analyses of old maps spanning from the 16th to the 20th century indicate a gradual reduction in river sinuosity and lateral migration, coinciding with increasing human modifications such as mill races, timber rafting canals, and flood protection measures. Key transformations include the straightening of channels, floodplain aggradation, and the impact of open-cast lignite mining in recent centuries. The study highlights the complex interplay of climatic fluctuations, sedimentary processes, and anthropogenic activities in shaping the floodplain’s evolution.

Understanding these long-term dynamics provides crucial insights for contemporary river restoration and flood management strategies.

Systematic human intervention in wetlands has been taking place in central Europe for several centuries. The Donaumoos fen in Upper Bavaria, Germany, has been cultivated since 1788, resulting in the permanent loss of its natural state. The adjacent Danube River was straightened during the same period. This study presents a quantitative reconstruction over a 235-year-long time frame of the development of the natural Donaumoos fen and Danube River into a human-dominated landscape (anthroposphere). The selected quantitative proxies for the change in the socio-ecological system are the Donaumoos drainage ditch lengths and changes in Danube surface water area traced through the analysis of old maps. A multi-temporal series of old maps are used to document land reclamation in the Donaumoos and hydro-engineering activities in the Danube floodplain. A comparison of the quantitative data on the development of drainage ditch lengths with the state of research from written sources leads to the discovery of potential great transitions in floodplain and peatland changes and associated human drivers as well as consequences for society in the region. One phase of great transition with far-reaching human interventions spanned 1788 to 1794 and a second phase ran from 1907 to 1959. However, the phases of substantial transitions with river straightening, land reclamation and colonization were embedded in multi-decadal intervals of setbacks and socio-ecological stagnation. Regarding the future, an updated economic and ecological understanding of resources is difficult to implement for the Donaumoos because socio-ecological path dependencies present challenges for the sustainable development of the Donaumoos.

The southwestern margin of the Central Asian Fergana Basin is a tectonically complex region with a 500 million year record of sedimentation. Cambrian to Middle Carboniferous passive margin and carbonatic shelf sediments were intensively deformed by the closure of the Turkestan Ocean in the Late Carboniferous. After a period of uplift and erosion, a sucession of small Triassic-Jurassic nonmarine basins with a highly diverse and globally significant fossil record formed. Following repeated marine incursions in the Upper Cretaceous, the Fergana Gulf connected the eastern Peri-Tethys, Tethys, and Siberian epicontinental sea during major phases of global climate change in the Paleogene. Repeated convergence and uplift in the Neogene and Quaternary formed todays’ topography. Soviet 1:200,000 scale mapping in the 1950's was predicated on geosynclinal theory and failed to recognize the nappe architecture of the South Fergana Zone, leading to inaccurate ideas on basin configuration and paleoenvironmental reconstructions. Building on a field mapping campaign in 2007-2009, the core area of the Madygen Geopark is being remapped at a 1:25,000 scale by a combination of field work, remote sensing and geomorphological analysis. Together with newly logged profiles of the most important fossiliferous sucessions, the paleogeographic and paleoenvironmental history of the Madygen geopark is being reassessed.

The results will enable the reinterpretation of the voluminous fossil collections of the past six decades of paleontological research in terms of paleoecology, depositional environment and possible migratory pathways. Finally, the new geologic map will facillitate further research, educational and geotouristic activities at the Madygen Geopark.

The eastern margin of the Lepontine Dome represents an area of particular interest to understand the geodynamic evolution of the Central Alps. Here, the stack of the lower Penninic units underwent a syn- to post-nappe emplacement regional Barrovian metamorphism and was then exhumed forming a dome-like structure. This vertical ascension up to the present-day crustal levels was coeval with the intrusion and exhumation of the Gruf-Bergell system along the Insubric Line and was plausibly affected by buoyancy forces driven by a hot thermal perturbation. The uplift of these units involved the structurally higher Brianҫonnais Tambò and Suretta nappes, that, unlike the Lepontine Dome, did not experience a regional Alpine Barrovian metamorphism. Focusing on the contact between Adula and Tambò nappes, a transition from ductile to brittle deformation behaviour can be observed in the field, along with several kinematic indicators that point to a top to North-NorthEast directed shearing of the southern portion of the Tambò Nappe. The Forcola Line, that separates Adula and Tambò nappes across the Swiss-Italian border, represents the major tectonic lineament that express a syn-collisional orogen-parallel extension within a predominantly brittle regime, active since the Oligocene and directly related to the ascension of the dome. Within this intricated scenario we present several field evidence that will help to shed light on the geodynamic setting and evolution of this area, focusing on the structural relationships between Adula, Tambò and Gruf units and on the role of rigid bodies in the deformation and related metamorphism of the Tambò Nappe.

The Cima Lunga is a crystalline basement unit located in the Lepontine dome (Swiss Central Alps). It is formed by paragneisses, orthogneisses, layers of calcschists and marbles, and boudins of mafic and ultramafic rocks. These latter preserve the record of Alpine (ultra)high-pressure conditions and have been the object of numerous studies in the past years.

The presence of such diverse lithologies lead previous authors to suggest that the Cima Lunga is a subduction channel tectonic mélange. However, recent field studies redefined its internal structure and relationships with the nappes tectonically above and below. The Cima Lunga unit is sandwiched within the upper levels of the Simano and below the Maggia nappes. The deformation within the unit is intense, especially around the mafic and ultramafic bodies enclosed within the paragneisses, and can be explained by shearing affecting the whole unit. In the field, layers of orthogneisses, calcschists, and marbles extend over kilometers, suggesting that these lithotypes cannot be fragments derived from the adjacent Simano.

In this contribution we present a comprehensive map of the Cima Lunga unit. This map is the result of extensive fieldwork performed for the realization of the new Swiss National Maps 1:25.000 (fieldwork at scale 1:10.000) and of the new Tectonic Map of Switzerland 1:500.000. We present within the map a compilation of literature results comprising calculation of pressure and temperature conditions as well as age data. We highlight the spatial distribution of these data, which is fundamental for the comprehension of such an intensely deformed unit.

Our understanding of the evolution of the earliest amniotes during the time span 320 to 270 million years ago on the Pangaea supercontinent is known from only very rare fossil localities, most of which are in North America. The fossil locality Bromacker (Bromacker Quarry) in the Lower Permian Tambach Formation near Tambach-Dietharz, central Germany, has developed after discovering of first bone 1974 until 2010 to be the most important and productive fossil locality for Lower Permian, terrestrially adapted tetrapods outside USA.

Scientific results emerged in 20 years of international collaboration between Dr. Thomas Martens (MNG, Gotha); Dr. David Berman und Amy Henrici (Pittsburgh, USA); Prof. Stuart Sumida (San Bernardino, USA); Prof. Jozef Klembara (Bratislava, Slovakia); Dr. David Eberth (Royal Tyrrell Museum, Drumheller, Kanada) and Prof. Robert Reisz (University of Toronto, Kanada).

We discovered first examples of Seymouridae (Seymouria sanjuanensis), Diadectidae (Diadectes absitus and Orobates pabsti), Protorothyrididae (Thuringothyris mahlendorffae), Bolosauridae (Eudibamus cursoris), Sphenacodontidae (Dimetrodon teutonis) and Varanopidae (Tambacarnifex unguifalcatus) in the Lower Permian of Europe or outside of USA and some new species/genera of Mikrosauria (Tambaroter corrolli), Trematopidae (Tambachia trogallas and Rotaryus gothae), Amphibamidae (Georgenthalia clavinasica) and Caseidae (Martensius bromackerensis).

The Bromacker produces the best preserved terrestrial vertebrate fossils from the Lower Permian time period (about 290 million years ago). Significantly, the locality provides the example of strictly terrestrial amniote ecosystem. Thus, the herbivores and carnivores coexisted in a natural community as early as the Lower Permian.

In an age shaped by digital media and rapid information exchange, science communication is adapting to new tools and audiences. The BROMACKER—a multidisciplinary research project focused on a 290-million-year-old fossil site in Thuringia, Germany—is using social media to make its research more visible and accessible. Through the Instagram channel @bromacker_chroniken, the team shares fieldwork, fossil discoveries, as well as paleontological and geological insights in formats tailored to a broad, non-specialist audience.

This contribution explores how visual storytelling, authentic glimpses into fieldwork, and easy-to-understand explanations can help open up scientific research beyond academic circles. Using concrete examples, it illustrates how humor, visuals, and accessible language turn complex science into something people can relate to and respond to. At the same time, it also reflects on the opportunities and limitations of using social media to communicate evolving research via social media.

By embedding outreach into the scientific routine, @bromacker_chroniken demonstrates how digital media can enrich science communication, spark curiosity, and strengthen the relevance of research in society today.

The present study describes former and new findings of invertebrates from the Tambach Sandstone Member (Tambach Formation, Rotliegend Group; early Permian) at the Bromacker early tetrapod fossil site near the town Tambach-Dietharz (Thuringian Forest Basin, Free State of Thuringia, central Germany). The Lower Permian of Central Europe is mainly represented by continental sediments, deposited close to the Central Pangaean Mountains on the supercontinent Pangaea. Sand- and siltstones of several fossil sites in the Tambach Formation contain a characteristic fauna and flora, indicating extreme environments caused by a continental near-equatorial climate. During our project “Bromacker”, which runs from 2020 – 2025, we excavated fossils of invertebrates accompanied by vertebrates, plants and ichnofossils within the context of our annual field campaigns at the Bromacker site. The low diverse fauna of invertebrates belongs to the groups of conchostracans, insects, diplopods and Hydromedusae, each containing only 2-4 species, which all need revised descriptions. All these invertebrate fossils are preserved as imprints, no body fossils have been found so far. Most common are conchostracans, whereas insects and diplopods are much rarer. Hydromedusae are less frequent and occur within the Tambach sandstone layers but not within the siltstones of the Bromacker horizon. The invertebrates, dominated by arthropods, are representatives of a typical terrestrial fauna which indicates full continental environments in a strongly seasonal climate causing fluctuating wet and dry conditions with non-permanent ponds and floddings.

Research boreholes Fb Altenbergen 01/2022 and Fb Tambach-Dietharz 01/2023 from the perimontane Tambach Basin (Artinskian; 290.1–279.3 Ma) flank the Bromacker excavation site with 2.6 and 1.5 km distance and recovered 250 and 200 m, respectively, of excellent core in fluvial (channel, overbank, floodplain) and conglomeratic alluvial facies. High-resolution analysis of climate-relevant proxies was based on color (CIEL*a*b color space), volume-specific magnetic susceptibility, and carbonate content (of Fb Altenbergen, 92.33 – 198.59 m; 33 cm spacing), supported by gamma-ray logs. Lithologies and measurements readily correlate with each other over the 4 km distance, with the Bromacker site approximately midway. A time-series analysis (spectral analysis, Fourier analysis; multi-taper method) based on the proxy measurement series (with and without conglomerate) shows numerous cycles. The dynamic-chaotic fluvial environment and the climate-independent weathering of the lithic, Fe-rich minerals of proximal volcanic provenance primarily affect high-frequency "short" cycles. Low-frequency “long” cycles, in contrast, consistently show a high statistical significance. We interpret them to represent periodic climatic changes with stronger bioturbation and soil formation, correlated to warmer periods of higher precipitation. Using the frequency-ratio method, cycles compare well to Early Permian orbital (Milankovic) cycles of known astrochronological periods, best to the long eccentricity cycle of 405 ka in the Permian. Fb Altenbergen 01/2022 thus appears to represent a stratigraphic record of ca. 2.13 Ma, Fb Tambach-Dietharz of ca. 2.16 Ma, and a mean sedimentation rate of ca. 12 and 10 cm / ka, respectively, for both compacted and decompacted profiles.

