Conference Agenda

Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).

Session Overview
Poster social - Themes: 1.03 | 1.07 | 1.09 | 1.21 | 1.22 | 1.23 | 1.27 | 1.29 | 2.06 | 3.06 | 3.16 | 3.27 | 3.28 | 4.08 | 4.09 | 4.10
Tuesday, 05/Sept/2023:
5:30pm - 7:00pm

Location: Foyer (Henry Ford Building)

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Tue: 1
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Quaternary fault reactivation in Antarctica associated with Glacial Isostatic Adjustment

Ingra Malucelli Barbosa1, Holger Steffen2, Rebekka Steffen2, Elisabeth Seidel1, Karsten Gohl3, Christian Hübscher1

1Institute of Geophysics, University of Hamburg, Hamburg, Germany; 2Geodetic Infrastructure, Lantmäteriet, Gälve, Sweden; 3Alfred Wegener Institute Helmholtz-Centre for Polar and Marine Research, Bremerhaven, Germany

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

Tue: 3
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Combined analysis of H/V and passive seismic array measurements to investigate the shallow underground of the Quaternary Weser terraces south of Hamelin

Manuel Hobiger1, Christine Thiel1, Thomas Spies1, Koen Van Noten2, Martin Zeckra2, Aida Azari Sisi1, Andreas Steinberg1, Stefanie Donner1

1Federal Institute for Geosciences and Natural Resources, Federal Seismological Survey, Hanover, Germany; 2Royal Observatory of Belgium, Seismology-Gravimetry, Brussels, Belgium

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

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

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

Tue: 4
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Multi-Method Geophysical Investigation of Fault Structures in the Northern Upper Rhine Graben: Insights from the NeoNORG Project

Johannes Mair1,2, Hermann Buness3, Andreas Henk2, Rouwen Lehné4, Lajos Röhlinger2

1BfS (German Federal Office for Radiation Protection), UR2, Berlin, Germany; 2Technical University of Darmstadt, Institute of Applied Geosciences, Darmstadt, Germany; 3Leibniz Institute for Applied Geophysics (LIAG), Hannover; 4Hessian Agency for Nature Conservation, Environment and Geology, Wiesbaden, Germany

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

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

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

Tue: 5
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Full microtremor H/V and phase velocity dispersion curves inversion for S-wave velocity profiles of subaqueous slopes in Lake Lucerne (Switzerland)

Agostiny Marrios Lontsi1,2, Anastasiia Shynkarenko2, Donat Fäh2

1Department of Civil and Architectural Engineering, Faculty of Engineering and Technology, University of Buea, Buea, Cameroon; 2Swiss Seismological Service, Swiss Federal Institute of Technology, Zurich, Switzerland

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

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

Tue: 6
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

Determination of seismic resolution: Some practical aspects from land seismic data

Patrick Musmann

BGR, Germany

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

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

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

Tue: 7
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

The reactivated intraplate Osning Lineament in northern Germany – Near-surface investigations using P- and SH-wave reflection seismics

Sonja Halina Wadas, David Colin Tanner

Leibniz Institute for Applied Geophysics, Germany

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

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

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

Tue: 8
Topics: 1.03 Exploration of near-surface geological structures using active and passive seismic methods

A multi-seismic approach to characterize the shallow subsurface for hosting the Einstein-Telescope infrastructure

Marius Waldvogel1, Nils Chudalla2, Shahar Shani-Kadmiel3, Soumen Kouley4, Stefan Back5

1Geological Institute, RWTH Aachen University, Germany; 2Institute for Applied Geophysics and Geothermal Energy, RWTH Aachen University, Germany; 3Royal Netherlands Meteorological Institute (KNMI); 4Gran Sasso Science Institute; 5Geological Institute, RWTH Aachen University, Germany

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

Tue: 10
Topics: 1.21 Distribution, reactivity and behaviour of TCEs in aquatic systems: surface-, ground-, hydrothermal- waters and brines

Colloidal transport and seasonal variations of technology critical elements in aquatic systems

Teba Gil-Díaz1,2, Elisabeth Eiche1,2

1Karlsruhe Institute of Technology (KIT), Institute of Applied Geosciences, Adenauerring 20b, 76131 Karlsruhe; 2Laboratory for Environmental and Raw Materials Analysis, Institute of Applied Geosciences, Karlsruhe Institute of Technology, Karlsruhe

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


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

Tue: 11
Topics: 1.21 Distribution, reactivity and behaviour of TCEs in aquatic systems: surface-, ground-, hydrothermal- waters and brines

Understanding the potential mobility of geogenic metals of concern from heavy mineral sands

Christoforos Zamparas1, Teba Gil-Díaz1, Dieter Schild2, Elisabeth Eiche1

1Karlsruhe Institute of Technology (KIT), Institute of Applied Geosciences, Adenauerring 20b, 76131 Karlsruhe, Germany; 2Karlsruhe Institute of Technology (KIT), Institute for Nuclear Waste Disposal, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany

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


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

Tue: 13
Topics: 1.22 Contaminants in groundwater – curse and blessing

GCI Rohrpassivsammler – An innovation for the integrative monitoring of water quality

Jörg-Helge Hein

GCI GmbH, Germany

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

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

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

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

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

Tue: 14
Topics: 1.22 Contaminants in groundwater – curse and blessing

Influence of pH and Na-concentration on facilitated and hampered transport of metoprolol by montmorillonite colloids in water-saturated quartz sand

Joshua Sawall1, Wiebke Warner2, Tobias Licha2, Ferry Schiperski1

1Technische Universität Berlin, Institute of Applied Geosciences, Dept. of Applied Geochemistry, 10587 Berlin, Germany; 2Ruhr-Universität Bochum, Institute of Geology, Mineralogy and Geophysics, Dept. of Hydrogeology-and -chemistry, 44801 Bochum

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

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

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

Tue: 16
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Groundwater monitoring in Niamey, Niger: Is groundwater an alternative drinking water supply under the current quality conditions?

Issa Bakayoko1, Didier Zinsou2, Manal Wannous1

1Federal Institute For Geoscience and Natural Resources BGR, Germany; 2Directorate of Niger Basin Authority

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

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

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

Tue: 17
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Assessing and improving the groundwater quality monitoring network of the State of Brandenburg, Germany

Florian Jenn1, Patrick Wieder1, Silvia Dinse1, Tania Birner2, Ute von Daacke2

1GCI GmbH, Königs Wusterhausen, Germany; 2Landesamt für Umwelt Brandenburg, Potsdam, Germany

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

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

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

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

Tue: 18
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Inferring deep soil moisture variations in Central and Southern Europe using seismic method

Yang Lu1, Qing-Yu Wang2, Götz Bokelmann1

1University of Vienna, Austria; 2Massachusetts Institute of Technology, USA.

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

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

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

Tue: 19
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Model-based impact study of forest restructuring on groundwater recharge and hydrodynamics in a waterworks catchment (Briesen, Brandenburg, Germany)

Franziska Mehler1, Felix Möhler1, Matthias Clausen2, Ines Schwenzer2

1GCI GmbH, Germany; 2FWA Frankfurter Wasser- und Abwassergesellschaft mbH, Germany

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

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

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

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

Tue: 20
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Climate projections for the waterworks Lindau in Saxony-Anhalt as planning basis for proactive and sustainable catchment management

Felix Möhler, Alexandra Pavlova

GCI GmbH, Germany

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

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

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

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

Tue: 21
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Case study at a model site "Green Economy Park" in Bremerhaven, Germany "Luneplate": High resolution 3D subsurface models in flow modeling with a focus on climate resilience

Katherina Seiter, Björn Panteleit, Sina Julius

GeologicalSurvey Bremen (GDfB), Germany

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

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

Tue: 22
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Managed Aquifer Recharge for sustainable development in the Northern Coastal Aquifer System of Sinai Peninsula, Egypt

Ashraf Sayed Seleem1, Mona Morsy2, Peter Dietrich3

1Geology Department, Faculty of Science, Suez Canal University, Ismailia, Egypt; 2Geology Department, Faculty of Science, Suez Canal University, Ismailia, Egypt; Department; Monitoring and Exploration Technologies, Helmholtz Center for Environmental Research GmbH — UFZ; Geo- and Environmental Sciences, University of Tübingen.; 3Department; Monitoring and Exploration Technologies, Helmholtz Center for Environmental Research GmbH — UFZ; Department of Geosciences, Soil Science and Geomorphology, University of Hannover; Geo- and Environmental Sciences, University of Tübingen.

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

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

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

Tue: 23
Topics: 1.23 Sustainable Groundwater Management to mitigate Water Scarcity: Innovative monitoring strategies, new modelling tools, and integrative management concepts

Evaluation of geogenic and anthropogenic impacts on spatio-temporal variation in the quality of the drinking water sources under the impact of land-use and land-cover: A case study of the Erbil Central Sub-Basin, Iraq

Jawhar Mohammed-Shukur TAWFEEQ1, Erkan DİŞLİa1, Masoud Hussein HAMED2

1Department of Environmental Engineering, Faculty of Engineering, Van Yuzuncu Yil University, Van, Turkey; 2Department of Geology, College of Science, University of Salahaddin, Erbil, Iraq

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

Tue: 24
Topics: 1.27 Young Scientist Session

Kinematic analysis of a left step over along the dextral Kallar Kahar Fault, Salt Range, Pakistan.

Nowrad Ali1,2, Azmatullah Orakzai3, Asghar Khan3

1Institute of Geosciences, University of Potsdam, Germany; 2Department of Geology, University of Peshawar, Pakistan; 3Department of Geology, Shaheed Benazir Bhutto University, Sheringal Dir Upper, Pakistan

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

Tue: 25
Topics: 1.27 Young Scientist Session

Daily growth rate quantification in fossil giant clam shells with Daydacna

Iris Arndt1,2, Douglas Coenen1,2, David Evans3, Willem Renema4,5, Wolfgang Müller1,2

1Goethe University Frankfurt, Germany; 2Frankfurt Isotope and Element Research Center (FIERCE), Frankfurt am Main, Germany; 3University of Southampton, Southampton, U.K.; 4Naturalis Biodiversity Center, Leiden, The Netherlands; 5University of Amsterdam, Amsterdam, The Netherlands

Tridacna shells feature macroscopically visible bands (at mm scale) as well as microscopically visible daily banding (at µm scale). To evaluate the lifespan of an individual, the presumably seasonal macroscopically visible bands can be counted, or stable oxygen isotope analysis can be used to identify seasonal cycles. However, these approaches may not always be conclusive, especially for Tridacna which at times display irregular seasonal growth patterns and often grow in equatorial areas with low seasonal SST variability and heavy seasonal precipitation, influencing δ18O seawater values. Counting the daily bands (manually or with software-based image analysis) gives a more accurate internal age model with high temporal resolution, but daily banding is not always visually retrievable in fossil specimens, hampering the production of a precise age estimate. We show that daily geochemical cycles can be measured with highly-spatially resolved laser-ablation inductively coupled plasma mass spectrometry (LA-ICPMS; 3 x 33 µm laser slit) in our Miocene (~10 Ma) specimen, even in areas where daily banding is not visible. We present a python script Daydacna, in which we use wavelet transformation on the measured daily geochemical cycles to quantify varying daily growth rates throughout the shell. This provides a robust alternative to visual band counting. The resulting age model can be used to quantify seasonal growth rate variability over several decades and provide a basis for time resolved sub-seasonal paleoenvironmental proxy evaluation.