New skeletal material from the early Permian Bromacker locality (Thuringia, Germany) adds critical information to our understanding of early synapsid diversity and anatomy. The first fossil bone ever discovered at Bromacker in 1974—specimen MNG 7744—was never formally described and only anecdotally identified as a potential diadectid skull element (pterygoid). To commemorate the 50th anniversary of this discovery, we reanalysed the partly embedded specimen using micro-CT imaging. The new data reveal that it is not cranial but postcranial in origin: the first known pelvis of Dimetrodon teutonis. During the 2020-2025 excavations, additional, yet undescribed skeletal material that can be referred to D. teutonis was discovered and includes a sacral vertebra, a second pelvis, as well as the first complete femora and ulna assignable to this species. The sacral vertebra also lacks the fusion known from Dimetrodon limbatus and giganhomogenes. We also report new material of the varanopid Tambacarnifex unguifalcatus, the apex predator of the Bromacker ecosystem. Although the postcranial skeleton of Tambacarnifex was previously known, a newly recovered femur is the first complete example. A humerus with incompletely ossified epiphyses, and a size less than 70% of the holotype, it represents the first juvenile varanopid from Bromacker. These finds provide new anatomical data for two key synapsid taxa and refine our understanding of the Bromacker predator guilds. They also demonstrate the value of modern imaging technologies for revisiting legacy specimens and reaffirm the Bromacker locality as a rich source of insight into early terrestrial vertebrate evolution.

A new fossil chimaeroid egg capsule of the ichnogenus Vaillantoonia (previously designated as Chimaerotheca), V. jonasoni, is described from marine lower Carmanah Group strata at Botanical Beach, along the West Coast of Vancouver Island, British Columbia, Canada. According to foraminifera biostratigraphy and strontium isotope dating it is late Eocene (latest Priabonian) in age. The three dimensionally preserved fossil is about 220 mm long and 80 mm wide. The elongated capsule shows a spindle-shaped central body with a constriction at the anterior end that tapers into a spatula-shaped beak. At the posterior end is a long and slender tail that broadens basally. The wing-like lateral membrane has numerous pronounced and narrow ribs (costae) that split in a V-shape.

The producer fish of V. jonasoni is unknown, since no associated skeletal or dental remains have been found. However, the elongated capsule shape and the number and shape of the membrane ribs are most similar to egg capsules of extant longnose chimaeras (Rhinochimaeridae) suggesting a rhinochimaerid-like fish with a “long” nose, in comparison to other modern chimaeroid capsules and their beak shapes.

Following earlier discoveries of V. alaskana (middle Oligocene, Alaska), V. sp. (Oligocene, Washington), and V. sp. (late Eocene, Oregon), which all show rhinochimaerid egg capsule features, this is the fourth Paleogene chimaeroid egg capsule discovered from the Pacific Northwest. All four fossils have in common that they were fossilized in tectonic foreland basins in bathyal water depths, which perfectly correlate with the known bathyal habitats and nesting sites of extant rhinochimaerids.

Recently, a trace fossil of unusual morphology was found in the Cabarz quarry in the Thuringian Forest near Bad Tabarz (Thuringia, central Germany). The specimen was collected at the base of Floor 2B of the quarry exposing rocks of the Lower Goldlauter Formation (Lower Rotliegend, early Permian). The trace fossil is preserved as epi-/hyporeliefs on two siltstone slabs representing part and counterpart. The siltstone surface is of greyish-red colour and shows rain drop marks. The deposit is interpreted as floodplain facies. The trace fossil is discussed to be composed of a central crawling track of the invertebrate body and, along with it, impressions of walking legs on both sides. In the concave epirelief, the crawling track exhibits a string-of-pearls-like structure. Compared to literature, morphological similar impressions of walking legs and the pearl-like central track were known from Diplichnites and Imponoglyphus, respectively. Both ichnogenera have been reported from the study area before. Combining these characteristics in a single trace corresponds morphologically to Glaciichnium, which is currently interpreted to represent locomotion traces of isopods or caddisfly larvae. Glaciichnium-like traces are hitherto unknown from the Thuringian Rotliegend. The inferred locomotion, combining pulsating crawling (Imponoglyphus) and walking (Diplichnites), suggests a behaviour that has not yet been described from any other invertebrate trace fossil from the Thuringian Rotliegend and therefore seems to be rare in the study area.

In this study we compare footprints and trackways of small reptiles assigned to the ichnotaxon Procolophonichnium from two central German study areas: (1) the middle to late Permian Mammendorf quarry close to Magdeburg and (2) the late Permian Kupferschiefer mining area of the Sangerhausen Depression, Saxony-Anhalt. This material is compared to finds from the late Permian Cornberg Sandstone, Hesse and the Early Triassic tracksite of Britten, Saarland. Furthermore, the uppermost Rotliegend to basal Zechstein deposits exposed near Morungen close to Sangerhausen were studied in detail to clarify the depositional environment of the associated footprint finds. In terms of imprint proportions, morphology and size, the Procolophonichnium from the Sangerhausen area is similar to the Mammendorf Procolophonichnium specimens but different from the Cornberg and Britten samples. The trackway patterns of most Mammendorf specimens differ notably from the rest of the sample in their high (normalized) pace length and gauge width, implying a track producer with a different walking style. According to our documentation of the inactive quarry Morungen, the abundant Procolophonichnium finds from nearby spoil tips come from fluvial units that overlie the marine Zechstein conglomerate and underlie a sandy black shale, which is interpreted as the deep-water equivalent of the third cycle of the Kupferschiefer in the typical Zechstein basin facies. Consequently, the track-bearing sandstones are terrestrial equivalents of the lower part of the marine Kupferschiefer. The occurrence of footprints made by non-marine reptiles is probably related to the temporary persistence of an island in the rapidly flooded Zechstein Sea.

Within the past decade, Micro-CT-Scanning and 3D-Rendering have become established methods in palaeontology for both actualistic and fossil studies. While this non-destructive procedure has yielded impressive, species-identifying traits for many fossil and recent organisms, we asked whether it could also accurately reconstruct the delicate skeletons of one of Earth’s smallest vertebrates: dwarf gobies. The material presented here includes the three species of Corcyrogobius Miller, 1972, rare cryptobenthic dwarf gobies of the Adriatic Sea and West African coasts. The specimens, ranging in size between 12 and 25 mm, come from the collection of the British Museum of Natural History, London (BMNH), and the Zoological State Collection, Munich (ZSM). They were micro-CT-scanned, visualized using Amira 3D-rendering and compared with x-ray images and isolated otoliths (hearing stones). Despite common artifacts and dislocations due to scanning errors, the scans revealed a surprising amount of intricate detail. The taxonomically important otoliths could be rendered with high resolution. Even closely overlapping bones, such as gill covers (opercle, subopercle), could be separated using Amira’s segmentation tool. Moreover, previously unknown differences between the three species were detected in the jaw bones, pelvis and vertebral column. A frequently encountered downside was the sometimes poor resolution of the scans and, as a result, of the segmented bones. Additionally, the program had difficulties distinguishing weakly ossified bones from soft tissue.

At this small scale, Micro-CT-scanning presents challenges and may produce misleading results. Nevertheless, our work with Corcyrogobius demonstrates that even miniature vertebrates can be successfully analyzed using this technique.

Marine hydrogenetic iron and manganese deposits have been shown to be excellent geochemical archives of seawater chemistry. The behavior of Sb in marine environments and their interactions with marine ferromanganese (oxy)hydroxides, however, are still poorly constrained.

In this study, we report trace element concentrations and the Sb isotope composition in marine Cenozoic hydrogenetic ferromanganese crusts from the southern Central Pacific.

Antimony concentrations are enriched by a factor of approx. 3.4 × 10⁵ compared to ambient seawater concentrations and is mostly of authigenic nature with minimal detrital input. Antimony behaves similarly to particle-reactive Zr (R² = 0.5) and Hf (R² = 0.6) in the hydrogenetic ferromanganese crusts, indicating Sb enrichment by surface precipitation onto ferromanganese colloid particles without significant desorption. The Sb isotope fractionation factor varies between 0.00 and 0.36‰ for the fractionation between Sb in hydrogenetic ferromanganese crusts and Pacific seawater [1]. The range in Sb isotope compositions (δ¹²³Sb = 0.37 - 0.73‰) in the hydrogenetic crusts may be explained by shifts towards heavier values with higher growth rates or different Sb isotope compositions of seawater during the growth of the crusts. Isotopic Sb fractionation in hydrogenetic ferromanganese crusts may be caused by an interplay of factors (e.g. redox transformation, Rayleigh distillation, and biologically controlled mechanisms).

The results of this study build toward a more comprehensive picture of the Sb isotope system in marine system and highlight the potential of Sb as a deep-time tracer of marine redox conditions.

[1] Rouxel et al. (2003) Chem Geol. 200, 25 - 40

The modern Baltic Sea (BS) surface water is characterized by an excess in dissolved calcium (Ca) of still unknown origin. Our hydrogeochemical study uses the stable isotopes of Ca and carbon to identify potential calcium sources. The composition of dissolved Ca was analyzed in bottom waters of the deep BS basins, in potential freshwater sources, like rivers and creeks draining the southern coastline, as well as submarine groundwater discharge. The role of sediments was followed in a porewater gradient from the Gotland deep basin in the central BS. The results are traced compared to the North Sea and selected tributaries.

Values of Ca isotope in the bottom waters of the BS deeps shift towards more negative values with decreasing salinity and increasing Ca excess. In the porewater, a downward increase in Ca concentrations and decrease in Ca isotope values is associated with weathering of carbonates and/or Ca desorption from clays. The isotope composition of dissolved Ca in the Warnow river draining into the southern BS was within the range of other European rivers, lower than seawater, but more positive than that of rivers draining into the North Sea. Weathering of carbonates by groundwater was found to be a further Ca source depleted in ⁴⁴Ca. Seasonal variations in the Warnow River, with most positive values during summer, are likely due to internal processes that cause Ca carbonate formation in the water column. Concluding, dissolved Ca in the fresh part of salinity gradients originates from carbonate weathering.

Support: DFG, BMBF, DAAD, IOW

Alkaline-earth metal carbonates like magnesite (MgCO₃), dolomite (MgCa(CO₃)₂), and calcite (CaCO₃) are typically formed via atmospheric CO₂ carbonatization. For the synthesis of many carbonates, high pressures or temperatures are required. Unlike these methods, the mechanochemical synthesis of carbonates utilizes ball milling to apply mechanical energy, inducing structural and physicochemical changes and enabling chemical reactions through shear forces, abrasion, impact, and extrusion.[1]

This study investigates the mechanochemical synthesis of K₂Ca(CO₃)₂ polymorphs, specifically fairchildite and buetschliite, synthesized from CaCO₃ and K₂CO₃ in a shaker mill (Retsch MM400). The synthesis and phase transformation pathways were explored using both ex situ laboratory analysis and in situ X-ray powder diffraction, providing insights into reaction pathways and crystallographic transformations. The primary objective of this systematic investigation is to examine how variables such as milling frequency and water/hydroxyl content influence the transformation pathway between the structurally disordered high-temperature polymorph fairchildite and the thermodynamically stable polymorph buetschliite.[2]

This mechanochemical approach also opens pathways for synthesizing other carbonate systems, such as eitelite (Na₂Mg(CO₃)₂), dolomite (MgCa(CO₃)₂), and nyerereite (Na₂Ca(CO₃)₂). Similar studies can be conducted to investigate how variables like temperature, moisture, reactant ratios, and milling conditions influence their polymorphic transformations, providing broader insights into phase control across diverse carbonate systems.

References

1. Weidenthaler, C. In Situ Analytical Methods for the Characterization of Mechanochemical Reactions. Crystals 2022, 12, 345.
2. Kahlenberg, V., et al. Mechanochemical synthesis and transformation of the polymorphic double carbonates fairchildite and buetschliite, (K₂Ca(CO₃)₂): an in situ X-ray powder diffraction study. RSC Mechanochemistry, 2025, 2, 152.

Six Ca-Mg-Fe carbonate reference materials (RMs) were characterized for oxygen and carbon isotope ratios analyses by Secondary Ion Mass Spectrometry (SIMS). This new suite includes four dolomites with Fe# ranging from 0.0004 to 0.3429, one magnesite with Fe# = 0.0099 and one siderite with Fe# = 0.6152. The six samples were split into between 128 to 2048 metrologically identical aliquots, each containing roughly 100 mg of material. We performed a detailed characterization on split materials for their major and minor chemical element composition using EPMA and their mineralogical composition using XRD. The oxygen and carbon isotope reference values were also determined in multiple gas-source isotope ratio mass spectrometry laboratories while the homogeneity of the oxygen and carbon isotope ratios at the sub-nanogram test portion mass were assessed using SIMS. The repeatability of our SIMS measurements varied from ± 0.15 to ± 0.31‰ (1s) for δ¹⁸O and from ± 0.29 to ± 0.71‰ (1s) for δ¹³C. Significant compositional SIMS matrix effects were observed across the dolomite-ankerite and magnesite-siderite solid-solution series in the investigated compositional range. This confirms the need of multiple matrix-matched RMs spanning a wide chemical range in order to get accurate SIMS isotope ratios in minerals that form theses solid-solutions.

Carbonates, which are highly-relevant for lithosphere-biosphere-atmosphere interactions, are prone to modification - especially after being affected by high stresses and strains. Modification of carbonates after extreme stress loading during hypervelocity impact from Ries impact breccias is presented in this study. In calcite aggregates, new grains formed on the expense of partly preserved shocked host grains. The shocked host grains contain e-, f- and r- twins as well as a-type lamellae and have a high Grain Orientation Spread (GOS) of up to 8° (GOS is the mean misorientation angle between all pixels of one grain and the mean orientation of the grain). The new grains, in contrast, do not contain twins and the GOS is generally <1°. Their crystallographic orientation is close to that of the various twins or the host grain. We propose that the new grains have formed from the back-transformation of a transient high-pressure phase formed upon shock. The calcite aggregates show a zonation with variations in MnO- and MgO-contents (0-1.6 and 0-0.4, respectively), which is preserved in the new grains (i.e., the zonation is cross-cut by grain boundaries). This indicates that diffusional processes were relatively minor, which is consistent with fast transformation processes. Heating experiments of shocked carbonates indicates that temperatures after shock were <400°C, as at these temperatures the twinned microstructure is markedly modified. The study of modification processes of highly strained carbonate in impact breccias yields valuable insights into fast transformations in the carbonate system.

We present a newly developed flow and transport simulator for karst systems, designed to model complex flow dynamics and tracer transport in large-scale networks. Based on the Saint-Venant equations, the simulator integrates advanced hydraulic modeling and particle tracking to investigate how conduit geometry and network structure influence flow and transport behavior. It supports both steady-state and transient conditions, under free-surface and pressurized flow. Turbulence is modeled via the Darcy-Weisbach equation with classical friction formulations, and validation includes analytical solutions and the extensive Ox Bel Ha cave system.

Using 3D lidar-derived geometries, we build high-resolution network models to study how geometric simplification, through resolution reduction, affects flooding signals. Downscaling reduces the number of conduits and averages properties such as diameter and roughness, which can mute or eliminate bottlenecks that control flow and hydraulic gradients. This leads to a more homogenized flow regime, altering the timing, magnitude, and spatial distribution of flooding.

These findings have direct climate relevance. As extreme rainfall events intensify under climate change, understanding karst aquifer responses becomes critical for flood prediction and water resource management. Simplified models may underestimate the role of geometric complexity in buffering or amplifying flood signals. Our work highlights the trade-offs between computational efficiency and predictive accuracy, emphasizing the need for resolution-aware modeling when assessing climate-driven impacts on vulnerable karst systems.

During the serpentinization process of ultramafic rocks, hydrogen is generated. Since ultramafic rocks are often buried deep within the subsurface, it is difficult to study the genesis of hydrogen by serpentinization. The Münchberg Massif in northern Bavaria is a stack of nappes, one of which contains numerous serpentinite bodies. The exposure of these serpentinite bodies at the surface at several locations offers an excellent opportunity to study the serpentinization process of ultramafic rocks.

We present new petrological and chemical data of serpentinites from two locations in the Münchberg Massif: Peterleinstein in the west and Zell in the southeast. The petrological, mineralogical and geochemical composition of the serpentinites at both locations are slightly different. Thin section analyses show different degrees of serpentinization at Peterleinstein and Zell. While rocks at Peterleinstein are almost completely serpentinized, those at Zell still show a certain amount of relic minerals. X-ray diffraction analyses reveal several serpentine minerals in both locations but in different amounts with the dominant serpentine mineral antigorite in Zell and lizardite in Peterleinstein. Major and rare earth elements indicate that the serpentinites at Peterleinstein have a protolith of depleted harzburgitic composition, whereas the serpentinites at Zell have a harzburgitic to dunitic composition. Furthermore, major and trace elements indicate that the protoliths for Peterleinstein come from an abyssal setting and the protoliths for Zell are from a subduction zone setting. Therefore, we suppose that the protoliths for both locations may have been situated at distinct locations within or close to a subduction zone.

Geological storage of hydrogen (H₂) is a promising strategy for large-scale energy storage, crucial for integrating intermittent renewable energy sources. Diffusion is a key mechanism governing the long-term containment security and potential migration of stored H₂ within subsurface formations. This study presents analytical assessment and its validation with experimentally measured values of H₂ diffusion coefficient in porous media under conditions relevant to geological storage, specifically using parameters inspired by the Ketzin pilot site for town-gas and CO₂ storage. We employ an enhanced diffusion model based on the Maxwell-Stefan (MS) formulation, coupled with correlations for fluid and rock properties (Peng-Robinson EOS, Chung viscosity, extended Henry's law, Sharqawy brine density, Meyer-Elshahaby brine viscosity). The model calculates the apparent diffusion coefficient (D_app) considering bulk gas, Knudsen diffusion, dissolved phase, and potential minor sorptive transport, including fracture contributions. D_app(H₂) was calculated for representative Ketzin reservoir (sandstone) and caprock (claystone) conditions under varying gas saturations, yielding values consistent with expected experimental ranges (e.g., 10^-9 to 10^-8 m²/s for wet sandstone, 10^-10 to 10^-9m²/s for wet caprock). Phase diffusion analysis revealed significant composition dependence of Fickian coefficients. Results consistently identified water saturation (S_w), tortuosity (τ), constrictivity (χ), and gas phase accessibility (α) as the most influential parameters controlling D_app(H₂). Monte Carlo simulations, incorporating parameter uncertainty based on plausible Ketzin parameters, indicated a potential variability in D_app(H₂) spanning approximately two orders of magnitude, underscoring the need for accurate site characterization. Spearman rank correlation analysis confirmed the high impact of S_w, τ, χ, and α on D_app(H₂) uncertainty.

Fluid-rock interactions can induce significant chemical changes, resulting in metasomatic rock transformations or formation of metasomatic fronts when mass transfer is substantial. Among the chemical agents driving metasomatism, magnesium (Mg) plays a critical role in mafic/ultramafic rock systems, altering bulk composition and mineralogy. Additionally, the mass difference between ²⁴Mg and ²⁶Mg isotopes enables detectable kinetic fractionation.

This study examines a metasomatic reaction zone in the Voltri Massif (Ligurian Alps, Italy), formed through high-pressure diffusional metasomatism of metagabbro by Mg-rich fluids equilibrated with serpentinite. This zone is an ideal natural analogue for reactive fluid flow between the subducting hydrated mantle and the overlying mafic crust. Evidence for Mg metasomatism includes a continuous MgO gradient, transitioning from serpentinite (~40 wt.%) to metagabbro (~5 wt.%). Isotopic analysis reveals significant fractionation: δ²⁶Mg values range from +0.09‰ in serpentinite to -1.1‰ in the reaction zone, then increasing to -0.1‰ in metagabbro. This trend indicates kinetic isotope fractionation driven by Mg diffusion.

A reactive transport model incorporating viscous rheology is applied to investigate porosity- permeability evolution and estimate process duration. Integrating bulk rock major element and Mg isotope geochemistry with fully coupled Thermo-Hydro-Mechanical-Chemical (THMC) model for reactive transport and phase equilibria, we analyze geochemical and mineralogical transformations across the reaction zone. The model results are validated by fitting field-based geochemical and isotopic data, ensuring consistency with observed MgO gradients and δ²⁶Mg fractionation patterns. Systematic numerical simulations and analyses provide insights into the timescales of Mg metasomatism, shedding light on the dynamics of such metamorphic processes.

To predict and identify governing geological processes and their occurrence in space and time one needs to understand at what spatio-temporal scales they are active. The same goes for the design of experiments or numerical simulations and their up-scaling. If one chooses the wrong time window for an experiment, nothing may happen during that time.

Geological patterns in space and time are dependent on a number of processes that scale differently depending on whether or not they are linear or non-linear and on the involved constants (rate constants, diffusion constants). This is important for example for THMC processes in general, but also for the behavior of faults from the micro to macro scale or melt related processes in the Earth's lithosphere. Often the slowest process is dominating the time scale of pattern evolution, therefore cross-over points in space and time are of special interest, where the dominance of one process over another switches. Such cross-overs are critical points where the behavior of the system changes, especially when two processes are competing during pattern formation.

Here we explore five important processes namely elastic wave propagation, fluid or melt pressure diffusion, temperature diffusion, matter diffusion and reactions. For example, if a reactive fluid enters a fault, in a second the fluid pressure equilibrates on a m-scale, the temperature on a mm-scale and matter on the micro-meter scale. We will discuss examples of scaling relations with implications on how we can utilize such scaling phenomena for process understanding.

The forcing exerted over subsurface reservoir during operations to extract geothermal heat causes changes in, for instance, the subsurface pressure and temperature state, which can lead to induced seismicity. Therefore, an appropriate consideration of the expected measurable response of the reservoir is needed to design reliable monitoring systems. Computer assisted simulations of thermo-hydraulic-mechanical (THM) processes in fractured reservoirs allow to get a prognosis of the reservoir state and its evolution during operations and to consequently get the expected seismic event number and ground motion amplitudes as design monitoring criteria. The caveat is that an optimal strategy requires a large number of simulations to testing possible monitoring configurations, which makes the usage of full order models unfeasible because of the high associated computational cost. To bypass this barrier, we explore the use of physics-based machine learning surrogate models using the non-intrusive reduced basis method, to obtain fast and accurate solutions. We showcase this methodology for the construction of reliable surrogate models for a reservoir in the transition between convection and conduction dominated heat transfer, which is representative for a wide range of common conditions encountered in geological reservoirs. We especially highlight the differences, to entirely data-driven approaches. We finally illustrate the integration process into algorithms for optimal sensor placements, and how application specific-constraints can be considered.

A naturally occurring pozzolanic material from Peru was characterized comprehensively to evaluate its suitability as a supplementary cementitious material. The objective was to determine the mineralogical and chemical composition of the material.
The material was processed into powder samples for X-ray diffraction (XRD) and fused beads for X-ray fluorescence (XRF) analysis.

XRD results revealed the presence of sanidine, plagioclase, and cristobalite, indicative of a volcanic, magmatic origin. Minor variations in peak distributions across measurements confirmed the material’s consistent mineralogy.

XRF analysis showed a chemical composition of approximately 74 wt% SiO₂, 14 wt% Al₂O₃, 4 wt% K₂O, and 4 wt% Na₂O, with trace amounts of CaO, Fe₂O₃, and MgO, and a loss on ignition of 0.1%.

Further investigations, including scanning electron microscopy (SEM), Blaine tests (EN DIN 196-6), Frattini tests (EN DIN 196-7) and isoperibolic calorimetry, are planned to assess precisely the material’s pozzolanic reactivity. Preliminary results suggest promising potential for application in the construction industry.

During lithium extraction from spodumene, leached spodumene concentrate (LSC) is generated as a mineral by-product. Previous studies have indicated its promising pozzolanic potential, suggesting its suitability as a supplementary cementitious material (SCM) [1]. This study investigates the influence of the two leached spodumene (LS) modifications in LSC on the evolution of hydration phases and pozzolanic reactivity in cementitious systems. Two LSC samples with differing proportions of hexagonal leached spodumene (H-LS) and tetragonal leached spodumene (T-LS) were selected and incorporated into blended cement mixtures at 10, 20, and 30 wt.%, hydrated for 28 days. The change of mineral phases with reaction was followed by X-ray diffraction (XRD). Subsequent Rietveld analysis was performed to quantify the phases after different reaction times. Additionally, thermogravimetric analysis coupled with differential scanning calorimetry (TG-DSC) and isothermal calorimetry measurements were conducted to gain further insights into the hydration behavior and reaction kinetics. For comparison, synthetic reference phases (α-, β-, and γ-spodumene as well as H-LS and T-LS) were produced and characterized concerning their pozzolanic activity. The results reveal no significant differences in the hydration behavior of the two LSC samples, indicating that both H-LS and T-LS exhibit comparable pozzolanic reactivity. Overall, the ratio of H-LS to T-LS appears to have only a minor influence on the hydration performance and reactivity.