Tue: 26
Topics: 1.27 Young Scientist Session

Mineral material for use in dermocosmetic products based on a modification kaolin from the Jegłowa deposit (Poland)

Anna Czarnecka-Skwarek, Agnieszka Rożek, Michał Pilaszkiewicz

University of Warsaw, Poland

The aim of the research was to produce a microbiologically safe, modified mineral material with increased sorption parameters, enabling use in the cosmetics industry as an active substance in the line of dermocosmetic products. Samples of selected kaolin (from the Jegłowa deposit, part of Silesia, Poland) were subjected to thermal (at 600 ℃) and chemical activation (using 2 or 4 M HCl). The modified material was characterized using the XRD, SEM and gas porosimetry methods (the specific surface of the samples was determined based on the assumptions of the BET model). The microbiological purity of the newly manufactured materials has been tested in accordance with the applicable standards ISO 21149:2017-07 (for bacteria) and ISO 16212:2017-08 (for yeasts). The results showed that both modifications affected the structure and properties of the tested samples. The acid activation caused the displacement and increase in the intensity of XRD reflections of kaolinite, which is the result of the removal of poorly crystalline mineral phases from the sample, present in unmodified samples. SEM imaging confirmed the change in the morphology of kaolinite plates. The measured surface properties of the samples (specific surface area, micropore area) were significantly higher in the case of acid activation and increased with the use of a stronger acid (4M HCl). Microbiological tests have shown that both the thermally and acid-activated samples meet the quality requirements for materials used in the dermocosmetics. The conducted research proves that kaolin from Jegłowa can be an attractive raw material for the cosmetics industry.

Tue: 27
Topics: 1.27 Young Scientist Session

Leaf-wax n-alkane composition of an extinct Middle to Late Jurassic plant assemblage dominated by bennettitaleans

Lisa von Nolting1, Alexander Rohrmann2, Christian Pott3, Baoyu Jiang4, Manja Hethke1,3

1Fachrichtung Paläontologie, Institut für Geologische Wissenschaften, Department Geowissenschaften, Freie Universität Berlin; 2Fachrichtung Tektonik und Sedimentäre Systeme, Institut für Geologische Wissenschaften, Department Geowissenschaften, Freie Universität Berlin; 3LWL-Museum für Naturkunde, Westfälisches Landesmuseum mit Planetarium, Referat Paläontologie, D-48161 Münster, Germany; 4Center for Research and Education on Biological Evolution and Environments, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China

Leaf-wax n-alkane concentrations and average chain lengths (ACL) significantly vary among extant gymnosperm groups. When investigating deep-time archives, further plant groups need to be considered that since went extinct. Also, entirely aquatic plants, as known in the angiosperm clade, are not known to be amongst any fossil or extant gymnosperm group. The Middle to Late Jurassic macroplant assemblage preserved in the volcanic lake deposits of the Haifanggou Formation in Inner Mongolia, China, and attributed to the Yanliao Fossillagerstätte, reflects such a gymnosperm-dominated environment, amongst which the extinct Bennettitales constituted the dominant seed-plant component, with ginkgophytes and cupressoid conifers as additional major components. This fossil environment existed c. 35 million years prior to the rise of the angiosperms. The current study examines the relative n-alkane concentrations preserved in 33 samples from two excavations in the Haifanggou Formation. Despite the high age of the sampled strata, n-alkane preservation is excellent. In addition, the two excavations yield mean ACL25–37 values of 28.2 and 27.8, respectively, and the n-alkane distributions are dominated by n-C27 alkanes and, in some samples, by n-C25 alkanes. Thus, given that Bennettitales were the dominant plant group in the assemblage, we hypothesize that bennettitalean cuticles were composed of n-alkanes with relatively short chain lengths compared to extant gymnosperm groups. To corroborate this hypothesis, further verification through direct analysis of well-preserved fossil cuticles of Bennettitales is warranted.

Tue: 28
Topics: 1.27 Young Scientist Session

Climatic Impact of the Little Ice Age on Sumatra, Indonesia

Franziska Schwonke1, Alexander Rohrmann1, Anne Bernhardt1, Katleen Wils2

1Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany; 2Renard Centre of Marine Geology (RCMG), Department of Geology, Ghent University, Ghent, Belgium

The Little Ice Age was a period of colder climate and extended glaciation mainly observed in Europe and North America between the middle of the 14th and the end of the 19th century. However, the climatic impact of the Little Ice Age on tropical regions is still unclear. In this study, we sampled two short (1m), dated sediment cores (MJ17-01A-G and MJ17-01B-G) that were taken in 2017 within Lake Maninjau for leaf wax compound-specific analysis. Lake Maninjau is a 99.5 km2 caldera lake located at the equator in the Padang Highlands on the Island of Sumatra, Indonesia. Here, we extracted leaf-wax compounds of 34 samples – so called n-alkanes – measured their concentration and calculated the average chain length (ACL) and carbon preference index (CPI) of the individual samples. The ACL is a first-order proxy for overall humidity/precipitation and ranges between carbon numbers of C26 and C31 with a trend to lower values towards the top of the section. We interpret this shift from higher to lower ACL-values to represent a shift from dryer to more humid conditions between 1550 and 1850 AD in the period of the Little Ice Age and into the modern. We interpret that the Little Ice Age in Europe and North America indeed also affected tropical regions like Southeast Asia.

Tue: 29
Topics: 1.29 Breakthrough technologies and innovations along the mineral raw materials supply chain - towards a sustainable and secure raw material supply

Bioleaching of Rare Earth Elements from Primary Resources using Heterotrophic Organisms

Debby Schmidt1, Uwe Altenberger2, Sabine Kutschke3

1Universität Potsdam; 2Universität Potsdam; 3Helmholtz-Institut Freiberg für Res­sourcen­tech­no­logie

Rare earth elements (REE) are essential for various modern "green" technologies. However, conventional mining and extraction methods for REEs are energy-intensive, environmentally harmful, and call for the evaluation of alternative extraction procedures for these critical raw materials. Bioleaching processes have been successfully employed in the industrial extraction of metals and offer a promising and eco-friendly approach to enhance the sustainability of REE extraction. This study evaluates the potential of bioleaching REEs from unprocessed carbonatitic and alkaline bulk rocks.

Batch and supernatant leaching experiments were conducted on a Carbonatite sample from the Fen-Complex (Norway) and two nepheline syenites (a Grennatite and a pegmatitic Grennaite from Norra Kärr, Sweden), utilizing the heterotrophic organisms Yarrowia lipolytica and Tea fungus Kombucha. The influences of bulk mineralogy on microbial growth and metabolite production, as well as leaching rates and applicability of the different approaches were assessed.

The results demonstrate varying recovery rates based on mineralogy and leaching methods, with preferential leaching of light or heavy REEs depending on the selected organisms. Notably, the highest leaching efficiency of 54% REE recovery was achieved with Y. lipolytica supernatant leaching on pegmatitic Grennaite during a 19-day experiment. Carbonatite and Grennaite samples exhibited lower maximum leaching rates of 5% and 8%, respectively.

The findings demonstrate the proof-of-concept feasibility of bioleaching REEs from unprocessed bulk rock materials and highlight its strong potential, especially in providing a sustainable solution for utilizing low-grade ores and mine waste.

Tue: 30
Topics: 1.29 Breakthrough technologies and innovations along the mineral raw materials supply chain - towards a sustainable and secure raw material supply

New advances in particle size and shape measurements using complementary optical technologies based on dynamic image analysis

Andre Klicpera

Microtrac Retsch GmbH, Germany

Determination of particle size distribution of sediments and soils is a crucial property in several fields of industry and geoscientific research. The consequence of improper analyses can result in poor product quality, high rejection rates, or incorrect research data.

Most currently used particle sizing methods such as laser diffraction, sieve analysis or microscopy, are established over decades or even centuries and have been deployed in many different fields. However, their significance is often limited due to low resolution, limited capabilities in terms of quality control requirements or simply the lack of particle shape information. The concept of imaging particle analysis is a relatively new technology, dating back to the late 1970s as CCD sensors for capturing and computers for processing image data began to evolve. Further developments such as Dynamic Image Analysis (DIA) based on one or two high-speed cameras provided enhanced access to morphological particle size and shape information in high-resolution and with statistical robustness by a simple measurement of usually less than three minutes.

Here we introduce two new technologies in the context of dynamic image analysis. Designed as a hybrid-laser diffraction particle-analyzer, the Microtrac Sync provides conventional laser-based optics, equipped with a digital camera for precise particle size and shape information.

Another ground-breaking technology comes with the new Camsizer3D. It uses particle tracking technology, allowing to follow each particle of a sample in up to 30 different orientations. The resulting high-resolution 3D dataset provides digital size and shape information of real morphological particle geometries.

Tue: 31
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Redox state and interior structure control on the long-term habitability of stagnant-lid planets

Philipp Baumeister1,2, Nicola Tosi1,3, Caroline Brachmann1,3, John Lee Grenfell1, Lena Noack3

1Institute of Planetary Research, German Aerospace Center (DLR), Germany; 2Department of Astronomy and Astrophysics, Technische Universität Berlin, Germany; 3Department of Earth Sciences, Freie Universität Berlin, Germany

A major goal in exoplanet science is the search for planets with the right conditions to support liquid water. The habitability of a planet depends strongly on the composition of its atmosphere. Interiors and atmospheres of rocky planets are linked through feedback processes and evolve as a coupled system. In particular, volcanic outgassing shapes the atmospheric composition, but the exact composition of outgassed species not only depends on the volatile content and redox state of the mantle, but also on the current state of the atmosphere.

In an extensive parameter study of rocky exoplanets, we investigated the emergence of habitable surface conditions for a wide range of initial conditions, including the planet mass, interior structure, volatile content and redox state. The model accounts for the main mechanisms controlling the long-term evolution of stagnant-lid rocky planets (i.e. bodies without plate tectonics). It includes a large number of atmosphere-interior feedback processes, such as a CO2 weathering cycle, volcanic outgassing, a water cycle between ocean and atmosphere, greenhouse heating, as well as escape processes of H2.

We find that only a narrow range of the mantle redox state around the iron-wüstite buffer allows forming atmospheres that lead to long-term habitable conditions. At more oxidizing conditions, most planets instead end up in a hothouse greenhouse state (akin to Venus) due to strong CO2 outgassing. On the other hand, on planets with more reducing mantles, the amount of outgassed greenhouse gasses is often too low to keep the surface above the freezing point of water.

Tue: 33
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Modelling thermal evolution of molten and tidally heated Io-Like planetary mantles

Mathilde Kervazo, Lena Noack, Enrique Sanchis

Freie Universitat, Germany

Internal heating in rocky bodies shape their interior and surface characteristics as well as their evolution. Among internal heat sources, tidal dissipation is a key one. The most striking evidence in the Solar System is the case of Io, archetype of tidally-heated world hosting extreme volcanism.

Io’s internal dynamics is complex due to the large and tidally-produced heat flux, leading to widespread melting in the interior. For Io-like bodies, the dissipation and heat transport models have thus to incorporate interactions between solid and liquid phases. Io’s mantle is commonly modelled either as a solid convective mantle, adapting models of terrestrial planets, or as a fluid magma ocean, adapting models of fluid water oceans of icy moons. However, neither of these two classifications likely accurately describes Io’s partially molten interior.

In that context, we model Io's mantle thermal evolution following the work of Sanchis et al (2022, EPSC), who developed a magma ocean modelling, using the CHIC convective code (e.g. Noack et al. 2013, Infocomp). In addition, we take into account heat generated by tidal dissipation accounting for the effect of melt presence on the viscous and elastic parameters of the mantle following Kervazo et al. (2021).

Our study provides valuable insights into the role of a large amount of melt in the thermal evolution of rocky planets and moons, and our modeling approach is applicable to other rocky planets with hot interiors, including the Trappist-1 planets and various known rocky exoplanets.