[1] T. Zhang, B. Ma, H. Tan, X. Liu, P. Chen, Z. Luo, Effect of TIPA on mechanical properties and hydration properties of cement-lithium slag system, Journal of environmental management 276, 111274 (2020); doi: 10.1016/j.jenvman.2020.111274.

An accurate quantification of the crystallographic-preferred orientation of weak minerals is the key step to decipher the rock deformation history. Measuring the crystallographic orientations in a thin section provides detailed 2-D information about the microtexture. An established method for this task is the electron backscattered diffraction technique. However, the high-level polishing required by EBSD analysis can produce a bias especially in the modal percentage of fragile minerals such as mica. An alternative method is Raman spectroscopy, which requires minimal amount of sample preparation and surface polishing. This method relies on the fact that the intensity of Raman bands varies depending on the mutual orientation between the polarization direction of the incident laser and the crystallographic axes. Given the polarizability tensor, it is possible to inversely calculate the crystallographic orientation by collecting the band intensity as a function of laser polarization direction. In order to calculate the polarizability tensor of the A and B mode of muscovite, we measured the Raman band intensity as a function of orientation around 360° for a muscovite sample cut parallel to the c-axis. We found that the 196 cm^-1 and the 263 cm^-1 bands are most suitable for orientation measurements. The polarizability tensor can be fitted, which makes it possible to perform mapping of the crystallographic orientation on a thin-section, such as mica schist deformed under deviatoric stress.

The recent upgrade of ID27 at the ESRF, included a portable Von-Hámos X-ray emission spectrometer for simultaneous x-ray emission spectroscopy (XES) that can be used in parallel to x-ray diffraction (XRD) experiments in diamond anvil cells (DAC), with and without laser-heating of the sample. This combined setup, built within the framework of the BMBF-funded ‘NanoExtrem-2’ project, will facilitate in-depth studies of structural and electronic properties under extreme conditions.

To test the XES-XRD setup, DAC experiments were conducted on a magnesiosiderite [(Mg_0.43Fe_0.55Mn_0.2)CO₃] up to 50 GPa. Si(111) and Si(110) analyser crystals were successfully used for measurements of the Kβ_1,3 emission spectrum. The experiments demonstrated that Kβ_1,3 can be acquired within 90 min at photon flux of 10¹² photons/s, using a 23.5 keV beam. At this energy XRD patterns with a maximum scattering vector Q = 6 Å^-1 could be collected within 30 sec. Reducing the energy to 15.6 keV enabled acquisition of Kβ_1,3 in just 30 min at the same photon flux, resulting in a threefold improvement in XES intensity. At this energy, XRD patterns with a maximum scattering vector of Q=3.3 Å^-1 could be collected in 30 seconds.

These results highlighted the potential of ID27 for advanced studies of materials under extreme conditions, paving the way for novel insights into the relation between electronic state and bulk structure of many sample systems that have emission lines at energies ≥ 7 keV.

Acknowledgements

We acknowledge the German BMBF for financial support: BMBF Verbundprojekt ‘NanoExtrem’ 05K19IP2 and ‘NanoExtrem2’ 05K22IP2.

Amphibole is an important fractionating phase during calc-alkaline differentiation in arc magmas. Through the presence of both ferric (Fe³⁺) and ferrous (Fe²⁺) iron in its crystal structure, amphibole has the potential to provide constraints on variations in Fe³⁺/Fe^T ratios and thus magmatic oxygen fugacity (f_O2) of the melt from which it crystallized.

We present major element compositions (electron microprobe), hydrogen isotopes and H₂O contents (secondary ion mass spectrometry), and Fe³⁺/Fe^T ratios (single-crystal synchrotron Mössbauer spectroscopy; SMS) of volcanic amphiboles, which crystallized from magmas recording a wide range of f_O2 (ΔNNO = -1.0 to + 3.0, log units relative to the Ni-NiO buffer). These high spatial-resolution analytical techniques are applied to the same area on each grain thus allowing to correlate data sets and avoid averaging inclusions and intra-grain compositional heterogeneity present in many natural amphiboles.

Amphibole Fe³⁺/Fe^T ratios increase with increasing f_O2 varying from 0.14 to 0.67 over the investigated f_O2 range thus amphiboles may be useful monitors of magmatic oxygen fugacity. However, individual volcanic amphiboles can experience extreme dehydrogenation and associated sub-solidus Fe oxidation (e.g., with Fe³⁺/Fe^T ratios of up to 0.86, low H₂O: 0.17±0.01 wt. % and extreme δD: 421±4 ‰ relative to SMOW), which likely occurred during shallow crustal storage. It is therefore important to combine the aforementioned high-spatial resolution and high-precision analytical techniques to distinguish primary magmatic from secondary amphibole Fe³⁺/Fe^T ratios to interpret Fe³⁺/Fe^T ratios correctly in the context of magmatic f_O2 .

Raman spectroscopy is a vital tool for analyzing the mineralogical and chemical composition of lunar rocks, providing rapid, non-destructive identification of minerals, volatiles, and potential biomarkers. Despite its importance, lunar research is hindered by the absence of a centralized, standardized Raman spectral database for lunar samples, complicating both Earth-based studies and future in-situ lunar exploration. This proposal advocates for the creation of a comprehensive Raman spectroscopy database specifically tailored to lunar geology. The envisioned database would compile spectral signatures from recent lunar meteorite analyses, analog materials, and minerals, enriched with detailed metadata such as instrument parameters, environmental conditions, and mineralogical context. Standardizing data across different instruments would enable robust cross-calibration, enhancing the accuracy of portable Raman spectrometers used by astronauts during lunar missions. This resource would support real-time decision-making, such as identifying valuable samples or detecting hydration features without needing Earth-based confirmation. A key innovation is the database’s optimization for machine learning applications, allowing handheld devices to compensate for lower resolution and field limitations by leveraging high-quality spectral libraries. Adaptive algorithms could further refine analyses by accounting for lunar-specific conditions, such as regolith interference or low gravity effects. For space agencies, the database would streamline mission planning, inform instrument design, and foster global collaboration through open-access data sharing. Additionally, it would benefit terrestrial research and education, uniting expertise in planetary science, spectroscopy, and data science to transform lunar exploration and deliver faster, more reliable geological insights.

Lechuguilla Cave, located near Carlsbad in New Mexico, USA, displays an extraordinary spectrum of speleothems formed by unusually diverse secondary cave minerals, among them various carbonates, sulfates, oxides, silicates, and halides.

Various samples of mineral assemblages taken in the context of a study on unusual speleothems formed by either barite and/or celestine were analyzed using powder XRD-based Rietveld analyses (BRASS software [1]). The samples were crushed and ground thoroughly and filled into flat sample holders. However, when celestine, barite and/or calcite constituted the dominant part of the samples, we encountered strong textures and often more than one preferred crystallographic orientation.

Some samples were re-ground several times, but no significant improvement was achieved, and sample deterioration commenced, as indicated by additional broadening of reflections. Accordingly, the samples had to be analyzed after normal grinding.

The issues could be resolved by using several instances of the same phase, which had most parameters in common except for scale factors, preferred orientations and, sometimes, peak broadening parameters. This approach had additional merits compared to multi-texture models with a single phase, since the relative amounts of the orientational variants could be determined.

This procedure also resulted in better matches of patterns and the retrieval of additional significant information, such as the co-occurrence of two different dolomites and Mg-calcite with various magnesium concentrations. In one case, two different Mg-calcites were present, which could only be identified by peak shoulders.

[1] J. Birkenstock, T. Messner & R.X. Fischer (2025). BRASS 2.4, Universität Bremen, Germany, www.brass.uni-bremen.de

For geochemical proficiency testing well established schemes are existing. One of which is organized by the International Association of Geoanalysts (IAG), named GeoPT. Recently, the need for a proficiency testing that includes the mineralogical composition has been formulated, as the mineral composition does indeed have an impact on the geochemical methods to be used and their respective results. We therefore proposed a simultaneous testing: GeoPT and MinPT. MinPT is to be developed for both classical analysis of the phase composition using bulk methods (e.g. quantitative XRD) and for methods of the so-called "automated mineralogy" (AM) approach using SEM- or µ-XRF-based techniques. We identified and collected five different rock types suitable for a first round of combined GeoPT and MinPT testing scheme, one of which was characterised by a number of analytical techniques in order to define suitable parameters (particle sizes, sufficient complexity, homogeneity of the minerals etc.) for the later material to be used in the combined proficiency testing. The results will be presented. We identified a quite narrow grain size (38–150µm) to which the rock material was ground and sieved, being aware that the material is by no means representative of the initial rock. Nevertheless, the material is now suitable for further processing towards a combined testing scheme. In later steps more complex materials including ores can be developed for these combined proficiency testing.

We present an in-house built micro-focus X-ray setup for diffraction and fluorescence measurements. The complete system was assembled, commissioned and tested in the course of laboratory internships and bachelor education, providing first-hand experience to students in the design, construction of an experimental analytical device and its application to a scientific problem.

At the heart of the machine is a Ag micro-focus X-ray tube with a multi-layer optic that provides a focal spot of 50 µm at a distance of 200 mm with a photon flux of 10⁶ photons/sec at 22 keV. XRD patterns are collected on a mar345 image plate detector. XRF spectra are recorded by a Ketek Si-drift detector with 30 mm² active area and a digital signal processing unit. Beam intensity is monitored by a Si-PIN diode. The sample is mounted on a Huber XYZ stage with one vertical rotation and a second long translational stage perpendicular to the beam. An optical microscope allows for observation of the sample. The whole system is operated using TANGO (www.tango-controls.org) and SARDANA (www.sardana-controls.org).

The performance is presented with three examples: i) quantitative measurements of reference material ii) destruction-free analysis of an unprepared grain of Mukundpura CM2-Chondrit providing spatially resolved semi-quantitative mineralogical and chemical information; iii) in-situ high-pressure measurements of the unit-cell volume of a spinel by XRD up to 15 GPa using a diamond anvil cell.

Acknowledgements: Thanks to: L. Hecht MfN Berlin, E. Bonato, DLR Berlin, for providing the meteorite sample; S. Niese, AXO Dresden, for technical support.

Understanding microplastic dynamics in fluvial systems is key for identifying pollution source and potential long-term sink remediation. While many studies rely on controlled experiments (e.g., columns, flumes, tanks), to understand the behavior of this pervasive anthropogenic particle, in-situ investigations remain limited. This research investigates the deposition and transport behavior of microplastics in relation to natural sediments within a small (ca. 7 km) highly anthropogenised stream near Vienna, Austria, serving as a natural field laboratory.

In April 2025, 18 sediment and 7 water samples were collected from diverse geomorphic sinks—such as bars, backwaters, and areas affected by infrastructure. Water sampling was performed using a 150 µm plankton net (30 cm diameter) to capture surface and suspended fractions. A follow-up sampling campaign is planned after a major rainfall event to evaluate sediment reactivation and the potential remobilization of microplastics from these sinks.

Hydrodynamic parameters were measured, and approximately 60 large wood (LW) deposits were mapped and characterized to assess their role in altering flow patterns and sediment connectivity. Microplastics particle shape, size and estimated density will be compared to natural sediments through grain size distribution and total organic content.

Extraction and identification methods include sieving, density separation (1.45 g/cm³), Fenton oxidation, and non-FPA FTIR mapping for polymer identification.

This research explores to what extent microplastics behave analogously to natural sediments in riverine depositional environments. The findings aim to improve our understanding of microplastic behavior in real-world geomorphic contexts and contribute to broader discussions on sediment dynamics in human-impacted river systems.