Tue: 34
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Kinetic Deflection of an asteroid: Impact Simulations of the DART impact in a heterogeneous target

Robert Luther1, Mallory DeCoster2, Dawn M. Graninger2, Emma S. G. Rainey2, Angela Stickle2, Sebastian Baldauf1, Kai Wünnemann1,3

1Museum für Naturkunde Berlin, Germany; 2Johns Hopkins University - Applied Physics Lab; 3Freie Universität Berlin

On 26th of September 2022, NASA’s DART spacecraft impacted the secondary of the Didymos system, Dimorphos [1]. Its impact shortened the orbit of Dimorphos by 33 minutes to 11.37 h [2]. The change of the orbit is caused by a change of Dimorphos’ momentum due to the impact. A fraction of the momentum-change related to the transfer of the spacecraft momentum. The more important fraction of momentum is caused by the ejection of material from Dimorphos. The momentum-enhancement-factor β for vertical impacts is defined as β=1+pEj/pImp, with the ejecta and impactor momentum pEj and pImp, respectively, and was predicted to fall between ~2 and 5, based on impact simulations into homogeneous materials, [3,4,5]. The estimates for β depend on Dimorphos’ properties. For a density of 2400 kg/m³, the estimate is β = (1σ) [6]. Recent studies have shown that heterogeneities in the target (e.g. boulders) affect material ejection and β [7, 8]. In this study, we use impact models to simulate the DART impact with 1-10m-sized boulders, and we test the influence of a potential stronger and denser subsurface layer on β. We find an increase of beta by ~5% for such a subsurface layer in 5m depth, so that we conclude that heterogeneities in >5m depth do not affect β.

We acknowledge the computing time provided for our project bek00041on the supercomputer Lise and Emmy, part of the NHR infrastructure.

[1]Daly et al.(2023),Nature616,443.[2]Thomas et al.(2023),Nature616,448.[3]Raducan et al.(2019),Icarus329,282-295.[4]Stickle et al.(2022),PSJ 3:248.[5]Luther et al.(2022),PSJ3:227.[6]Cheng et al.(2023),Nature616,457.[7]Ormö et al.(2022),EPSL594,117713.[8]Raducan et al.(2022),A&A 665,L10.

Tue: 35
Topics: 2.06 Interior, surface and atmosphere processes on rocky worlds

Critical external and internal factors for plate tectonics

Oliver Henke-Seemann, Lena Noack

Freie Universität Berlin, Germany

Convective mantle flow in terrestrial planets is governed by a temperature- and pressure-dependent rheology. This results in a stagnant-lid regime observed on most terrestrial planets. Plastic deformation can lead to breaking of the strong upper lithosphere, which resembles plate tectonics on Earth. Most efforts to model mantle convection with self-consistent plate tectonics combine Newtonian diffusion creep with a stress-dependent pseudo-plastic rheology in the form of a yield criterion. However, in the uppermost mantle, where stresses are high, deformation is thought to be driven in large parts by deformation via dislocation creep. As numerical models get more robust and capable of more complexity, viscoplastic models should therefore include non-Newtonian dislocation creep.

In our models we employ a composite viscosity, combining both Newtonian and Non-Newtonian power laws in a viscoplastic approach. We study the influence of varying rheologies on plate tectonics simulations, by testing several internal and external parameters, such as grain size and surface temperature. In a 2D-spherical annulus geometry we employ an interior structure model for an Earth-like planet to obtain local information on thermodynamics properties of the main minerals present in Earth’s mantle. We evaluate the models by computing common diagnostic values used to recognize plate-like surface deformation. The goal of this study is to identify key planetary factors for the occurrence or absence of plate tectonics.

Tue: 36
Topics: 3.06 Present and past sediment routing systems

Provenance changes in NW Borneo and the development of the Miocene Baram Delta: implications from detrital zircon geochronology and heavy mineral analysis

H. Tim Breitfeld1, Juliane Hennig-Breitfeld1,2, Thomson Galin3

1TU Bergakademie Freiberg, Germany; 2SE Asia Research Group, Royal Holloway University of London, UK; 3Department of Mineral and Geoscience Malaysia, Sarawak

The Cenozoic of Borneo consists of thick clastic sedimentary rocks that were deposited in various fluvial-lacustrine, shallow marine and deep-marine settings. From the Eocene onwards, the sedimentary successions play an important economic role. Onshore, Eocene sediments comprise coal seams of commercial interest, while Miocene deposits offshore are important hydrocarbon reservoirs. In principle there are two main sediment sources that have contributed to the successions. The Cretaceous arc-related Schwaner Mountains in the south of the island, and the Triassic tin belt granites from the Malay Peninsula. Characteristic detrital zircon U-Pb ages and heavy mineral signatures reveal a change of these sources through time, related to major tectonic developments, such as the opening of the South China Sea. The Miri Zone in NW Borneo consists of Eocene turbidites of the Rajang Group, unconformably overlain by tidally-influenced delta deposits of the Oligocene Nyalau Formation. The Rajang Group turbidites overall reveal a provenance related to the Schwaner Mountains, while the Nyalau Formation indicates a Malay tin belt source, bypassing southern Borneo. The Miocene deposits of the Baram Delta form the youngest successions of the Miri Zone, and comprise fluvial, tidal, deltaic and shallow marine deposits. They are the analogue for the hydrocarbon reservoir offshore Brunei and northern Sarawak. In contrast to the underlying Nyalau Formation, the Baram successions were sourced directly from uplifted Rajang Group tubidites from the interior of Borneo. Thus, studying compositional variations and provenance characteristics help to understand sources and sedimentary routing pathways.

Tue: 37
Topics: 3.06 Present and past sediment routing systems

Provenance of Paleozoic diamictites in the southern Black Forest: petrography, geochemistry and detrital U-Pb-zircon chronology

Calvin Diehl1, Johannes Lukas1, Henri Paul Meinaß1, Armin Zeh2, Matthias Hinderer1

1TU Darmstadt, Germany; 2Karlsruhe Institute of Technology, Germany

In the Badenweiler-Lenzkirch Zone (BLZ) of the southern Black Forest, lower Paleozoic metasedimentary rocks of the Sengalenkopfschiefer Formation contain intercalations of diamictites which have been linked to the Hirnantian glaciation. This interpretation is based on lithological arguments and rare palynological remains showing Ordovician to Devonian Acritarch and Chitinozoa associations. This interpretation is challenged by new results of U-Pb dating of detrital zircon grains from four samples of diamictites and associated fine-grained schists. The diamictite layer consists of strongly elongated clasts up to 5 cm in diameter, comprising vein quartz, volcanic detritus, pelites, and minor magmatic pebbles. In total 509 detrital zircon grains were dated by LA-ICP-MS at KIT. These reveal similar age spectra for all four samples, characterized by significant age peaks at ~ 380 Ma, ~ 400 Ma, ~ 480-500 Ma, ~ 600-620 Ma, ~ 700-750 Ma and ~ 1.8-2.2 Ga, and ~ 2.6 Ga, and very small peaks at 0.9-1.1 Ga. The pre-Silurian age populations correspond to the spectra of West Gondwana with minor Mesoproterozoic and very minor Grenville zircons (ca. 1.0 Ga). The two younger age populations fit to a subduction model with an active magmatic arc and published ages for the adjacent Randgranite nappe. The youngest zircon grains reveal maximum depositional ages of ca. 360 Ma, which is close to the Devonian-Carboniferous boundary. This discards the former assumption of Hirnantian glaciation. Instead we hypothesize that the diamictites are linked to the Upper Devonian glaciation which affected North America, South America and West Africa.

Tue: 39
Topics: 3.16 Assessing biosphere geosphere interactions in the subsurface, at leaking wells, and natural vents and seeps

Methane emission and microbial oxidation at buried abandoned wells in Northern Germany

Sebastian F. A. Jordan, Stefan Schlömer, Martin Krüger, Martin Blumenberg

Federal Institute for Geosciences and Natural Resources, Germany

As we are risking to exceed the 1.5-degree target in the next decade, effective measures to cut back greenhouse gas emission are necessary. Methane became the focus of attention as the target to mitigate global warming, since the mean atmospheric lifetime of this strong greenhouse gas is at least an order of magnitude shorter than carbon dioxide. Here we will focus on the oil and gas sector, which represents the second largest anthropogenic methane source after agriculture. Abandoned oil and gas wells are seen as important targets, since they can (in some cases) emit up to several tons of methane per day. However, only about a dozen countries have measured data on methane emissions and even less include it in their yearly greenhouse gas inventory. Germany has about 20,000 abandoned wells, which are generally filled and buried, however, it is unclear, whether they are emitting methane or not.

Here, we present an overview of methane emission and microbial methane turnover at about 50 onshore oil and gas wells in Northern Germany covering both abandoned exploration and production wells. Using isotopic methane composition we were able to link the methane emissions at three well sites in an active peat-cutting area to methanogenesis. Furthermore, elevated potential methane oxidation rates suggest that the majority of the microbially formed methane was oxidized before reaching the atmosphere. Our data demonstrates the necessity for detailed knowledge on methane cycling and background emissions to assess abandoned wells, particularly in areas where natural methanogenesis is present.

Tue: 40
Topics: 3.06 Present and past sediment routing systems

Inversion of an open-source forward stratigraphic model: a case study from the Bengal Fan

James M. Lovell-Kennedy, Peter Burgess

QUEST, Department of Earth, Ocean and Ecological Sciences, University of Liverpool, United Kingdom

Inverting forward models to constrain output against data is critical for predicting and understanding sedimentary systems. We present an open-source workflow using SciPy functions to invert a Python Badlands model with spatially variable tectonic and rainfall parameters.

Tectonic uplift and rainfall maps are input to model surface uplift, erosion, transport and sediment deposition across the model grid. A SciPy function optimises against an objective function to calculate error and invert the model to find the optimal tectonic and rainfall parameters required to reproduce key aspects of the observed strata.

The workflow has four steps:

  1. Collate paleoDEM’s, paleogeographic, thermochronological and climatic data to create initial topography, tectonic uplift and rainfall input maps

  1. Run the Badlands forward stratigraphic model to calculate evolving topography and basin-fill strata

  1. Use an objective function to calculate error from the comparison of model output and observed stratal properties

  1. Use SciPy to iteratively optimise parameters through steps 2 and 3 to minimize model error

This approach generates a useful series of best-fit models for the Bengal Fan source-to-sink system. The nature of the objective function reveals important aspects of the model behaviour and indicates that climatic factors increasing erosion and sediment yields were the main forcing of Miocene deep-water sedimentation in the Bengal Fan.

Tue: 42
Topics: 3.27 Alkaline rock and carbonatite related magmatism

The Kuboos-Bremen Line in Namibia and South Africa: new insights about emplacement and composition

Jorge Correia Leite Arthuzzi1,2, Benjamin F. Walter1,2, Robert Johannes Giebel3,4, Lorenz Kemmler3, Jochen Kolb1,2

1Karlsruhe Institute of Technology (KIT), Chair of Geochemistry and Economic Geology, Adenauerring 20b, 76131 Karlsruhe, Germany; 2Laboratory of Environmental and Raw Material Analyses (LERA), Adenauerring 20b, 76131 Karlsruhe, Germany; 3Technische Universität Berlin, Institute of Applied Geosciences, Ernst-Reuter-Platz 1, 10587 Berlin, Germany; 4University of the Free State, Department of Geology, 250 Nelson-Mandela-Drive, Bloemfontein 9300, South Africa

The Kuboos-Bremen Line (KBL) is an alignment of intrusions that extent for 250 km in South Africa and Namibia. Its deepest exposed parts occur near Alexander Bay (RSA) and it continues into the continent trending SW-NE, with the higher intrusion level at the Great Karas Mountains (NAM).

The KBL complexes are divided in three sections: Western KBL is predominantly granitic; Central KBL is composed of granites, syenites, foid-syenites and carbonatites; and Eastern KBL is composed of a field of more than a hundred small carbonate-bearing intrusions (carbonatite dykes, sills and breccia pipes, and lamprophyre and alnöite dyke swarms).

The project aims to understand the genetic relationship between the variety of lithologies at the KBL by: investigating whether the behavior of HFSE and REE in carbonatitic magmas is influenced by source contamination and silicate wall-rock interaction; investigating the cross-cutting relationships of individual complexes and their age data, to understand the progressive evolution from granitic to foid-syenitic/carbonatitic compositions with time and location; and study the rock associations to establish if different magma suites derived from one or variable sources and also if they used the same zone of weakness for ascent and emplacement.

After field work and sample collection from all main complexes the first results from geological mapping and petrography show an even broader variety of lithologies than expected. Individual units from individual complexes share textural and mineralogical similarities and also provide us hints of the role of crustal assimilation in the genesis and magmatic to hydrothermal evolution of these rocks.

Tue: 43
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Disclosing the magma genesis and storage beneath the Cretaceous Ebersbrunn diatreme, Saxony: Evidence from mineral chemistry and juvenile fragments

Hripsime Gevorgyan1, Alexander Repstock2, Irka Schüller3, Horst Kämpf3

1TU Bergakademie Freiberg, Institute for Mineralogy, Brennhausgasse 5, 09599 Freiberg, Germany; 2Saxon State Office for Environment, Agriculture and Geology (LfULG), Department of Geology (Saxon Geological Survey), Halsbrücker Straße 31a, 09599 Freiberg, Germany; 3German Center for Geosciences (GFZ), Telegrafenberg, 14473 Potsdam, Germany

The Mesozoic to Cenozoic intraplate to rift-related magmatic activity in central Europe spawned both, intrusive and extrusive carbonatites. Located within the intersection of the Regensburg-Leipzig and Gera-Jachýmov fault zones, the eroded diatreme of Ebersbrunn provides a unique opportunity for mineralogical and petrographic investigations to explore the magma genesis and its lithospheric evolution. Electron microprobe analyses on several mineral phases were acquired to obtain thermobarometric estimations and unravel the internal textures. Moreover, detailed microscopic studies on juvenile fragments are used for the characterization of volcanic facies. Here, the compositional variation in amphibole (with Mg# from 0.804 to 0.932) and mica (Al-rich phlogopite and eastonite) can be linked to the presence of lamproite components in the generation of supplying magma system and show a multi-episodic crystallization history. Thermometric estimations for the carbonatitic magma showed a wide range from 450 to 672°C (obtained on low- and high-Mg calcite and dolomite). The joint presence on high-T amphibole (872 to 965 °C) and mica ( ca. 950 °C) suggests the contemporaneous crystallization from a single magma storage and the presence of mid-crustal magma storage at 15 to 21 km.

The petrographical studies on circular/ ellipsoidal juvenile fragments revealed different populations of peletal lapillis, with either dry or wet silicate, Fe-Ti-oxide, and/or carbonate phases in the kernel and a carbonatitic and/or silicic shell composition. This indicates the influence of hybrid magma and emphasizes the multi-stage layering process. The oriented prolate-shaped apatite crystals at the rim of pelletal lapillies are addressed to turbulent motion during magma ascent.

Tue: 44
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Mineralogy and origin of a silico carbonatite mega xenolith in the alvikites of the Dicker Willem Complex (Namibia)

Lorenz Kemmler1, R. Johannes Giebel1,2, Benjamin F. Walter3

1Technische Universität Berlin, Ernst-Reuter-Platz 1, 10587 Berlin, Germany; 2University of the Free State, 250 Nelson-Mandela-Drive, Bloemfontein 9300, South Africa; 3Karlsruhe Institute of Technology (KIT), Institute for Applied Geosciences, Chair of Economic Geology and Geochemistry, Adenauerring 20b, 76131 Karlsruhe, Germany

The Eocene (49 Ma) Dicker Willem carbonatite complex represents an “Inselberg” (5 km2) forming a subvolcanic intrusion in southern Namibia. It consists of several stages of carbonatitic intrusions including, alvikite, sövite, nepheline sövite as well as carbonatite breccia. Associated silicate rocks (ijolite and nepheline syenite) are rare but found as xenoliths of various sizes embedded in carbonatite (sövite and alvikite). To decipher the genetic relation between carbonatites and silicate rocks and the formation of nepheline sövite (which is seen as a transitional lithology), we investigated a center-margin profile within a silicate-rich carbonatite xenolith (Ø 7 m) enclosed in fine-grained calcite-carbonatite (alvikite). Detailed observations show systematic mineralogical and mineral chemical variations depending on the contact proximity. Multiple element diffusions and transformation reactions can be traced. Mineralogically, feldspathoids are increasingly replaced by K-feldspar. Secondary biotite crystallized at the expense of feldspar and clinopyroxene close to the contact. Clinopyroxene compositions develop from a Ca (Mg, Fe) dominated to a Na (Fe) bearing variety. Excess iron (Fe3+) not being incorporated in biotite crystallized as hematite. With closer proximity to the host rock the dominant mineral within the xenolith becomes calcite (up to 95 modal%). These besides other indications suggest that a magmatic replacement of a silicate xenolith resulted in the successive transformation into a carbonatite, that is barely distinguishable from a coarse grained sövite. This process thus reflects the origin of the nepheline sövites rather than the liquid immiscibility that was thought to follow the genetic link between silicate rock and carbonatite at depth.

Tue: 45
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Global Sr-Nd-Os isotope compositions and highly siderophile elements of carbonatites

Ladislav Polák1,2, Tomáš Magna1, Lukáš Ackerman1,2, Vladislav Rapprich1

1Czech Geological Survey, Prague, Czech Republic; 2Czech Academy of Sciences, Czech Republic

The examination of more than 500 samples of worldwide carbonatites on the basis of Sr-Nd isotope systematics allows dividing them into three groups which do not follow conventional grouping. Carbonatites with a mantle signature and variable amounts of incorporated sedimentary material form the first two groups. The carbonatites in the third group have resolvedly lower 143Nd/144Nd signatures at a given eSr(i) value that cannot easily be explained by crustal contamination but rather by derivation of carbonatite parental melts from the mantle source metasomatized by 2-6% of slab-derived melts with low Sm/Nd during the late Archean (~2.7 Ga).

As a consequence of high concentrations of Sr and Nd, this system is more resilient to overprint compared to Re-Os elemental and isotope systematics. Overall, 44 carbonatite samples were investigated for Re–Os compositions; of these, 15 samples were excluded due to modification by late-stage hydrothermal alteration. The remaining carbonatites still yield a wide range of gOs from ~4 to 4000. Whether this wide range is a result of the presence of recycled crust or originates from previous carbonatite metasomatism remains unclear.

Extremely low concentrations of highly siderophile elements (HSE) in carbonatites and common nugget effects observed are the result of the behavior of sulfur-bearing phases as the main HSE carrier and oxygen fugacity. Carbonated silicate melts are capable to host significant amounts of PGE but during ascent, S-rich magma will separate from carbonatite melts leading to the sequestration of PGE due to higher distribution coefficients, leaving carbonatite melt depleted in PGE.

Tue: 46
Topics: 3.27 Alkaline rock and carbonatite related magmatism

Magmatic to hydrothermal REE mineralization in Mesoproterozoic ankerite carbonatite, Swartbooisdrift, NW Namibia

Albert Riehm, Kirsten Drüppel

Karlsruhe Institute of Technology (KIT), Germany

Strong local REE enrichment is observed in Mesoproterozoic ankerite carbonatite exposed at Swartbooisdrif, NW Namibia (Drüppel et al., 2005). The carbonatite dykes transect older anorthosites of the Kunene Complex and are themselves surrounded by sodalite-rich Na-metasomatic aureoles. The magmatic assemblage of ankerite, magnetite, pyrochlore, burbankite, and apatite indicates that the carbonatite magma was rich in Fe, Nb, P, Na, Sr, and LREE. Primary REE hosts are euhedral burbankite, pyrochlore, and apatite, which can be enriched in irregular layers formed during flow-banding.

Along cracks burbankite is altered to secondary burbankite and carbocernaite. With progressive alteration, burbankite and carbocernaite were partially to completely replaced by complex intergrowths of fluorcarbonates (mainly bastnaesite, hydroxylbastnaesite, parisite and synchysite), ancylite, monazite, barite, strontianite, celestine, calcite, fluorapatite, and/or hematite. Similar mineral assemblages also occur as discrete REE-rich pods and schlieren, suggesting fluid-related remobilization of REE and P. These zones are mainly restricted to the ankerite carbonatite, indicating locally restricted REE mobility.

The composition of early metasomatic and later hydrothermal fluids was determined by microthermometry and synchrotron-micro-XRF analysis of primary fluid inclusions in sodalite and secondary fluid inclusions in ankerite. Early high-temperature (> 550°C) sodalite-forming fluids were highly saline alkaline brines (19-30 wt% NaCl eq.) containing minor Sr, Ba, LREE, Nb, S, K, and Fe. Secondary fluid inclusions in ankerite, entrapped at lower temperatures of c. 400-500°C, are NaCl-poor (4-6 wt% NaCl eq.) and strongly enriched in Sr and REE. These fluids are presumably related to the late REE remobilization.

Drüppel et al. 2005, J. Petrol., 46, 377–406.

Tue: 47
Topics: 3.27 Alkaline rock and carbonatite related magmatism

The geochemical evolution of the Late Cretaceous intraplate volcanism on the Chatham Islands (NZ)

Johanna Schenk1, Stephan Homrighausen1, Hamish Campbell2, Kaj Hoernle1,3

1GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany; 2GNS Science, Lower Hutt, New Zealand; 3Institute of Geosciences, Kiel University, Kiel, Germany

The Chatham Islands, situated on the eastern Chatham Rise ~800 km east of New Zealand, comprise two main (Chatham and Pitt) and many smaller islands. Collision of the oceanic Hikurangi Plateau with the Chatham Rise jammed the long-lived subduction system, causing Zealandia to separate from Gondwana. The breakup was accompanied by volcanism on the South Island of New Zealand, Hikurangi Plateau (Hikurangi seamounts) and Chatham Rise and islands, many of which were formed by the volcanism. The Late Cretaceous volcanism is characterized by HIMU (high time-integrated μ=238U/204Pb Mantle) endmember composition, which sensu stricto is defined by oceanic islands associated to deep-rooted mantle plumes. Consequently, an heritage of the HIMU source from the lower mantle transferred to the surface by a mantle plume is debated, but numerous alternative models have been proposed to explain the HIMU volcanism in Zealandia, including sub-continental lithospheric mantle modified by subduction or interaction with the partly subducted Hikurangi plateau. Our major and trace element analyses of 52 Cretaceous whole-rock samples from the Chatham Islands display characteristic HIMU trace element compositions, but the major element (MgO vs. CaO) and olivine composition indicate a predominantly pyroxenitic (or phlogopitic) rather than peridotitic source, which is usually associated with HIMU lavas. Further investigation on the composition of primitive melts, melting conditions and source lithologies will be used to evaluate the potential role of a mantle plume causing HIMU end member volcanism and separation of Zealandia from Antarctica in the Late Cretaceous.