Constraining heat transport across the core-mantle boundary (CMB) is key to understanding Earth’s thermal evolution and the operation of the geodynamo. This work focuses on the lattice thermal conductivity of the three dominant minerals in the lower mantle—periclase, bridgmanite, and post-bridgmanite—under relevant pressure-temperature-composition conditions. We apply three complementary atomistic simulation methods: the Boltzmann Transport Equation (BTE), Green-Kubo Molecular Dynamics (GKMD), and Non-Equilibrium Molecular Dynamics (NEMD), to study thermal transport up to 150 GPa and 4000 K. The methodology allows cross-validation and provides insights into the role of anharmonicity and length/time scale effects at deep Earth conditions.

Preliminary results for periclase show consistent trends across all three methods and align well with existing data, including the impact of isotopic substitution. For post-bridgmanite, thermal conductivity has been evaluated using both BTE and GKMD over a range of pressures and temperatures, offering initial insight into its anisotropic transport behavior and confirming method consistency. This work lays the foundation for further studies on how compositional variations—such as Fe/Al substitution and spin-state transitions—affect thermal conductivity in deep mantle minerals.

The origin of raw materials is a key focus in jade archaeology, offering valuable insights into the interactions and exchanges between ancient cultures. Among various jade materials, tremolite nephrite, with its distinctive mineralogical characteristics, was widely used across multiple jade-using cultures in prehistory. Studying the sources of minerals allows for a deeper understanding of the organizational structures and social dynamics of ancient societies. In China, jade artifacts were symbols of status, power, and virtue, with numerous remarkable discoveries from the Hongshan, Dawenkou, Lingjiatan, Liangzhu, and Daxi cultures underscoring jade’s esteemed position in ancient society. These artifacts played a crucial role in the formation of these early cultures. The Nephrite jade deposits in Hebei Province, China, hold significant archaeological and cultural value, particularly concerning the Neolithic period and the archaeological cultures of China. Nephrite jade was highly prized during the Neolithic era, and its use is evident in various archaeological sites. Geochemical analysis of raw material sources has become an indispensable tool in archaeology, providing a clearer understanding of how ancient cultures sourced and valued jade, facilitating the study of cultural exchanges. The geographical distribution of Hebei nephrite jade, along with its gemmological properties, suggests its central role in understanding the importance of jade within Neolithic Chinese cultures. The use and craftsmanship of this material reflect its cultural, spiritual, and social significance, further emphasizing its integral role in early Chinese history and its potential as a medium for intercultural interaction.

Stable isotope analyses of archaeological finds from coastal environments have been shown to be influenced by sea spray. Sea spray consists of aerosols derived from seawater that may contain various ions, potentially resulting in a marine-like isotope signature in terrestrial organisms. This so-called sea spray effect can hamper or even falsify the reconstruction of the diet or provenance, for example when investigating archaeological human skeletal remains. The magnitude of the sea spray effect and the underlying mechanisms are still unknown. In order to quantify the present-day local sea spray effect on several isotope systems (δ¹³C, δ¹⁸O, δ³⁴S, ⁸⁷Sr/⁸⁶Sr) at different sites close to the North and Baltic Sea, modern environmental samples are investigated. This will help us to understand the effect of sea spray on biochemical pathways in plants and the isotope signature of organisms feeding on them. Preliminary results show seasonal and regional variations in the local sea spray effect in plants. This suggests that a varying sea spray effect should also be expected in prehistoric samples from different archaeological sites. Investigating modern environmental samples of known origin will provide a better understanding of the local sea spray effect and enable the correction of the isotope fingerprints of (local) archaeological remains (e.g., animals, humans) against the regional sea spray effect. This will result in a more correct diet or provenance reconstruction and, thus, a better understanding of the past.

Paleohistology, the study of fossilized bone microstructure, is crucial for understanding the growth and life history of extinct vertebrates. Traditional methods rely on destructive thin-sectioning, limiting its application. Micro-computed tomography (μCT) offers a non-destructive alternative using X-ray, but its reliability for paleohistological analysis remains underexplored. This comparative study evaluates the effectiveness of μCT by analyzing 14 sauropod specimens representing multiple genera, ontogenetic stages, and geological formations, using μCT scanning and thin-section microscopy.

μCT successfully visualized key histological features, including vascularization, secondary osteons, and lines of arrested growth (LAGs), with a strong correspondence to thin-section data (K = 0.71–1.0). Scans of specimens under 15 mm in diameter showed all considered structured with a level of detail comparable to the thin sections. In some cases, μCT revealed features more clearly than microscopy, especially when diagenetic infilling obscured thin sections. While artifacts and noise can often be mitigated, larger specimens require scanning at greater distances, increasing voxel size and thus reducing resolution - a trade-off determined by field-of-view limitations rather than bone size. Advances in technology and reconstruction algorithms continue to improve image quality, highlighting the importance of archiving raw data for future reprocessing.

μCT’s advantages include three-dimensional visualization and the ability to study intra- and interskeletal series non-destructively. This approach preserves fossil integrity and promotes data sharing and reproducibility. Our findings validate μCT as a powerful tool for virtual paleohistology. Future directions include the standardization of protocols and integration with advanced imaging techniques and machine learning to further enhance resolution and accessibility.

The TUNB project, conducted from 2014 to 2021, marks an important step in the geological 3D modelling of the North German Basin. Through the collaboration of the State Geological Surveys of the participating federal states and the Federal Institute for Geosciences and Natural Resources, a comprehensive 3D model was created, comprising 13 geological horizons and important structural elements such as faults and salt structures. The model serves as a basis for a wide range of subsurface applications, from CO₂ storage to the final disposal of radioactive materials.

The ongoing follow-up project, TUNB Velo 2.0, builds on this foundation by developing a parameterized, seismic velocity-based volume model. In this project, each participating Geological Survey contributes its own model component using regionally available data, workflows, and modelling strategies. Depending on data availability and local priorities, this includes, for example, stacking velocities, checkshots, and borehole sonic logs. The aim is to enable a more accurate time-to-depth conversion of seismic data and to support improved geometric interpretations of the subsurface on a regional scale.

Now TUNB Velo 2.0 is progressing towards its final phase. This poster presents an overview of the project’s goals and background, summarizes the current status of model development, and outlines the modelling concepts used to integrate velocity information into a geological framework. Detailed contributions on specific methods, datasets, and regional modelling strategies are presented in accompanying talks and posters, and illustrate how the resulting model components may support further geological investigations in the respective regions.

Reliable velocity models are crucial for accurate seismic time-to-depth conversion. Existing regional velocity models in Saxony-Anhalt date back to the 1970’s, indicating the demand for updated models based on recent data. Current best practices in geophysical modelling call for the development of three-dimensional velocity models to account for the structural complexity of the subsurface.

A modelling workflow has been developed for the northern part of Saxony-Anhalt, building upon the 3D structural model of the North German Basin from the TUNB project. Vertical seismic profiles from more than 200 boreholes form the essential data basis. Initial velocities and depth gradients for 8 velocity intervals from top Cenozoic to base Zechstein were determined. Linear interval velocity-depth functions were derived and calculated within a 3D voxel-based model. Finally, the model is aligned with recently developed ones of the neighboring federal states and compared to vintage velocity models.

Our workflow represents an efficient and modern approach for 3D velocity modelling and can be easily extended to other areas and 3D models. The large-scale velocity model will serve as starting model for future (re-)processing campaigns and supports planning and interpretation of upcoming local seismic studies.

Variogram modelling is a useful method to characterise spatial uncertainty of geological formations. For underground radioactive waste repositories, the spatial definition of the formation containing the repository is critical, as several geometric requirements need to be met to achieve safety standards. We propose to characterise the geometrical uncertainties of the formation containing the repository through the definition of a variogram range, sill and nugget from 2D seismic data. Starting from an initial model of acoustic impedance, we perturb it by adding a Gaussian field to it that is generated by sampling from range, sill and nugget distributions; and compute its corresponding seismic forward simulation to later measure the misfit with respect to the 2D seismic data. By converting the misfit to a probability value that represent the feasibility or likelihood of that realization, and by analysing the time shifts between the same-coordinate seismic traces of the seismic forward simulation and seismic data, we obtain distributions of the variogram parameters that can later be used to characterise the uncertainty in other points of the formation containing the repository, in 3D, where seismic data or other sources of information are not available.

As part of the TUNB Velo 2.0 project, a new seismic model in the time domain was developed for the northeastern part of the North German Basin – as a supplement to the existing depth model of Mecklenburg-Western Pomerania (Obst et al. 2024). The time model is based on interpreted and reinterpreted 2D seismic profiles from the 1960s to 1990s and opens up new possibilities for identifying structural features that were less pronounced at depth due to the inhomogeneity of the velocity field as well as the presence of salt bodies and fault zones with potentially anomalous velocities.

Since existing archive data was mainly used to build both models, primary data that was not available for deep modelling could also be taken into account for time modelling in some areas. The subsequent comparison and mutual conversion between time and depth models based on a harmonized 3D velocity field enabled us to check and to refine the existing depth model.

The time model therefore proved to be not only an intermediate step in the modelling process, but also an independent instrument for validation and regional analysis that significantly improves the reliability of geological reconstructions in the basin. In addition, this methodological approach can also serve as a practical tool for quality assurance of geological models in other regions with heterogeneous data.

Ref.:

Obst, K., Brandes, J., Matting, S., Wojatschke, J. & Deutschmann, A. (2024): Das 3D-Untergrundmodell des Landes Mecklenburg-Vorpommern: Datengrundlagen, Modellierungsergebnisse und Anwendungsmöglichkeiten. – SDGG 100: 59-92. DOI: 10.1127/sdgg/100/2024/59

A comprehensive understanding of reservoir architecture in complex karst environments requires the integration of geological and hydrogeological data within three-dimensional modelling frameworks. This study presents the first 3D geological and hydrostratigraphic model of the Agourai Plateau in Morocco, developed using the Groundwater Modeling System (GMS). The model integrates a diverse set of datasets, including borehole logs, geological maps, geophysical interpretations, structural network analyses, and piezometric measurements.

This integrated modelling approach delineates the spatial extent of geological units and refines the structural framework of the study area, capturing the complexity of the karst system. Notably, the incorporation of piezometric data into the solid model enhanced the traditional geological model, enabling the generation of detailed piezometric surfaces and high-resolution hydraulic cross-sections. The model identifies eight distinct geological units, from the basement rock to the overlying aquifer formations, with the total groundwater storage volume of the karst aquifer estimated at 36.3 × 10⁹ m³.

In addition to mapping the distribution of major faults that control groundwater dynamics, the model provides new insights into subsurface flow patterns and highlights the role of abandoned quarry zones in influencing the aquifer system. This regional-scale model demonstrates the potential of integrated 3D modelling as a decision-support tool for the sustainable management and protection of groundwater resources in vulnerable karst regions

During the TUNB Velo 2.0 project, the State Geological Surveys of Schleswig Holstein, Lower Saxony, Mecklenburg Western Pomerania, Brandenburg and Saxony-Anhalt together with the Federal Institute for Geoscience and Natural Resources (BGR) developed a large-scale seismic velocity model for the North German Basin. The structural model of the previous TUNB project formed the basis for modelling. However, the project partners did not use a consistent classification of geological layers when assigning the interval velocities. Furthermore, different methods were used for creating the volume model and its parametrization. Additionally, input datasets for the velocities varied between project partners. All these differences necessitate the harmonization of the velocities at the borders to have a consistent regional model. The harmonisation methods were tested in a pilot region and differ for each border. Velocities were mainly consistent between Lower Saxony and Schleswig-Holstein because we used the same regional velocity model as a basis. With Mecklenburg Western Pomerania, the theoretical surface velocities and gradients were interpolated to harmonize the interval velocities. For Brandenburg and Saxony-Anhalt, a weighted interpolation of the interval velocities in a buffer zone was applied.

On the poster, we present an overview of the harmonization strategies applied along the borders between Lower Saxony and its neighbours. We highlight different border-specific approaches and illustrate how we achieved regional consistency despite varying methodologies and datasets. Selected results from the pilot region demonstrate the effectiveness of the applied methods and their impact on building a coherent velocity model for the North German Basin.

Intensive lignite mining in the Lausitz region has significantly influenced both the environment and local communities over the past 150 years, shaping a unique cultural landscape. The region now faces a range of complex challenges – geotechnical, hydrogeological, hydrological, and energy-related – that affect not only human settlements but also the natural ecosystem. The Lausitz deposits are characterised by Cenozoic sequences resting on a northward-dipping pre-Tertiary bedrock. Tertiary strata were shaped by repeated marine transgressions interacting with paralic and terrestrial systems. Overlain by Quaternary glacial and interglacial deposits associated with eroding channels and extensive glacial deformation zones.

The study area covers an area of 11,500 km² (7,450 km² Brandenburg and 4,050 km² Saxony) and represents a sediment thickness of up to 350 m. The aim of the Project is to provide a detailed 3D model of the geological situation independent of national borders and associated political responsibilities. It will provide a spatially resolved representation of the Quaternary and Tertiary successions, serving as a fundamental tool for subsequent modelling – such as groundwater flow simulations for transboundary groundwater management in Saxony and Brandenburg.

In the current phase of the project, the focus is on developing the methodological approach, data management, statistical analysis and technical data processing. Integrating data from various sources to create accurate representations of geological formations. More than 178,000 boreholes are currently available for quantification and qualification, supported by layer information including lithological parameters and stratigraphic interpretation. Existing geological model approaches will be updated and optimized for further processing.

Understanding the reactivation potential of geological fault zones in the deep subsurface is crucial for evaluating the feasibility of subsurface uses, such as CO₂ and hydrogen storage, geothermal energy, and radioactive waste disposal. This study investigates the reactivation potential of faults across Germany, using fault-specific datasets (e.g., fault traces, 3D models, or focal mechanism solutions) to demonstrate different application procedures. We considered the parameters of slip tendency (ST) and dilation tendency (DT), where ST quantifies the tendency of fault reactivation by shear under a given stress field, and DT indicates the tendency of a fault to open, thus acting as a fluid migration pathway.

For a first approximation of present-day stress conditions, we used data from a 3D geomechanical numerical model by Ahlers et al. (2022), which covers the onshore and parts of the offshore regions of Germany. From our perspective, ST and DT are robust and computationally efficient parameters that can be reliably derived from fault data in various formats. This study presents the methodology for calculating these parameters and discusses the strengths and limitations of the input data.

The results contribute to a better understanding of fault behaviour under current stress conditions and may support a first approximation of geological suitability for subsurface applications. However, further refinement of the stress model would be essential to achieve more reliable and site-specific results.

The Pricaspian Basin represents an approximately 600 km wide (east-west) structure at the northern edge of the Caspian Sea. Isolated from the Paleo-Tethys by carbonate massives, this structure was filled with up to 4.5 km thick Permian (Kungurian and Roadian (Kazanian)) evaporite rocks and covered mainly by clastic sediments in post-Roadian times. From the late Permian and intensifying in the Triassic, halokinesis led to the rise of salt diapirs, which highly deformed the salt successions. This diapirism continued in a later movement phase between the Jurassic and the Neogene resulting in more than 1.500 salt dome structures known in the Pricaspian Basin. These salt dome structures are of economic interest, e.g. for gas, oil, potash, and borate.

With the help of seismic investigations, as well as lithological and chemical analyses from drilling results, a 3D model of a potash deposit was created. This 3D model represents a case study of a complex tectonic and halokinetic genesis within a salt diapir of the Pricaspian Basin.

As part of the transnational TUNB velo 2.0 initiative, the Geological Surveys of Mecklenburg-Western Pomerania and Brandenburg contribute to the development of a 3D seismic velocity model of the North German Basin. Building on the 3D geological framework established in the predecessor TUNB project, which spans from the Cenozoic to the base of the Zechstein, this new phase involves transforming surface-based models into voxel models parameterized with seismic velocity data.

The seismic velocity data used for model parameterization stem from extensive hydrocarbon exploration campaigns conducted in both federal states between the 1960s and 1990s. Although the primary focus was on deep Permian reservoirs, data were systematically collected for Mesozoic formations as well. The dataset includes a substantial number of check-shot surveys and vertical seismic profiles (VSPs) from over 250 well, regional velocity models, stacking and migration velocities.

In a pilot region in Northwestern Brandenburg (Southwestern Mecklenburg–Western Pomerania) a concept was developed to revitalize the historical data with modern methods and cross-border harmonization was achieved in TUNB velo 2.0 showing promising results for a seamless 3D velocity field.

Groundwater in the Niger Delta remains a critical source of potable water, yet it is increasingly threatened by contamination from petroleum-related activities and other anthropogenic sources. Few studies have comprehensively assessed the presence of contaminants in unconfined Niger Delta aquifers. This study investigates the spatial distribution of lead and benzene in both closed and open wells within the highly permeable floodplain sands of the Benin Formation underlying oil-producing municipalities in Rivers State, Nigeria. Groundwater samples were collected during the dry season in January 2025. Benzene was analysed from closed wells only, and lead was measured in both well types, ensuring representative spatial coverage. Results reveal significant spatial variation of benzene concentration, with the highest detected concentration reaching 26,460 µg/L, near petroleum infrastructure. A total of 16.7% of groundwater samples exceeded the WHO standard limit of 0.01 mg/L for lead in drinking water. More closed wells, which sample deeper into the aquifer, are contaminated with lead (20.6%) compared to shallower open wells (4.5%). Dissolved oxygen (DO), averaged 5.88 mg/L, was lower in samples containing benzene, suggesting natural attenuation processes. Ongoing work seeks to contextualize these findings relative to groundwater recharge estimates using a water balance approach based on climatic data. By translating our conceptual model into a numerical flow and transport model, we aim to shed light on the potential long-term implications of lead contamination in the aquifer. Our results highlight the urgent need for improved management and stricter regulation of petroleum activities to safeguard groundwater resources in the Niger Delta.

Mineral resources and water have been uniquely interwoven in the Harz Mountains region. For centuries, the waters of the Harz powered mine drainage systems and were channeled through an ingenious network of drainage tunnels. Today, the Harz region has great importance for supra-regional drinking water supply. With climate change, extreme hydro-meteorological events are putting increasing pressure on existing water infrastructures. The Ernst-August-Stollen (EAS), a 40 km long drainage tunnel in the Upper Harz, offers potential for underground storage and other water management uses. In the EAGruMo project (Ernst-August-Grubenwassermonitoring) we aim to assess this potential by understanding the hydrogeological system of the EAS, estimating water residence times in the Paleozoic fractured aquifers, and quantifying water flow rates. Methodologically, we employ stable water isotopes, conduct tracer tests, and perform hydrological investigations (field studies, modeling) to gain a deeper process understanding of water dynamics. These hydrogeological investigations are complemented by the continuous monitoring of water quality and quantity, in order to evaluate the suitability of the tunnel system for water management uses, taking into account local geological and hydraulic conditions. The insights will not only benefit the Harz region but can serve as a model for other post-mining regions facing similar water management challenges under changing climatic conditions.

Mexico's Purisima Reservoir is a significant aquatic ecosystem and a designated protected natural area. To comprehensively understand its environmental health, a recent study evaluated the reservoir's water quality and contamination through an integrated scientific approach. This involved analyzing water and sediment samples for metal/metalloid content and physicochemical properties. Data processing utilized WAWQI, PAST 4.03, JMP15.2, and QGIs 3.26.3. Primary elements found in the reservoir's water (0.002–0.1 mgL⁻¹) included
cadmium (Cd), chromium (Cr), mercury (Hg), lead (Pb), and arsenic (As). Strong associations (p<0.05) emerged between several element pairs: Pb and As; Cr with Hg and Pb; Hg with Pb and zinc (Zn); and Cd and Pb. Sediment analysis at 25 reference points concurrently showed arsenic (As) as the contaminant most enriched, largely due to anthropogenic mining and mineralization. Other elements generally mirrored natural crustal rock concentrations. We categorized the Purisima Reservoir's water quality as "poor," but biomonitoring revealed it to be "moderately polluted." This research offers vital insights into the environmental health of the reservoir, providing essential guidelines for preventive and corrective measures to manage and conserve this critical water resource.

Keywords: Heavy metals, Purisima Reservoir, Arsenic, water, sediment, WAWQI.

Thermo-hydro-chemical (THC) reactive transport in fractured geothermal reservoirs plays a critical role in optimising thermal energy extraction and ensuring sustainable management. This work presents an integrated modelling framework that couples geochemical simulations using PHREEQC with thermo-hydraulic calculations in COMSOL Multiphysics via the iCP software program. It focuses on the Middle Buntsandstein sandstone unit in the Wörth am Rhein area, where the Dekapalatin project is currently being implemented.

This study investigates the influence of varying brine and mineralogical compositions on a fractured geothermal reservoir. Therefore, a series of scenarios is designed to explore these effects on the reservoir behaviour. These scenarios investigate spatial and temporal changes in the reservoir characteristics. Explicitly, detailed alterations in porosity and permeability resulting from mineral dissolution and precipitation are evaluated, along with their implications for geothermal flow-path development and thermal breakthrough dynamics in the fracture network.

The results indicate that variations in brine and mineralogical compositions can lead to spatially heterogeneous alterations in fracture apertures. These alterations, in turn, modulate local fluid velocity and heat transfer. Secondary precipitation processes, notably of carbonate minerals, are expected to have a relatively significant influence on reservoir porosity and permeability. On the other hand, dissolution processes may promote the development of additional flow paths within the fracture network.

This study improves our understanding of thermo-hydro-chemical interactions in fractured geothermal reservoirs and provides a clear framework for quantifying uncertainty in reservoir management. The coupled approach improves the reservoir performance predictions and informs sustainable decision-making for geothermal exploitation.

Within the sedimentary succession of Zechstein to Lower Jurassic in the Leinetalgraben, stacked channel sandstones of the Middle Buntsandstein are the most promising geothermal reservoirs for Göttingen. Located in depths of ca. 800-1.400 m, reservoir temperatures are estimated to vary from 35-55°C.

Two seismic sections were interpreted and a 3D-structural model was built in combination with outcrop and scarce well data. Structural analysis confirmed the two-phased tectonic model for graben formation proposed previously, with an early W-E extension and later NW-SE compression. The pinnate eastern boundary faults continue towards the graben centre, resulting in highs and lows within the graben.

Statistical analysis of petrophysical properties of the Middle Buntsandstein was based on core plug data from wells in Lower Saxony. The average sandstone porosity is ca. 9.3% (p10: 1.8%, p90: 21.1%), the average permeability is ca. 7.8 mD (p10: 0.005 mD, p90: 263 mD). The very high range of both parameters most likely reflects not only sample depth but also the abundance of authigenic minerals within the intergranular volume and their degree of dissolution. Due to the complex fault evolution and mudstone interlayers, an enhancement of reservoir properties within fault damage zones cannot be assumed.

Following the wide range of petrophysical data, for a geothermal doublet a flow rate between 1.3 l/s (p90) and 101 l/s (p10) has been calculated, with a mean of 29.5 l/s. However, as typical for geothermal doublets in northern Germany and neighbouring regions, this wide range poses a significant economic risk for a geothermal project.

Aquifer Thermal Energy Storage (ATES) is a promising technology for storing excess energy in urban environments, offering high energy storage capacity with a minimal surface area footprint. Despite its potential to support urban decarbonization efforts, the planning, approval, and implementation of ATES systems in Germany remains limited, partly due to uncertainties regarding long-term performance and environmental impacts within the subsurface. In particular, mineral precipitation and biofilm formation may clog wells and aquifers, thus posing operational challenges.

To assess temperature-dependent biogeochemical processes, sterile and non-sterile water-saturated column and batch experiments are performed at 20°C, 40°C, and 80°C. Natural siliciclastic sediment, derived from an ATES exploration drilling in Berlin, is used in the column experiments, while artificial siliciclastic sediment is applied as analog material in the batch experiments. All experiments are carried out using natural saline groundwater from a potentially ATES-suitable ~200 m deep saline aquifer in Berlin. The column experiments are conducted under an Ar/CO₂ atmosphere and focus on investigating dissolution and precipitation processes, (de-)sorption phenomena, (bio)clogging, microbial activity, and shifts in microbial community composition. The batch experiments examine the change of microbial abundance, activity and community composition, under four distinct gas atmospheres: N₂/CO₂, H₂/CO₂, Ar, and air.

Preliminary microbiological results indicate proliferation and higher microbial activity under anoxic compared to oxic conditions, and at low to moderate temperatures relative to high temperatures. The presence of microorganisms appears to induce changes in iron mineralogy.