Tue: 48
Topics: 3.28 Developments and progress in regional geology

Triassic to Cretaceous magmatic record in SE Vietnam and southern Borneo: the southern limit of the Paleo-Pacific subduction

H. Tim Breitfeld1,2, Juliane Hennig-Breitfeld1,2

1Institute of Geology, TU Bergakademie Freiberg, Germany; 2SE Asia Research Group, Department of Earth Sciences, Royal Holloway University of London, UK

The eastern margin of Asia formed an active Andean-type margin from the Triassic until the Cretaceous. SE Vietnam and West Borneo were located at the southern end of this subduction zone. Triassic igneous rocks in Indochina are usually interpreted to be related to the closure of the Paleo-Tethys. However, in West Borneo Triassic I-type granitoids and associated fore-arc volcaniclastic turbidites can be attributed to west-directed subduction of the Paleo-Pacific. The arc can be traced through the South China Sea to SE Vietnam and Hainan with magmatism continuing into the Jurassic, although with a diminished intensity. Thus, West Borneo can be correlated with the Indochina basement. With the beginning of the Cretaceous and docking of the Banda block (which consists of SW Borneo) with West Borneo, large Paleo-Pacific subduction-related magmatic provinces formed in southern Borneo and SE Vietnam. Lower Cretaceous I-type granitoids are thereby dominant in Borneo, while in SE Vietnam Upper Cretaceous I-type rocks are more abundant. At around 80 to 85 Ma magmatism changed from I-type to A-/S-type affinities, suggesting cessation of the Paleo-Pacific subduction and a switch to post-orogenic magmatism that lasted until the end of the Cretaceous. The Mesozoic igneous record of the West Borneo and SE Vietnam provinces is remarkably similar and indicates a common tectonic history associated with the various stages of Paleo-Pacific subduction beneath eastern Asia.

Tue: 49
Topics: 3.28 Developments and progress in regional geology

The Muskau Arch - a geomorphological and geophysical approach on glacial tectonics

Sebastian Donke

Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg, Germany

The Muskau Arch (MA) is located in the border area of the federal states of Brandenburg and Saxony and Poland.

The Muskau Arch is part of the main Warthian terminal moraine in Germany. With its U-shaped form, it is the southernmost extension of the Warthe glaciation in Germany. The width reaches c. 20 km and the arc depth c. 22 km.

The morphology of the Muskau Arch is characterized by compression, folding and overthrusting of Tertiary strata. Including special features, such as a multitude of Gieser structures or folded Pleistocene channel deposits. The so-called Gieser (Wendish Jeser/ jezero: swamp) are terrain furrows with a maximum depth of 20 m, a width of 10 m to 30 m and a length of up to several kilometers. Thus they represent a characteristic geomorphological element. They were formed by weathering and oxidation of the tertiary lignite seams, which were folded by glacial deformations.

In addition to these structures, there are further glacial forms in the area of the Muskau Arch, which are partly visible in the morphology and partly can only be mapped as glacial structures by geological exploration.

In this Study glacitectonic structures (i.e. diapirs, rupture structures, folding and faulting) are analysed and reconstructed focussing on scales, depth range characteristic shapes. These structural geological investigations were based on geophysical methods (near-seismic, gravimetry, geoelectric soundings and mapping as well as borehole geophysical measurements).

Tue: 50
Topics: 3.28 Developments and progress in regional geology

Early Permian rhyolite volcanism and Jurassic alteration, Northern Schwarzwald, Germany - new evidence from geochemistry and U-Pb dating of zircon, monazite, uraninite, and xenotime

Kirsten Drüppel1, Emre Agca2, Armin Zeh1, Jens Grimmer1, Michael Waitzinger3

1KIT Karlsruhe, Germany; 2gbm, Ettlingen, Germany; 3Geological Survey of Austria, Wien, Austria

Formation of Early Permian rhyolites in the Schwarzwald postdates the exhumation of Variscan granites and gneisses. Although similar Permian volcanics are recognized across Central Europe, little is known so far about their source(s), precise ages, magmatic evolution, and later alteration. To answer these questions, we investigated 68 rhyolite samples (lavas, tuffs, ignimbrites, diatremes) from five different localities in the Northern Schwarzwald.

Most rhyolite samples contain phenocrysts of quartz, K-feldspar, and biotite set in a fine grained groundmass rich in secondary illite and hematite. Igneous zircon, monazite, Fe-Ti oxides, apatite, and uraninite are common accessories. All samples are peraluminous high-SiO2 rhyolites with calc-alkaline compositions. Mantle-normalized trace element patterns show negative Ba, Sr, Eu, and Ti anomalies, indicating plagioclase and Fe-Ti oxide fractionation. REE patterns with LREE enrichment and deep negative Eu anomalies characterize them as hot-dry-reduced rhyolites, typically occurring above areas of mantle upwelling. A likely source are lower crustal dry metasediments.

Secondary alteration is correlated with increases in Al2O3, LOI, Li, and As. At one locality, a unique secondary REE-P-As-Th-S assemblage, comprising monazite, gasparite, thorite, xenotime, and galenite, is observed. The As-REE-rich phases presumably originated from alteration of primary monazite, zircon, and apatite by As-rich aqueous fluids.

U-Pb La-ICP-MS dating of igneous zircon, monazite, and uraninite from different localities yields consistent crystallization ages of 296.0 ± 1.3, 297.5 ± 2.9 Ma, and 296.2 ± 1.1, respectively. A later Early Jurassic alteration event is evidenced by U-Pb ages of 181.5 ± 2.1 and 173.5 ± 1.6 Ma determined for secondary xenotime.

Tue: 51
Topics: 3.28 Developments and progress in regional geology

Geophysical signature of the early Carboniferous Saxothuringian Basin, Central European Variscides

Hamed Fazlikhani1, Uwe Kroner2, Harald Stollhofen1, Wolfgang Bauer1, Daniel Koehn1

1Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany; 2Institut für Geologie, TU Bergakademie Freiberg

The Early Carboniferous Saxothuringian Basin (SXB) is exposed on the northwestern side of the Bohemian Massif in Central Europe. SXB is bordered by the Mid-German Crystalline Zone (MGCZ) to the NW and N, by the Lausitz block and the Elbe Zone to the NE and E and the Tepla-Barrandian to the SE. Basin boundaries are defined based on the structural, metamorphic and stratigraphic observations of the exposed Variscan and pre-Variscan units in the Bohemian Massif. However, to the SW across the Franconian Fault System (FFS), Permian-Mesozoic sedimentary rocks cover the Variscan units including the possible SW extension of the SXB.

In this study we integrate geophysical (gravity, magnetic and seismic reflections) and well data to investigate the SW extension of the SXB and discuss implications for the Variscan tectonics. Our observations and forward modeling results show that the remnant of SXB extends about 60 km to the W-SW from the present-day FFS and terminates near the NE part of the Kraichgau Terrane. We also show that SXB units are most likely preserved below the Permo-Mesozoic units farther south, west of the Fichtelgebirge area. Based on our study, we discuss that the SXB developed as a low-strain and isolated area in the Saxothuringian Zone, receiving erosional material from the surrounding high-strain and uplifted areas during the Variscan tectonics in early Carboniferous, before being overfilled by the Middle Mississippian (Visean) time.

Tue: 52
Topics: 3.28 Developments and progress in regional geology

Early Jurassic K-Ar illite age data of fault gouge from a reverse fault of the Gernsbach-Neuenbürg flexure in crystalline basement rocks of the Nordschwarzwald (SW Germany)

Jens Carsten Grimmer1, Klaus Wemmer2, Mathias Hueck3, Jonas Kley4

1Karlsruhe Institute of Technology (KIT), Germany; 2University of Göttingen, Germany; 3University of Göttingen, Germany; 4University of Göttingen, Germany

We investigated a SSE-dipping reverse fault zone of the ENE-striking Gernsbach-Neuenbürg flexure within c. 325 Ma old coarse grained two-mica granite. The fault zone consists of a hematized, cataclastic 15-20 cm thick, damage zone, predominantly developed in the hanging wall, and a c. 1 cm thick greyish-greenish clay-rich fault core. We took two gouge samples, spaced c. 1 m apart from each other.

Both samples were fractionated into three grain sizes (<0.2 µm, <2 µm and 2-6 µm), all of which yielded ages between 198 Ma and 171 Ma. The fact that these ages are much younger than the age of the faulted host rock, and that both samples exhibit variations between the different fractions of a few tens of Myr at most, indicates efficient authigenic clay growth. This authigenic crystallization probably occurred between 200 °C and 300 °C, based on the illite “crystallinity” Index and the predominance of the 2M1 illite polytype in the samples.

The Gernsbach-Neuenbürg flexure plunges to the ENE beneath deformed Triassic strata of the ENE-striking, c. 100 km long „Neckar-Jagst-Furche“, which is yet kinematically poorly understood. Its large strike length and apparent low bulk displacements are consistent with reactivation of the southern boundary fault zone of the Permocarboniferous Kraichgau basin as suggested by mapping of the Gernsbach-Neuenbürg flexure. The widespread Jurassic radiometric age data in southern Germany indicate major hydrothermal activity and a structurally complex, yet poorly resolved, deformation pattern, most likely associated with oblique rifting that developed into formation of the North Penninic ocean.

Tue: 53
Topics: 3.28 Developments and progress in regional geology

On the nonexistence of a Saxo-Thuringian Ocean – a review

Uwe Kroner1, Rolf L. Romer2

1TU Bergakademie Freiberg, Germany; 2GFZ German Research Centre for Geosciences, Potsdam, Germany

As demonstrated by the Saxo-Thuringian Ocean, some regional geological models originated prior the advent of plate tectonics and evolved little since. Despite the abundance of facts that neither prove nor need the existence of such an ocean, this plate tectonic scenario is still widely used. The Saxo-Thuringian and Moldanubian zones represent classical areas of the Central European Variscides. The Saxo-Thuringian Zone originally was defined as a narrow marine basin with Paleozoic lithologies overlying a Precambrian basement. Early mobilistic models proposed an allochthonous origin of the Münchberg Massif, representing remnants of the Moldanubian Zone, thrusted onto a southeastern ramp of the autochthonous Saxo-Thuringian Basin. With the advent of plate tectonics, the Saxo-Thuringian Zone was reinterpreted as an independent microplate that is surrounded by oceanic lithosphere. In such a view, the subduction of a so-called Saxo-Thuringian Ocean beneath a Moldanubian microplate is necessary to transport Moldanubian crust onto the autochthonous Precambrian / Paleozoic units of the Saxo-Thuringian microplate. Over the last decades abundant new geoscientific data, including the results of the continental deep drill hole (KTB), challenged the Saxo-Thuringian Ocean hypothesis. Today there exist ample evidence (i) that the allochthonous units of the Saxon Granulite Massif and the Fichtelgebirge-Erzgebirge nappe pile experienced pervasive and prolonged Variscan tectono-metamorphic overprint and do not represent an older Precambrian ramp and (ii) that early Paleozoic Saxo-Thuringian marine lithologies were deposited on a vast contiguous Peri-Gondwana shelf. Incomplete recycling of extended continental crust during prolonged Gondwana Laurussia collision can explain the geological record of the Saxo-Thuringian Zone.