The results will support the understanding and mitigation of mechanisms responsible for efficiency loss in ATES systems.

The Upper Rhine Graben (URG), located in southwestern Germany, is well-known for its exceptional geothermal potential. As part of the European Cenozoic Rift System, it is characterized by complex fault-fracture networks that facilitate deep fluid flow leading to zones of pronounced heat anomaly, with geothermal gradients up to 100 °C/km. The geothermal site Wörth am Rhein of URG is an important target for deep geothermal energy production due to its high subsurface temperatures (> 160 °C) in the sedimentary aquifers as Muschelkalk and/or Buntsandstein, which can be used for industrial heating purposes. This type of geothermal play system is catalogued as non-magmatic, convection-dominated, fault-controlled. Recently published work suggests that the URG is characterized by large confined convection cells associated with hydraulically active fault zones.

Therefore, it is of paramount importance to understand, on a regional scale, the main factors and mechanisms that control the distribution of the thermal field in this type of geothermal play. Hence, in order to minimize the associated exploration risks, it is necessary to develop 2D/3D thermal-hydraulic (TH) models on a regional scale that combine existing static and dynamic data with robust numerical modeling following a stepwise complication approach. This integrated procedure provides valuable insights into the geothermal potential of the Wörth area and provides a framework for similar studies in other geothermal regions with similar geological settings. The results of this work contribute to the development of more efficient and sustainable geothermal energy development strategies and support the transition to renewable energy sources.

The Bavarian Geological Survey is developing a comprehensive petrophysical database for characterization of the underground potential. It includes thermal, hydraulic, elasto-mechanical, and electromagnetic rock properties, from samples from our drill core repository, containing more than 90,000 m core/cuttings material.

A standardized internal lab workflow allows for the determination of several parameters in a single sample, including thermal conductivity and diffusivity (under dry and saturated conditions), bulk and grain density, porosity, and magnetic susceptibility. Selected samples are further analyzed for ultrasonic velocities, uniaxial compression, mineralogy (XRD), and geochemistry (XRF).

Currently, the database features over 6,500 samples from 70 drill cores, representing more than 280 geological (sub-)units and 70 lithological types described with different levels of detail and ranging from 0.2 to 5,400 m depth. All data must fulfill five minimum criteria and are georeferenced for 3D geological modeling at different scales. For these models, two distinct data generalization approaches are used: a “Top-to-Bottom” approach for rapid estimation using medians for lithologies and geological units, and a “Bottom-to-Top” weighted averaging, which accounts for the lithological/geological heterogeneity of each model layer.

The database plays a key role in current LfU projects, especially in geothermal reservoir modelling in the Bavarian Molasse basin. Its usage extends to research on CO₂ capture and storage, search for a radioactive waste repository, as well as hydrogen production and storage. Public data access to this database via the “UmweltAtlas Bayern” online platform is under development in accordance with the German law (Geologiedatengesetz, 2020).

Kohlenkalk, a lower-Carboniferous carbonate, is targeted for geothermal exploration in Weisweiler, NRW. In the area, both the NNW-directed Variscan shortening and the Tertiary WSW-ENE Lower Rhine Graben extension significantly affected Kohlenkalk, creating structures on the m- to km-scale that likely control geothermal fluid pathways. To understand these controls, we have classified and characterised structural elements of Kohlenkalk outcrops into fluid conduits (bedding characteristics, joints, fractures, karsts, fold hinge collapse zones) and barriers (clay smears on flexural slip folds and normal/thrust faults). Our data allow the definition of Hydraulic Flow Units (HFU) within the deformed Kohlenkalk sequence in Weisweiler and thus the identification of the most likely geothermal flow pathways.

To assess the sensitivity of these flow pathways to changes in the chemistry of the geothermal fluid, we performed a series of flowthrough experiments on Kohlenkalk sub-members. 4D microCT and post-mortem SEM data, as well as ion chromatography analyses on pore fluids yielded a time-resolved sequence of evolving transport properties, host rock mineralogy, and pore morphology under geothermal conditions.

Our two-pronged investigation combines field- and laboratory data to contribute additional insights on the multi-scale thermo-hydraulic-chemical behaviour of Kohlenkalk in Weisweiler. The dataset is ready to be utilised by digital modelling, which will improve exploration accuracy, reduce risks, and ensure the long-term sustainability of geothermal energy production in carbonates.

The ongoing structural transformation from the hydrocarbon industry to sustainable green energy is one of Europe's current challenges. In Germany, there are about 15,000 boreholes with depths ≥ 400 m (deep wells). Transgeo, a transnational project (EU Interreg program), aims at identifying the potential of such boreholes for geothermal energy production in Germany (+4 other countries). A central aspect of the project is the collection of data from deep wells. This data is then entered into databases and fed into a web-based IT-tool to demonstrate the potential of deep wells for geothermal energy production to future investors. The reuse of old wells, especially former oil or gas wells, is particularly attractive as it can reduce the costs of otherwise very expensive geothermal drilling while utilizing existing infrastructure. The deep wells in the eastern part of the North German Basin are mostly several decades old. As the former GDR was seeking economic independence, considerable effort was put into exploring and mapping national raw material deposits. Therefore, numerous comprehensive studies and data collections are still available in the archives. Analyses of samples taken, measured parameters, etc., are invaluable. The important parameters are not only temperature, porosity, and permeability in identified pay zones within formations of interest, but also technical data on well construction. Once abandoned, detailed information on the location of cement bridges and geological background information or technical problems during or after the drilling process becomes important when considering reuse or planning a new drilling.

Geothermal energy is a crucial part for the energy transition towards renewables and highly in demand by municipal energy providers to supply energy via their district heating networks. The North German Basin in Brandenburg was explored heavily during the 1960-1980s for hydrocarbons. Despite the amount of vintage hydrocarbon exploration data such as seismic surveys or borehole logs, most data can only be accessed at the GeoArchiv at the Landesamt für Bergbau, Geologie und Rohstoffe (Geological Survey Brandenburg). The majority of the vintage data is not yet digitized.

The Geological Survey and the Ministry for Economic Affairs, Labour, Energy and Climate Action agreed on an Action Plan (Aktionsplan Tiefengeothermie) to kick start geothermal exploration in the federal state of Brandenburg. Until 2028 Brandenburg invests heavily in

(I) its IT infrastructure to convey digitized data to stakeholders and consultants but also in providing direct downloads for open data according to the Geology Data Act (Geologiedatengesetz),

(II) digitizing vintages exploration data as well as homogenize and enhance selected data by reprocessing or vectorization,

(III) identifying and closing data gaps by state funded exploration applying geophysical exploration methods and

(IV) providing new open data by a state funding drilling campaign including petrophysical, mechanical and chemical data on selected reservoir horizons within the North German Basin.

The Action Plan will be supported by ongoing public outreach to inform stakeholders or investors within Brandenburg as well as the general public in the areas targeted for exploration.

Global climate change, resource depletion, and land use change require local solutions that acknowledge the configuration and history of its landscapes and the related social-ecological processes. Particularly sensitive to climate change are high-mountain tropical regions. The Andes, where Ecuador’s capital Quito is home to c. 3 million people, host globally-important biodiversity hotspots, organic rich soils and water storage capacity of utmost importance for rural and urban areas.

We would like to present 1) how we co-designed an inter- and transdisciplinary research agenda on land use and landscape dynamics under global and local change that considers local knowledge and landscape evolution, and 2) what challenges we identified to make this research happen. With researchers from Ecuador, Germany, and Poland and members of NGOs and local communities we explored future study areas and the most pressing subtopics in a region of active geodynamics (volcanism, earthquakes) and highly sensitive to climatic extremes that co-drive Earth surface processes (e.g., soil erosion, vegetation fires). We discussed about “landscape” as a potential conceptual framework and about decolonial methodologies on “how to research together”. We furthermore explored lakes as sedimentary archives of past landscape dynamics, as well as current ecosystem functioning using vegetation surveys, state-of-the-art remote sensing and field mapping. Overall, we recognize high potential to co-create actionable knowledge that addresses the interconnectedness between societal and natural systems, and to contribute to tackling ongoing and future land use challenges in the tropical Andes.

Studies of the location, function, and chronology of ancient hydraulic systems are crucial to understanding human adaptation to arid lands. Integrated archaeogeophysics are essential methods to document these buried, little visible and very extended structures. Such systems for water catchment and management (e.g., aflaj) were likely used for irrigation and made it possible to maintain sustainable occupation from the earliest oasis sites until recent times.

Here we report on archaeogeophysical field investigation that was carried out near Bisya, Oman, where two major wadis converge in a plain that had been a fertile oasis at least since the Bronze and Iron ages until the Islamic period. The first implementation, extent and chronology of such water management system is still little known, as well as the functional purpose of different identified round structures, especially in relation to the known decline in water abundancy in various historical periods.

At Al-Dhabi site, a discovery of ditches was made with Geomagnetics and Georadar, later confirmed by excavations. At Fell site, a channel could be identified by Georadar. Geomagnetics revealed the existence of an elongated structure with one circular side, further connected channels and a second area twice encircled by magnetic anomalies. At Salut site, Geomagnetics confirmed the existence of ditches, that surround the elliptical structure, and a strong anomaly indicates the location of the central well. All anomalies are related to the contrast between the formerly water-logged fine sediments in the channels and ditches, the bulding material of deteriorated mud bricks and calcrete rocks.

Obliquely convergent plate margins and continental collision zones, such as the Andes and Tibet, respectively, are often characterized by crustal-scale, rhomb-shaped basins enveloped by transpression zones. The geometries and sizes of such basins, typically evident as low-strain upper-crustal domains, and their transpressive margins are highly variable. Using two-layer analogue experiments, crudely scaled to length and strength of viscous lower and brittle upper continental crust, and horizontally shortened by an inclined piston, we explored the deformation patterns of model upper crust. Specifically, we were interested in the evolution of displacement vector fields, vertical-axis rotations and strain gradients, collectively monitored by digital image correlation, resulting from consecutive phases of shortening with variable directions. In all experiments, we observed the formation of high-amplitude ramp anticlines at the piston, followed respectively by a distinct zone of rhomb-shaped deformation domains and a low-strain zone of rather distributed deformation. As somewhat expected, orthogonal shortening tended to generate symmetric deformation domains enveloped by conjugate model transpression zones, increasing in spacing with distance to the piston. By contrast, highly oblique convergence of the piston generated transpression zones, the geometry and kinematics of which adhered to sets of Riedel shears. Most importantly, the geometry of deformation domains and deformation kinematics change according to the sequence of imposed shortening directions. An added value of the experiments is that one of the lateral margins is unconstrained, allowing shortened material to escape laterally, thereby mimicking indenter tectonics.

Obliquely convergent plate margins and continental collision zones, such as the Andes and Tibet, respectively, are often characterized by crustal-scale, rhomb-shaped basins enveloped by transpression zones. The geometries and sizes of such basins, typically evident as low-strain upper-crustal domains, and their transpressive margins are highly variable. The strength of the viscously deforming lower crust may significantly influence deformation patterns of the upper crust. For this reason, we tested two viscous materials as lower-crustal analogues with regard to the deformational behavior of the model upper crust, induced by a piston driven obliquely into the materials. For modelling a weak lower crust, Laponite, a low-viscosity gel, was used. By contrast, Polydimethylsiloxane (PDMS), a silica polymer, mixed with corundum grains was used for modelling a strong lower crust. Digital image correlation of the top surfaces of experiments allowed us to monitor the evolution of displacement vector fields, vertical-axis rotations and strain gradients. In all experiments, we observed the formation of high-amplitude ramp anticlines above the inclined piston, followed respectively by a well-defined zone of rhomb-shaped deformation domains and a low-strain zone of distributed deformation. In experiments using low-viscosity Laponite mixtures, ramp anticlines with unrealistically large amplitudes formed above the piston. Moreover, rhomb-shaped domains appeared more elongate than in experiments with PDMS, regardless of shortening directions. Apart from the viscosity of modal lower crust, we note that the distance between the piston and the back wall of the modelling box influences deformation patterns significantly, a most important result to be considered in physical experiments.

In the framework of an Arqus Alliance student winter-school in February 2025, geophysical measurements and training was performed at the UNESCO Global Geopark of Granada, in southern Spain. A unique feature in the area are immense palaeontological and archaeological records. The latter has culminated in so far 151 identified megalitic dolmen of copper age (Chalcolithic), forming a network in the Gor river valley, a deeply incised fluvial canyon tributary to the Fardes river.

A peripherical archaeological site is located at the Balneario Alicún de las Torres, a site where travertine limestone platforms and walls have formed by the rise and cooling of deep hydrothermal waters. The calcium carbonate and magnesium sulfate precipitation leads to the formation of naturally formed several meters high aqueducts. However, the origin of these aqueducts are prehistoric ground-level ditches that were used to convey water to a supposed nearby settlement. The dolmens in this area are located nearby the aqueducts, and several geophysical methods, Georadar, Geomagnetics and Geoelectrics have been used to shed light on the hydrological conditions and possible further archaeological remains.

Here we present the first results of these surveys. Geoelectrics revealed the limits between groundwater saturated sediments and dry limestone patches parallel to an old, abandoned travertine aqueduct. Localized high conductivity of the ground may be related to vains of hydrothermal water “leaking” from the aqueduct. Georadar revealed the possible location of another dolmen of similar size and geometry. Furthermore, we show localized magnetic anomalies for discussion of future continuation of this project.

Surficial geochemistry and geophysics are two valuable tools for exploration geologists. In particular, surficial geochemistry, based on the compositional analysis of plant samples, has proven to be an indicator of lithological differences where outcrops are scarce or unavailable. Geophysical methods, such as electromagnetic surveys, offer a non-invasive means of measuring proxies of subsurface lithology. However, interpreting geophysical data requires inversion to produce 3D models, a process that can be improved by incorporating geological knowledge into the inversion algorithms. This knowledge-driven approach can also be supported by the geochemistry of plants.

This study uses data from a test site within the Horizon Europe SEMACRET project, which is located in an orthomagmatic intrusion featuring mineralisations. Data collection aimed to investigate the effectiveness of surficial geochemistry and electromagnetic surveys in detecting shallow and deep-seated mineralisations. The results show that geophysical data inversion and plant geochemistry provide complementary insights into the bedrock, offering a more robust proxy for lithological interpretation together. This study explores the potential of combining surficial geochemistry with geophysical models (resistivity and chargeability), and we present preliminary results from this investigation. This integrated approach has significant implications for exploration geology, exploiting techniques which are applicable even when sample numbers are comparatively low, which would otherwise inhibit classical machine learning-driven prospectivity modelling.

Archeopterodactyloidea are a monophyletic group of early branching Pterosaurians that likely originated in the early to middle Triassic. They are often characterized by their elongated skull and neck as well as their short tail. Their feeding ecology is a much debated topic, describing them to be anything from insectivores to piscivores. Here we attempt to understand their feeding ecology better by trying to quantify skull shape as a possible ecological proxy. A major focus here are differences between immature and adult specimens of the same species and possible implications for their diet. We used Elliptic Fourier Analysis to quantify pterosaurian skulls outlines as a quantitative representation of overall skull shape. Our results show a varying degree of heterochrony for all four species of archeopterodactyloidean pterosaurians in the analysis. This heterochronic change is largely cause by the elongation of the skull throughout ontogeny. Germanodactylus cristatus shows clear differences between short immature skulls and more elongated adult skulls. In Pterodactylus antiquus these differences become even more pronounced. In Aurorazhdarcho micronyx the difference lessens, with more elongated immature skulls. In Ctenochasma elegans these differences are even less pronounced, with already strongly elongated immature skulls. This could either imply early branching archeopterodactyloideans had some sort of ecological niche differentiation between stages or that they were more nidicolous. This then likely changed through phylogeny with different late branching representatives of archeopterodactyloidea being either less ecologically differentiated between stages or possibly being more nidifugous.

Parasites are ubiquitous and an important part of the modern biodiversity, representing at least half of all extant organisms. Many of them play an important role in biological interactions, like in food webs, and in the co-evolution between host and parasite. Parasitism evolved convergently many times in Metazoa, and we can find parasitic forms in all larger lineages of animals. They demonstrate a huge diversity in morphology, niche occupation, or life cycle. Also in Euarthropoda, parasites appeared several times, with better and with less known forms, such as ticks, parasitic wasps, fleas, barnacles, or tongue worms. All of them evolved convergently to a parasitic mode of life. Despite this important diversity in parasitic organisms, they are still overlooked, and many things remain to be understood, especially concerning their evolution. Fossil specimens are often neglected, and several studies focus on observations of living species. In addition, fossil parasites tend to have a lower chance of preservation, because many of them possess small and soft bodies, or they infect internal organs (soft tissue) of their hosts. In Euarthropoda, the fossil record is better than in other lineages due to their cuticle composed of chitin that shows a rather high preservation potential. An exceptional fossil assemblage from the Ordovician of Sweden delivered organisms in beautiful three-dimensional Orsten-type preservation, representing unusual parasitic organisms. Those fossils yield important information about the early specialisation of parasitism during the Palaeozoic.

Eutrophication symptoms are increasingly observed in remote clearwater lakes. A notable example is Lake Stechlin, a deep, endorheic lake in north-eastern Germany. Between 2010 and 2020, the total phosphorus (TP) concentration in the lake increased from ~15 to over 60 µg L^-1, accompanied by a gradual decline in hypolimnetic oxygen concentration. We determined TP concentrations in sediments and soluble reactive phosphorus (SRP) fluxes across the sediment water interface at 54 sites in the lake to determine spatial patterns of sediment P and release dynamics. SRP fluxes strongly increased with depth across all three basins of the lake, despite considerable variation among sites. Littoral sediments played a significant role in the overall phosphorus (P) release, with higher average SRP fluxes observed in June (1.11 mg m²/day) compared to October (0.75 mg m²/day). In contrast, profundal sediments showed higher release rates in October, as anticipated. Notably, about 46% of the surface sediment area is located in water depths of less than 20 meters, underscoring the importance of littoral sediment zones. Importantly, SRP fluxes from profundal sediment depended less on absolute water depth than on the position of the sampling site relative to the oxycline, which differed greatly among lake basins. Overall, our findings point to considerable spatial variability of SRP sediment concentrations and fluxes to the water column, underscoring the importance of considering littoral sediments, which are often overlooked when assessing P release dynamics in lakes.

Understanding drivers of spatial patterns in soil surface temperature is essential to assess ecosystem vulnerability to climate change, particularly in alpine landscapes characterized by pronounced microclimatic heterogeneity that arise from complex topography, elevation gradients, and pedogenic processes. However, the role of underlying soil properties in modulating surface temperature dynamics remains poorly understood. This study investigates diurnal and nocturnal surface temperature patterns across geomorphological units in a European alpine meadow, emphasizing the roles of soil chemical and physical properties.

An intensive three-day field campaign was conducted in July 2024 near Pansier in the French Alps. Surface and subsurface soil temperature and moisture were recorded at 24 locations across five geomorphological units defined based on their solar radiation input and slope position: moraine ridge, moraine slope, alluvial plain, scree footslope, and scree slope. Soil profiles down to ~40 cm were sampled and analyzed for physical properties such as texture, bulk density, rock fragment content, and chemical properties such has soil organic carbon (SOC), total nitrogen (TN), and soil pH.

Distinct surface temperature patterns emerged for each geomorphological unit, with scree slopes exhibiting notable nocturnal variability and pronounced warming. Overall temperature patterns were associated with soil physical properties, especially sand and rock fragment content, rather than chemical properties. This finding was reinforced by the limited improvement in predictive models when chemical properties were included. Our study suggests soil physical properties play a dominant role in regulating surface thermal behavior in European alpine landscapes, and therefore should be preferentially considered in microclimate-based vulnerability assessments.

To investigate the irradiation-induced structural damage in zircon, that may potentially influence dating methods, we exposed zircon samples to swift heavy ions in two different experimental series. To quantify the impact of increasing irradiation, the first series involved irradiation with gold ions (Au⁷⁹⁺) at an energy of 8.6 MeV/u, with target fluences of 1e¹¹, 2e¹¹, 5e¹¹, 1e¹², and 5e¹² ions/cm² at atmospheric pressure and 25 °C on disc-sliced zircon. Since the second series of experiments focused on the influence of pressure as an additional factor, we used a Paris-Edinburgh press combined with a modified (toroidal) large-volume diamond anvil cell (DAC) with diamond windows, which enabled the irradiation of entire zircon grain samples of larger sizes, approximately 2-3 mm. One of these samples was irradiated with uranium ions (U⁹²⁺) at an energy of 480 MeV/u and a pressure of 1.5 GPa at 25 °C.

Using confocal Raman spectroscopy, the focus was on the changes in the FWHM of the ν3(SiO₄) Raman band at approximately 1008 cm⁻¹ as an indicator of structural damage. The peak position exhibited shifts towards lower wavenumbers, and increased peak widths correlated with increasing fluence, showing a strong relationship between ion irradiation and the degree of amorphization. Maps of the samples of the second series show a linear shift of up to 4 cm⁻¹ that is localized exclusively along the irradiation path. However, to more accurately determine the influence of pressure, further analytical methods, such as TEM and EBSD, are still necessary.

The Arabian Nubian Shield is the largest Neoproterozoic juvenile crust on Earth, formed by the closure of the Mozambique ocean during the Pan-African Orogeny which gave rise to the formation of the supercontinent Gondwana. There is a broad consensus that the tectonic processes related to the assembly of Gondwana led to the formation of the numerous gold deposits distributed in the shield. Later in Cenozoic, the shield was dissected by the Oligo-Miocene Red Sea rift into two parts, which are the Nubian Shield which extends through Egypt, Sudan, Eritrea, and Ethiopia and on the other side the Arabian Shield covering large parts of Jordan, Saudi Arabia, and Yemen. The gold deposits include Au-bearing volcanogenic massive sulfide (VMS), orogenic gold, intrusion related gold and rare, but significant deposits described as epithermal gold deposits .

Hamama polymetallic gold prospect in Egypt has been intermittently investigated since 1970s and is traditionally known as Au-bearing VMS. Recent field mapping and extensive drilling by Aton Resources Inc. revealed that the metals are hosted in a horizon termed silica-carbonate-barite (SCB), which is surrounded by 695 Ma submarine metavolcanics. This horizon extends for about 3.2 km in NE-ENE direction, has a thickness of 15 to 40 meters and is intersected in drillholes at an average depth of about 120m. They estimated the inferred gold and silver resources from the Hamama West prospect at about 230 and 7,836 koz., respectively. Previously, and until recently, the SCB was believed to be a part of the Neoproterozoic submarine environment. The main debate has mainly revolved around its nature, whether it is an exhalative sedimentary rock or a felsic volcanic that suffered carbonatization.

We conducted two field trips and obtained representative borehole specimens to apply a more detailed work. We discovered that the SCB is a previously unreported sedimentary formation of Late Cretaceous entrapped between the Neoproterozoic metavolcanic piles. The conspicuous time gap was affirmed by field relations, first-time observed fossils and petrographic characters that aligns with the newly proposed model. The presentend findings argue against the deposition of Au in the shield merley in Precambrian.

There is an urgent need to include Earth system sciences in the school curricula in order to enable the next generation to understand the basics of the Earth as a dynamic system and its global problems such as climate change or the sustainable use of georesources. In order to support school and student training but also for people who are generally interested in natural sciences and in particular in geoscience, I have created a whole series of websites and educational videos over the last four years, which are part of my collection of teaching materials that can be found on the DGGV website. Educational videos on my YouTube channel "Lehrvideos System Erde" (Educational videos on the Earth System) are integrated into the web pages. All texts, images and movie clips used in the videos can be downloaded free of charge and for free use. This web-based teaching material is particularly suitable for teachers in schools, but is also intended for students and interested laypeople.

The series is under construction, with 20 websites and videos completed so far. The chapters are currently available in English and German; Spanish will be added as a third language soon. The 20 completed chapters cover the structure of the Earth, isostasy, the development of the oceanic crust and lithospheric mantle, divergent plate boundaries, transform faults, the Earth´s magnetic field, and the geometry of plate movements. More websites and videos will follow soon.