Tue: 54
Topics: 3.28 Developments and progress in regional geology

Upper Ediacaran carbonates on the Digermulen Peninsula, Finnmark, Arctic Norway: insights into syn- to post-depositional processes at the edge of Baltica

Guido Meinhold1, Sören Jensen2, Magne Høyberget3, Arzu Arslan1, Anette E. S. Högström4, Jan Ove R. Ebbestad5, Teodoro Palacios2, Heda Agić6, Wendy L. Taylor7

1TU Bergakademie Freiberg, Germany; 2Área de Paleontología, Universidad de Extremadura, Spain; 3Rennesveien 14, Mandal, Norway; 4Arctic University Museum of Norway, UiT – The Arctic University of Norway, Norway; 5Museum of Evolution, Uppsala University, Sweden; 6Department of Earth Science, Durham University, United Kingdom; 7Department of Geological Sciences, University of Cape Town, South Africa

The Digermulen Peninsula in eastern Finnmark has attracted renewed research interest in recent years due to discoveries of new Ediacara-type fossils, marking the rise of macroscopic life on Earth. The entire upper Ediacaran and Cambrian sedimentary succession was considered to be siliciclastic. However, carbonates were discovered within the 2nd cycle of the Manndrapselva Member of the Stáhpogieddi Formation of the Vestertana Group (Meinhold et al., 2019, Precambrian Research, 328, 99-110). These carbonates occur as calcareous siliciclastic beds, lenses, and concretions, some with calcite spherulites and cone-in-cone calcite, in a mudrock to fine-grained sandstone succession approximately 40 m below the Ediacaran–Cambrian boundary. The calcite spherulites were probably formed at the sediment–water interface or a few centimetres below, either in a coastal littoral environment or in situ in the sublittoral zone under high alkaline conditions. In situ calcite U−Pb isotope data from an upper Ediacaran carbonate concretion provide timing constraints for depositional, diagenetic, and potentially metamorphic processes, overlapping and confirming previous estimates based on relative bracketing of events (Meinhold et al., 2020, Geological Magazine, 157, 1367-1372). The cone-in-cone calcite formed during burial diagenesis and clearly before low-grade metamorphism and cleavage formation, the latter being caused by the Scandian Orogeny.

Tue: 55
Topics: 3.28 Developments and progress in regional geology

Nappe tectonics in the south-eastern Rhenish Massif (Central European Variscides, Germany) – Plate interactions between Gondwana and Laurussia

Katja Mende1, Ulf Linnemann1, Heinz-Dieter Nesbor2, Peter Königshof3, Ulrich Jansen3, Mandy Zieger-Hofmann1, Axel Gerdes4

1Senckenberg Naturhistorische Sammlungen Dresden, Germany; 2Hessisches Landesamt für Naturschutz, Umwelt und Geologie, Germany; 3Senckenberg Gesellschaft für Naturforschung Frankfurt, Germany; 4Goethe-Universität Frankfurt, Germany

The Lahn-Dill-Area, the Kellerwald and the Lindener Mark in the southeastern Rhenish Massif (Germany) are part of the Rhenohercynian Zone of the Central European Variscides. They contain various Devonian and Lower Carboniferous sandstones and greywackes, which differ significantly in their facies circumstances and fossil-content from surrounding autochthonous materials. U-Th-Pb- and Lu-Hf-analyses on detrital zircons of these allochthonous siliciclastic sediments indicate a provenance in the Saxothuringian zone and thus a Gondwanan hinterland. They show U-Pb-age clusters of ~530–700 Ma, ~1.8–2.2 Ga, ~2.5–2.7 Ga, and ~3.0–3.4 Ga. In contrast, samples from the autochthonous and par-autochthonous units of these areas show a provenance representative of Laurussia with debris primarily derived from Baltica and Avalonia with age clusters at ~400–450 Ma, 540–650 Ma, 1.0–1.2 Ga, ~1.4–1.5 Ga, ~1.7–2.2 Ga, and 2.3–2.9 Ga. These results, combined with own thin section analyses and geochemical data on volcanic rocks as well as revised biostratigraphy and paleobiogeography of Lower Devonian from the literature, led to the interpretation that the southeastern Rhenisch Massif is a nappe stack of Rhenohercynian and far transported Gondwana-related nappes. They were thrusted onto the autochthonous part of southern Laurussia during the Variscan orogeny by closing a wide Rheic Ocean.

Tue: 56
Topics: 3.28 Developments and progress in regional geology

Geophysics combined with Petrography – a promising approach for 3D crystalline basement characterization?

Christian Olaf Müller, Manuela Zeug, Alexander Malz

Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Germany

High-grade metamorphic and plutonic rocks in crystalline complexes are of increasing interest as host rock for geothermal plays and for understanding plate tectonics. In this regard the Pretzsch-Prettin Crystalline Complex (PPCC, Saxony-Anhalt) as a part of the Mid German Crystalline Rise is one prominent example of a late-orogenic intrusion in the former Rheic Suture Zone. Former 2D geophysical investigations focussing on the setting and outline of the PPCC remained ambiguous and suggested a combined interpretation with other geoscientific disciplines.

Recently, we applied a 3D geophysical and geological modelling to the PPCC incorporating well data, seismic depth maps and gravity data. 3D gravity modelling revealed important information on the general geological setting of the overburden and basement depth, but did not allow detailed interpretation in areas of similar basement density. Limiting the generally ambiguous gravity modelling results required incorporation of petrographic data like rock composition from thin sections and density measurements at rock samples, which were linked to the modelled density zones of the basement.

This approach revealed first evidence of a northward extension of the comparable low density monzogranites to granodiorites of the PPCC into the North German Basin. Quartz monzonites and monzodiorites with up to 25 % biotite and amphibole agree with up to 0.15 g/cm³ higher basement densities in the surrounding of the PPCC. Generally, incorporating petrographic data into the gravity modelling process enabled us to better confine zones of different crystalline compositions, which might be applicable to other areas.

Tue: 57
Topics: 3.28 Developments and progress in regional geology

Regional geology and structural control of copper-bearing vein formation in the Western Anti-Atlas of Morocco

Jasemin Ayse Ölmez1, Ida Maria Möckel1, Fatiha Askkour2, Moha Ikenne2, Atman Madi3, Christoph Hilgers1

1Structural Geology and Tectonics, Karlsruhe Institute of Technology, Germany; 2Faculté des Sciences, Université Ibn Zohr, Agadir, Morocco; 3Akka Gold Mining (Managem Group), Casablanca, Morocco

The Ouansimi copper mine is located south of the Kerdous inlier in the Western Anti-Atlas in Morocco. Neoproterozoic and Lower Cambrian sedimentary rocks record recurring transgressive and regression cycles by deposition of limestones, algae matts, or clastic rocks like conglomerates. The rocks are overprinted, likely due to the Variscan orogeny, resulting in an anticline formation showing internal large- and small-scale tectonic elements like folds, shearing, normal and reverse faults, as well as bend and drag folds.

The sedimentary rocks host mainly NW/SE striking veins with copper mineralisation, comprising e.g., chalcopyrite, chalcocite, sulfidic minerals, in combination with carbonates or quartz, as well as copper oxides (e.g., malachite) at the present-day surface. Processes, which lead to vein and ore formation and the possible tectonic influence are still not clearly understood. So far, the copper-bearing veins are mainly associated to the Variscan orogeny and hydrothermal influence. Field observations and structural measurements of stratigraphic bedding, fractures, and veins surrounding the Ouansimi mine are complemented with subsurface data, as well as transmitted and reflected light microscopy. Furthermore, microstructural observations are supplemented with cathodoluminescence microscopy.

This study will help to understand, if tectonic events beside the Variscan orogeny influenced the formation of veins and faults, as well as folds. Thus, the understanding of the regional geologic and tectonic processes of the Western Anti-Atlas region will be complemented.

Tue: 59
Topics: 3.28 Developments and progress in regional geology

The Late Paleozoic igneous suite between the Saxon granulite massif and the Altmark, central Germany: Petrogenetic and mineralogical constraints on the post-orogenic magma evolution

Alexander Repstock1, Manuela Zeug2, Elżbieta Słodczyk3, Hripsime Gevorgyan4, Michael Buchwitz5

1Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, Geological Survey and Geophysics, Pillnitzer Platz 3, D-01326 Dresden, Germany.; 2Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Department for Geology, An der Fliederwegkaserne 13, D-06130 Halle (Saale), Germany.; 3University of Wrocław, Institute of Geological Sciences, Ulica Cybulskiego 30, PL-50-205, Wrocław, Poland.; 4TU Bergakademie Freiberg, Institute for Mineralogy, Brennhausgasse 4, D-09596 Freiberg, Germany.; 5Museum für Naturkunde Magdeburg, Otto-von-Guericke Straße 68 -73, D-39104 Magdeburg, Germany.

The Late Paleozoic continental rift in the area of central Europe set the stage for intense magmatic activity, apparent in plutonic complexes (e.g. Brocken, Pretzsch-Prettin), large subvolcanic bodies (e.g. Halle laccoliths, Wurzen porphyries), and recorded by voluminous pyroclastic sheets in numerous caldera systems (e.g. Wurzen, Rochlitz, and Flechtingen ignimbrites). Since up to now, their petrogenetic evolution often remains veiled in mystery or is still under debate. Focussing on this post-Variscan magmatic flare-up, the obtained geochemical and mineralogical data set depicts selected magma reservoirs, their evolution, and storage.

The different compositions of the Cadomian to Variscan basement and the longevity of magma chambers set within these particular regions have a decisive influence on the geochemical characteristic. In detail, metasedimentary rocks (e.g. metamorphosed graywacke, mica schist) are most often directly responsible for Al2O3-supply and subsequently lead to corundum-normative magmas. The highest amount of normative corundum (up to 3.1 wt%) can be found in the Flechtingen ignimbrite, which magma system was capable of crystallizing almandine garnet (Ca0.03Fe0.84Mg0.13)3Al2Si3O12) in lower crustal levels (>7 kbar ≙ 25 km). A similar picture emerges within the subordinated diopside-normative parts of the Wurzen volcanic rocks (up to 3.28 wt%), where crystallization of calcic clinopyroxene took place at 6 to 10 kbar (≙ 22 to 36 km). Here, it is proposed that parental diopside normative alkaline to tholeiitic and garnet-bearing magmas are fast ascending and mingled into upper crustal magma bodies.

Tue: 60
Topics: 3.28 Developments and progress in regional geology

The tectonics of the Elbtalschiefergebirge-Osterzgebirge-Zone and the role of the Mid-Saxon-Fault

Lea Marie Schulze1, Uwe Kroner1, Ines Görz2

1TU Bergakademie Freiberg, Germany; 2Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, Germany

The Elbe zone constitutes a complex fault zone on the northern edge of the Bohemian Massif. As part of this zone, the Elbtalschiefergebirge is juxtaposed with the Lausitz to the northeast and the Osterzgebirge to the southwest. The tectonic boundary with the Osterzgebirge is traditionally defined by the Mid-Saxon-Fault. In the course of a tunnel project for the railroad line Dresden-Prague structural geological investigations were carried out. Here first results are presented. The entire area was overprinted by the Variscan orogeny and can be divided into three principal units. (i) The northeastern section consists of very low-grade metamorphic lithologies representing the remnants of an early Carboniferous synorogenic basin. The adjoining unit (ii) is predominantly made up by phyllites that differs from unit (i) by its stronger tectonic and metamorphic overprint and partly inverted stratigraphy. Mylonites on both sides of the Mid-Saxon-Fault reveal the existence of a ductile shear zone (iii) affecting high- to medium-grade metamorphic units of the Osterzgebirge as well as low-grade units of the Elbtalschiefergebirge. This Elbe-zone parallel, i.e., NW-SE striking shear zone suite is characterized by dextral strike slip tectonics and the transition from ductile to brittle-ductile material behavior. The existence of ESE-WNW to E-W stretching lineations on both sides of the Mid-Saxon-Fault , however, indicates a more complex tectonic evolution. Furthermore, the mylonites adjacent to the “Tourmaline-granite” of the Elbtalschiefergebirge resemble the shear zone rocks of the Erzgebirge. Thus, the traditional view of the Mid-Saxon-Fault as a strict tectonic boundary between both units must be questioned.

Tue: 61
Topics: 3.28 Developments and progress in regional geology

Distribution of Holstein interglacial deposits in Brandenburg and Berlin (Germany)

Jaqueline Strahl, Sophia Rütters, Angela Sonntag

Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg (LBGR), Germany

The Holstein interglacial is classified as the period between the end of the Elster glaciation to the beginning of the Fuhne glaciation. The deposits in Brandenburg are supplied by limnic to fluviatile sedimentary regimes. Thus, the deposits consist of organic mud and silt as well as bituminous peat. Related to higher energetic levels, the fluvial associated deposits are made up of sand. The stratigraphic classification is based on palynostratigraphy and on the occurrence of the index fossil Viviparus diluvianus.

In this study, a new map is constructed that focuses on the distribution of limnetic sediments. Contrary to this, the existing maps summarise the limnetic and fluviatile deposits including the sediments of the lower Saale. Two sets of maps have been published since 1971 (Lithofazieskarte Quartär - scale 1:50 000 and Zwirner & Ziermann 2010 - scale 1:1 000 000).

Based on more than 400 palynostratigraphically proven locations (via drillings), a map will be published that achieves a significant extension and clarification of the distribution of the limnetic Holstein. The accumulation area of these deposits can be associated with numerous channel systems and paleo-basins initiated during the Elster glaciation. Furthermore, transgressive pathways are revised in this study. These were derived from Holstein Stage sea-level changes that resulted in transgressive and regressive successions with brackish to marine facies in northwest Brandenburg.

Zwirner & Ziermann 2010. „Verbreitung und Tiefenlage der Holstein-Warmzeit und frühsaalezeitlicher Ablagerungen“ in Stackebrandt, W. (Hrsg.). Atlas zur Geologie von Brandenburg. Landesamt für Bergbau, Geologie und Rohstoffe Brandenburg, 53.

Tue: 62
Topics: 3.28 Developments and progress in regional geology

Changes in palynofacies and organic geochemistry as indicator for marine ingressions in the German Wealden

Fritz-Lukas Stoepke1, Annette E. Götz2, Martin Blumenberg3, Julia Gravendyck4, Jochen Erbacher3, Roberto Pierau2, Robert Schöner2, Ulrich Heimhofer1

1Leibniz University Hannover, Germany; 2State Authority for Mining, Energy and Geology, Germany; 3Federal Institute for Geosciences and Natural Resources, Germany; 4Rheinische Friedrich-Wilhelms University Bonn, Germany

New palynological and geochemical data from the KB Rehburg-2 core covering the German Wealden (W1-4) illustrate the unique development of this depositional setting. Despite the temporary isolation of the Lower Saxony Basin (LSB) from the open ocean, several marine flooding events into the basin were detected. Marine ingressions are suggested to have entered from the west via the East Netherlands High, supporting the existence of an - at least temporary - seaway to the Boreal Realm. In the central and eastern parts of the LSB, indicators of marine influence are less prominent. In this study, we use a combined approach including palynofacies analysis, sedimentological and geochemical data in order to improve the understanding of the highly variable German Wealden depositional environment. The new data provides evidence for marine ingressions into the isolated LSB, insights into vegetation dynamics and palaeoenvironmental conditions.

A total of five different types of palynofacies were distinguished, which indicate changes in the oxygenation state of the water column as well as variations in salinity. Based on changes in continent-derived particle abundance, the proximity to the Deister-Hils Delta can be estimated. The most proximal palynofacies type stems from palaeosols, which are described for the first time in the German Wealden. Marine ingressions were identified using ecological preferences of aquatic palynomorphs (dinoflagellates, acritarchs, prasinophytes, Botryococcus) across the studied sedimentary sequence. Based on changes in palynofacies and geochemical proxies, ingressions already postulated in other studies were identified and a new, previously unknown ingression is observed.

Tue: 63
Topics: 3.28 Developments and progress in regional geology

Precise Timing of Permian-Carboniferous magmatism in Saxothuringia

Marion Tichomirowa, Alexandra Käßner

TU Bergakademie Freiberg, Germany

Here we present published and new age data of plutonic and volcanic rocks from Saxothuringia obtained by the high-precision CA-ID-TIMS U-Pb zircon dating method. This method has an uncertainty of ca. 0.1-0.2 % (corresponding to < ± 0.5 Ma) that is ca. 10 times smaller than all other recently established dating methods. Consequently, the application of this method allows better establish the exact sequence of magmatic processes in time and space. We show that magmatism in the Erzgebirge and in the Lausitz mainly occurred during two larger magmatic phases and that volcanic rocks first appeared in the Eastern Erzgebirge. We present also dating results from several volcano-sedimentary basins in Saxothuringia that allows a better comparison of their temporal evolution.

Tue: 64
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Problems with geothermal probes in evaporite deposits in Saxony-Anhalt

Christoph Gauert1,2, Jörg Steinborn1

1Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Germany; 2University of the Free State, South Africa

Near-surface geothermal energy as a key technology for the sustainable provision of heating and cooling is increasingly coming into focus as renewable energy and alternative to fossil fuels. In Saxony-Anhalt with an estimated 6,000 geothermal systems operational, several hundreds are being installed annually, incresasingly also in public and commercial buildings.

Areas, where water-soluble rocks carry the risk of karstification and sinkhole occurrence, are clustered in places of the Zechstein outcrop on the Harz Mountain rim, on the contours of the Halle Permo-Carboniferous complex and the Flechtinger Höhenzug. Near-surface Upper Buntsandstein, Middle Muschelkalk and Gipskeuper karstable rocks occur in the Weferlingen-Schönebecker Scholle, in the Hakel, Huy, Fallstein, the Oschersleben-Egelner salt axis, and in the Subherzyn.

Karst areas often contain particularly concrete-aggressive waters, so that special measures must be taken to protect geothermal probes. In addition, in the often cavernous or fissured rock, mud losses are to be expected, or the proper backfilling of the borehole is problematic. Further aspects can be the reduced thermal conductivity.

There is a risk of volume increase due to the transformation of anhydrite into gypsum after contact with water, which can lead to uplift of the terrain above evaporite lithologies. Building ground hazards can occur in the area of salt mining and near-surface salt deposits.

Permitting practice shows that for site-specific projects in the karst areas of Saxony-Anhalt sensu lato, heat recovery from the ground via geothermal collectors is recommended in order to avoid scoring, dissolution and hydration of the rock at risk of subrosion.

Tue: 65
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Das Geologische Landesamt Hamburg – Ein Zustandsbericht im Jahr 2023

Alf Grube, Susanne Aarburg, Kai Damerau, Christina Götz, Thomas Haupt, Jens Kröger, Lothar Moosmann, Udo Quek, Ingolf Stüven

Geologisches Landesamt Hamburg, Germany

Das Geologische Landesamt Hamburg wird in diesem Jahr 75 Jahre alt. Die Tätigkeiten der Vorläuferinstitutionen reichen über 100 Jahre zurück. Die heutige Kernaufgabe des GLAHH ist nach GeolDG die Sammlung, Digitalisierung, Interpretation und Veröffentlichung von geowissenschaftlichen Daten. Inzwischen sind ca. 315.000 Bohrungen bis in eine Tiefe von mehr als 3.000 m digital erfasst und zum Großteil veröffentlicht. Das Bohrdatenportal des GLA-HH bietet zusätzlich zahlreiche Kartendarstellungen zu geologischen, geothermischen und hydrogeologischen Themenbereichen, z.B. die Geologische Karte 1:5.000, Präquartär-Karten, ca. 65 Profilschnitte bis in ca. 400 m Tiefe, Wärmleitfähigkeit und Temperaturen für verschiedene Teufenbereiche und hydrogeologische Profiltypen. Ein wichtiger, und von Dritten intensiv angefragter Arbeitsbereich des GLAHH ist die 3D-Modellierung. Während das tiefe 3D-Strukturmodell gemeinsam von den norddeutschen Ländern entwickelt wurde, wird in Hamburg ein „mitteltiefes Modell“ mit Schwerpunkt auf den wasserwirtschaftlich genutzten Bereichen von Quartären und Neogenen Einheiten bis in ca. 400 m Teufe dargestellt. Das dritte Hamburger Modell stellt das Quartär dar, differenziert in Grundwasserleiter und -nichtleiter, wobei bei letzteren Tills und Beckenablagerungen unterschieden werden. Auf Grundlage der gewonnen Erkenntnisse aus Landesaufnahme und der 3D-Strukturmodellierung werden auch wasserwirtschaftliche Grundwasserströmungsmodelle aufgebaut, um aktuelle Fragen der Trinkwasserversorgung im Ballungsraum Hamburg zu beantworten. Zukunftsthemen, wie eine erfolgreiche Umsetzung der Wärmewende mithilfe der oberflächennahen, mitteltiefen und tiefen Geothermie nehmen einen immer größer werdenden Raum ein und werden von den Bürgerinnen und Bürgern sowie von Unternehmen in Hamburg stark nachgefragt. Die Arbeiten zu Geogefahren umfassen die Themenbereiche Verkarstung (Erdfallbildung; Mikroseismik), Massenverlagerungen (Rutschungen am Elbhang) und Bauwerksschäden durch wasserempfindliche Böden (u.a. Sackungen über austrocknendem Lauenburger Ton).

Tue: 66
Topics: 4.08 Geological surveying as services for the public delivered by the State Geological Surveys of Germany - Current Issues

Updating the depth map of the base Quaternary in Saxony-Anhalt

Simon Jagemann1, Christian Olaf Müller2

1Martin Luther University of Halle-Wittenberg, Germany; 2Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Germany

Continuously growing demands for exploitation and storage in the near subsurface require up to date information on the setting of the unconsolidated Cenozoic rocks. Of special relevance are depth information on the base Quaternary for mapping Pleistocene tunnel valleys to answer hydrogeological questions and for preparing 3D subsurface models. Current studies in Saxony-Anhalt still incorporate the results of the map series “Lithofazieskarte Quartär” (LKQ), which was prepared between 1968 to 1984. However, newly available evidence from digitized seismic depth maps and drilling results suggest an update of the depth information of the base Quaternary in Saxony-Anhalt.

In a first step, wells penetrating the Quaternary were exported from the well database of Saxony-Anhalt and their stratigraphies were simplified. Relevant wells were subsequently selected by unambiguous stratigraphy, similarity of well elevation with DGM height, cross validation and comparison to the well database of the LKQ. The remaining 85.000 relevant wells were combined with newly stratified wells and digitized isobaths of the base Quaternary from seismic data and former studies to a new base map. Subsequent quality control comprised tests of different gridding algorithms and profile drawing.

The new depth map of the base Quaternary reveals updated pathways of Pleistocene tunnel valleys of up to 500 m thickness in the Altmark region and in Eastern Saxony-Anhalt. Here, changes to the LKQ are largest. Minor differences are observed in the western and southern parts of Saxony-Anhalt with thicknesses usually less than 50 m.

Tue: 67
Topics: 4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment

Publication and Accessibility of Structural 3D Models of Saxony-Anhalt

Tilman J. Jeske, Melanie Siegburg, Alexander Malz, Manuela Zeug, Christian Olaf Müller, Jacob Wächter, Lars Schimpf, Ivo Rappsilber

Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Halle (Saale), Germany

The publication and accessibility of geological data is one of the main tasks of geological surveys. Provided data helps to understand the local geology, facilitates exploration of natural resources and thus benefits state services, businesses, and the public alike. The State Geological Survey of Saxony-Anhalt (LAGB) uses its database from decades of geological exploration to provide information of the subsurface geology. Past interpretations existed but provided only simple presentations of the three-dimensional space. More recently, huge datasets were used for the development of largely enhanced 3D models. So far, regional 3D models have been prepared for the deep subsurface comprising the Altmark region in the north, the Subhercynian Basin in the middle, and the South-Eastern Harz Foreland in the south of Saxony-Anhalt. These models are based on existing maps from subsurface exploration, seismic profiles, and borehole information. ArcGIS and SKUA-GOCAD were used as data management and modelling tools. Some challenges consist of low data density in some regions, contradictory or incorrect source data, as well as in achieving a coherent 3D model by smooth integration of modelled layers from different authors. The resulting three-dimensional geological models of Saxony-Anhalt illustrate the structural setting and the geology of the Earth's subsurface and will become subsequently filled with further lithological and petrophysical parameters. To publish the models for a broader audience, we use the GST (Geosciences in Space and Time) framework. This toolkit eventually enables the creation of customized sections, virtual borehole profiles, and the export of parts of the models.

Tue: 69
Topics: 4.09 3D models in education and outreach - synergy of research, geotourism, conservation and georisk assessment

Geological Mobile Digital Mapping (GeoMoDiM)

Pascal Michael Woiton, Mario Valdivia Manchego, Benjamin Kipp

University of Bonn, Germany

Geological mapping represents an important qualification within the framework of geoscientific programmes of study. The GeoMoDiM project, funded by Bonn University, aims to firmly integrate digitally supported geological mapping into the curriculum. In particular, the tablet- and cloud-based data collection in the field is to be prepared, carried out and evaluated with GIS support. This approach saves numerous work steps and avoids sources of error, allowing live communication and data exchange in the field.

This new procedure is already in practice, involving the students in the optimizing and streamlining process. Here we show that using tablets with QField the process of mapping can be improved through the ability of gathering all the data in one application compatible with the current workflow of QGIS, saving time and simplifying use. On top we integrate photogrammetry in the didactics, incorporating 3D models of outcrops into the subsequent analysis.

A second aim of this digital approach is to integrate students, who cannot participate in the fieldwork, into the process through video communication and live data exchange with partners in the field. Controlling of the fieldwork can be done online from a base station, evaluating, exchanging datasets and interpretative approaches with the participants in the field. Additionally, we focus on participants with disabilities, who are unable to join the field experience, they will benefit from this new didactic approach. The next step of this project is to open this new perspective to other research areas as botany and soil sciences.

Tue: 70
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?


Dulce Manuel Lima1, Nir Orion2, Clara Maria Vasconcelos1,3

1Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; 2Department of Science Teaching, Weizmann Institute of Science, Israel; 3Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; Unit of Science Teaching and Department of Geosciences, Environment and Land Planning, Faculty of Sciences, University of Porto, Portugal

Promoting quality education implies that teachers are reflective professionals, agents of innovation and change leaders, able to train students with critical thinking skills, problem-solving, creativity, collaborative work, and communication. In this conscious reflection, it becomes fundamental to shift the focus from teaching to learning, including the teacher himself, leading to developing new skills and attitudes, given the imperative of change. Thus, it is essential to establish teachers' continuous training relevant to initial training, which enhances their professional performance and, consequently, educational improvement. However, the pedagogical practices implemented in training must reflect congruent teaching with what is recommended as desirable in the professional version of future teachers, making the articulation between theory and practice a practical reality. In this action-research process, a pedagogical intervention programme was implemented in the course unit Didactics of Geology II of the master’s degree in biology and geology, according to an inquiry-based methodology focused on the active participation of the students and collaborative work among peers. With a holistic view of the Earth system for understanding the geological phenomena and processes, practical work was done. The laboratory and experimental geosciences activities were adapted from Orion’ previous work and contextualised according to the Portuguese Curriculum of the K7 grade. It was possible to collect evidence showing that pre-service teachers were encouraged to change their visions about how (geo)science can be learned and taught. Results reveal that the practical activities promoted (geo)science reasoning, meaningful learning, and professional development.

Tue: 71
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?


Dulce Manuel Lima1, Nir Orion2, Clara Maria Vasconcelos1,3

1Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; 2Department of Science Teaching, Weizmann Institute of Science, Israel; 3Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; Unit of Science Teaching and Department of Geosciences, Environment and Land Planning, Faculty of Sciences, University of Porto, Portugal

The concern with teaching centred on the characteristics and students’ needs is one of the reasons why the Multiple Intelligence (MI) theory is emerging and has become a trend in educational settings at the elementary, secondary, and higher education levels. Especial literature considers that intelligence is no longer restricted to cognitive talents but rather the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. These characteristics are based on eight types of intelligence Musical, Linguistic, Logical-Mathematical, Spatial, Bodily-Kinesthetic, Interpersonal, Intrapersonal and Naturalist intelligence. Exploring students' learning styles through their MI type allows teachers to identify their strengths and weaknesses and explore these styles in teaching methodologies. Additionally, teachers must understand students’ learning styles and MI to define activities that fit the different bits of intelligence by promoting better educational environment processes. In a pedagogical intervention program implemented in classes of the curricular unit of Didactics of Geology II (that integrates the curriculum of a master to train students to become biology and geology teachers), activities were carried out to teach and consolidate knowledge about Rock Cycle. After the intervention program, students presented the Rock Cycle in accordance with their style of learning. A content analysis was done on twenty-one “snapshot reports” done by the pre-service teachers. As in several studies that refer to the success of using the MI in the teaching process, our study gathered evidence of students' increased motivation to learn and a more active engagement.

Tue: 72
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?


Dulce Manuel Lima1, Isabel Maria Teixeira1, Sofía Riaño2, Clara Maria Vasconcelos1,3

1Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; 2KU Leuven, Department of Chemistry, B-3001 Leuven, Belgium; 3Interdisciplinary Center of Marine and Environmental Research (CIIMAR), Portugal; Unit of Science Teaching and Department of Geosciences, Environment and Land Planning, Faculty of Sciences, University of Porto, Portugal

The Science/Technology/Society perspective in promoting scientific literacy in metal recycling becomes fundamental for adopting good behaviours in our society that contribute to the independence of Europe on critical raw materials and, therefore, to the transition to greener technologies and circular economies. In this regard, researchers must develop recycling routes, manufacturers must design for recycling, and our society needs to become aware and educated about recycling and responsible consumerism. Teaching Natural Sciences to pupils from middle school is an opportunity to awaken and strengthen the student's curiosity about the world around them. Through an appealing and dynamic discussion exercise, the student’s learning process can be promoted by motivating them to understand the importance and impact of scientific problems, relating them to social issues and technological innovations in their daily life. The research reveals that storytelling is an enjoyable, meaningful, effective, and creative way to enhance teaching and promote learning. As a powerful education multidisciplinary strategy, storytelling should be promoted in Geoscience teaching, encouraging environmental sustainability behaviours and students' civic education. The created storytelling "Gil broke his mobile phone! Now what?" is a playful-sensorial animation for K7 students whose setting is a Natural Science class. Faced with the challenge “How can I contribute to sustainable development when my cell phone is no longer useful?” the plot appeals to students' awareness of behaviour change towards sustainable development. At the same time, it also addresses the issue of bullying in the school context.

Tue: 73
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

UmweltNAVI Niedersachsen - an app for the presentation of geospatial data not only from the environmental sector.

Joachim Müller

wemove digital solutions GmbH, Germany

Governmental and scientific institutions often have a problem communicating their data treasure to people outside their community. Presenting geospatial data in an appealing and accessible way is a challenge, especially when non-scientific people are the target audience. The app "UmweltNAVI Niedersachsen" sets out to do just that and demonstrates it using institutional environmental data. A person can discover the data in the immediate vicinity or in other locations. The data can be displayed either as polygons or as map layers (e.g. geotopes, noise and radiation pollution, flood areas, occurrence of wolf and lynx). When opening a dataset, the person receives various detailed information combined from different sources, like Wikipedia or
The app was designed for a broad user community of education, interested individuals or experts. Easy navigation, understandable operation and various functions that invite to discover are here to appeal to people of all ages. A knowledge area deepens the topics and allows dedicated viewing of individual datasets. Other functions, such as "geo-caching" of datasets, a quiz or the possibility to upload own photos to the data, are intended to motivate people to engage with the topics.
The project was initiated by the Lower Saxony Ministry for the Environment, Energy and Climate Protection/Germany and was implemented together with the companies Bearingpoint and wemove digital solutions. The principle of presenting geodata can also be applied to other areas. The software is basically available for subsequent use.
The poster shows essential aspects of the app and intends to arouse interest.

Tue: 75
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

GEOWiki@LMU – an update

Donjá Aßbichler1, Carolin Otte1, Daniel Schmid1, Elina Bauer1, Natalie Diesner1, Leonard von Ehr1, Paul Herwegh1, Philipp Kessler1, Leon Koß1, Phil Lavorel1, Alina Piller1, Andrea Schmid2, Wolfgang Stoiber1, Malte Junge3, Eileen Eckmeier4

1Ludwig-Maximilians-Universität München, Germany; 2Technische Universität München, Germany; 3Mineralogical State Collection (SNSB-MSM), Germany; 4Christian-Albrechts-Universität zu Kiel, Germany

GEOWiki@LMU is a constantly growing open platform for the promotion of practical and research-oriented knowledge acquisition. Its major objective is to provide information on methodologies relevant to geosciences, with focus on fieldwork, sample preparation and analytical methods. It offers students a quick overview including helpful practical tips and references to relevant literature. In addition, there are various new developments which are presented here:

OPEN-VHB: The GEOWiki@LMU team developed the course “Geosphere” on the platform of the “Virtuelle Hochschule Bayerns – VHB” to provide non-geoscientists an introduction into geoscience. Interactive tools are used to show how determination of minerals and rocks works, it also gives a short introduction in earth history or applied geology.

Moodle: This concept will be expanded to create a moodle based training-platform to provide interactive exercises not only for students but also for pupils and interested people.

The most fascinating aspect of GEOWiki@LMU is that it is elaborated by students of earth sciences. The contents are developed by students in courses or on their own initiative in interdisciplinary teams. The activity of the students is essential for the development of GEOWiki. It gives decisive impulses for the selection and structure of the topics, writing the articles and acquisition of funding. All topics are discussed in weekly editorial online-meetings and revised in close collaboration with lecturers and scientists. All graphics, icons and videos are created by the students. The website is also programmed by students, according to the motto: what doesn't fit is made to fit.

Tue: 76
Topics: 4.10 Geoscience Education Research - What do we Know About Learning and Teaching geosciences?

From planetary sciences, earth sciences, volcanology to robotics and agriculture: Highlights from the 7th Summer School on Vulcano, Sicily, 2023

Vikram Unnithan1, Frank Sohl2, Christian Riedel3

1Jacobs University Bremen, Germany; 2DLR; 3University of Potsdam

The annual Summer School on Vulcano, Sicily will take place at the end of June 2023. This poster gives an impression and an overview of the highlights of this successful field-activity based summer school. This two-week summer school, is being held for the 7th time, and provides an important training ground for students, scientists, researchers, and technicians by exposing them to a variety of disciplines from geology, volcanology, geophysics, astrobiology, to planetary sciences. This year's additional theme is going to be robotics and agriculture - how our advances in robotics, especially from the space sciences, can aid and support agriculture and food production. In addition to lectures, a number of scientific experiments are planned on Vulcano, such as geoelectrics, astrobiology, spectroscopy, robotics, and intelligent drone-based mapping for agriculture. The summer school participants get the opportunity to work in teams on the above topics and are involved in the data acquisition, processing, visualization, and presentation. Lunchtime lectures, evening social events such as poster sessions, astronomy, and GIS classes complement the field-based activities. The interaction and collaboration between researchers is encouraged to foster inter- and transdisciplinary learning and understanding.
In addition to institutional funding, the summer school would not have been possible without generous funding by the Helmholtz iFOODis project and EUROPLANET.

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