In the last decade, lithium has become a European strategic metal due to its extensive consumption in electromobility and green technologies. Consequently, global demand has increased substantially encouraging European interest in assessing its own resources, identifying a potential Li-industry and securing its own supply. In this context, a geographically-based compilation of the European lithium from both: 1) hard-rock, and 2) deep fluids occurrences and ore deposits, with their corresponding features (e.g., deposit types, Li-bearing minerals, Li content, host-rocks) have been assessed.

Accordingly, it appears that lithium is not particularly rare and is relatively well represented and distributed within Europe. Indeed, regarding lithium hard-rock resources, about 527 occurrences including 30 deposits have been identified mostly related to endogenous processes such as lithium-cesium-tantalum (LCT) pegmatites, rare-metal granites and greisen mineralization. Wheareas, about 182 occurrences of Li-bearing geothermal fluids from which Li content is above 15 mg/l has also been identified.

It appears that Li is significantly enriched in two distinct geodynamical contexts: 1) late orogenic process, related to a continent-continent collision for endogenous processes; and 2) local crustal thickening, as well as post-orogenic extensional setting for the exogenous processes. Thus, the complementarity of these two studies has been demonstrated that Li-bearing geothermal brines are coeval with emplacement of Li-magmatic bodies (LCT pegmatites and granites) as well as emplacement of large sedimentary basins in Europe suggesting an extensional setting as observed for Li-rock hard-rock deposits.

As a leading industrial country, Germany has a great need for metallic raw materials, which will even increase over the next years with the intended energy and mobility transition.

To meet the demand for metallic raw materials, the industry in Germany is heavily dependent on imports from abroad. To reduce this dependency on imports, Germany is working towards a circular economy in which resource efficiency and the recycling of metals play a prominent role. However, a circular economy will only be able to cover a portion of the necessary raw material requirements. Therefore, the import of primary raw materials will continue to be of decisive importance in the future.

The sourcing of the raw materials, however, must be responsible in order to avoid human rights violations and environmental impacts in the metals supply chains.

Human right violations can nowadays be managed quite well in metals supply chains through laws and guidelines. But so far there are no adequate instruments to address environmental risks in metals supply chains. Despite this lack of instruments, the EU is considering to enact a supply chain regulation which could make manufacturers liable for environmental impacts in countries where the metals are produced.

To facilitate the assessment of environmental risks in metals supply chains, a hands-on screening tool to recognize and red flag environmental risks in such supply chains using the example of battery metals is presented.

Since metals are often used in alloyed forms, proper management and efficient recycling of metal scrap is key to sustainable management of those alloying metals as well. Previous studies on the trade of metals and metal containing products focused mainly on the carrying major metals themselves, however, the quantity and type of their embodied alloying elements remain rarely investigated. In this paper, we aim to address this knowledge gap by compiling an alloying element composition database for scrap of three bulk metals (iron and steel, aluminum, and copper), and using Denmark, a typical industrialized country with a high share of metal scrap export, as an example. Our results show that most alloying elements embodied in bulk metal scrap exported from Denmark depict a fluctuating yet overall increasing pattern from 1988 to 2017. Denmark’s metal scrap exported almost only to European countries, and Germany and Sweden are two largest receivers. While alloying elements embodied in steel scrap such as chromium and nickel and the construction sector contribute the most to the total embodied alloying elements, other alloying elements such as cobalt, bismuth, vanadium, titanium, and niobium with a lower amount yet a high market value and criticality status deserve a closer look as well. We conclude that further investigation on how the trade of metal scrap affect the recycling pathways and efficiencies of alloying elements are needed to support discussion on global and regional resource management and circular economy strategies.

To reach Germany’s climate neutrality goal in 2045, different technological and systematical changes have to be conducted, such as the expansion of renewable energies plants, the shift towards e-mobility and the necessary infrastructure. For the measures, metallic raw materials will be increasingly required. The German government plans to support those industry sectors, which are emitting great amounts of CO₂. The data evaluation on emissions and energy consumption in Germany shows that the sector "production and first processing of iron and steel" is the second largest emitter of CO₂ in Germany, with around 40 million tons of CO₂ per year. On the one hand, steel is essential for the construction of renewable energy plants and, on the other hand, its production accounts for appr. 5 % of total German CO₂ emissions. Consequently, steel production is part of the solution and the challenge of the climate neutrality goal. Various options to decrease industrial CO₂ emissions in Germany are being discussed, as e.g. the use of hydrogen. To produce green hydrogen, various metallic raw materials are required for the production of green energy plants and electrolyzers. The amount of the metallic raw materials is calculated specifically for the application of hydrogen in the German steel production in 2030.

The underground storage will play an important role in the energy transition, both for energy storage as for CCS. Current storage activities in the Netherlands are for natural gas, diesel oil and nitrogen are in both in depleted gas reservoirs and salt caverns. These probably will be extended in the near future with storage of CO₂, hydrogen and compressed air.

The Dutch State Supervision of Mines is the regulator who oversees that these activities are performed in such a way that they are safe, now and in the future. This means that the full life cycle has to be considered with a broad perspective on the safety of people and the environment.

The predictions of behaviour of the storage and its fluids and related risk will have large uncertainties due to the level of uncertainty in the subsurface data used, and the limited amount of data to calibrate the models which calculate the risk. In most cases this will mean that the risk can’t be calculated probabilistically. In that case for decision making it is necessary to not only investigate the most likely scenario, but to the range of realistic, possible scenarios to identify the real risk. The period after storage will be orders magnitudes longer than the storage activity itself. This will lead to even larger uncertainties for this phase.

We have to face the fact that we can only partly reduce this uncertainty by further research and monitoring. However research and monitoring can help us to quantify the uncertainty. This emphasizes the importance that operators, policy makers and regulators are able to handle the uncertainties in their decisions before, during and after the storage activities, and communicate openly about them.

Re-using of large-volume salt caverns for the intermediate storage of liquid and gaseous energy carriers is an indispensable step on the way to a sustainable energy economy. Continuous development of methods for monitoring these facilities is a crucial part of the social license to operate. In the research project "Monitoring system for the safety of cavern storage facilities using satellite and unmanned aerial system (UAS) data" (KaMonSys), safety solutions for critical infrastructures are implemented in an interdisciplinary approach of remote sensing and geoscientific methods. Using underground storage facilities (USF) as an example, multisensory approaches are being developed to monitor the facilities as well as their surroundings by satellite and UAS-based monitoring to detect possible emissions, such as methane, hydrogen and carbon dioxide.

The coupling of classical geological methods of subsurface assessment with innovative approaches from remote sensing shows a huge potential for further research. Although KaMonSys will initially be developed for a cavern storage facility, which have considerable relevance for the "in time" gas supply of Germany, the final process will also be applicable to other industries as a safety solution for secondary markets.

This presentation describes the initial evaluation of available spatial data (INSPIRE and associated project partners Uniper and Salzgewinnungsgesellschaft Westfalen) on the surface/Subsurface situation, the integrated development of a 3D geoinformation system (GIS) to evaluate data and its usage for the development of 3D UAS flight plans.

The project is supported by federal funds within the German BMBF funding framework "Research for Civil Security" (FKZ 13N15366).

The transition from nuclear and fossil energy to renewable energy leads to higher fluctuations in energy supply – but storage for power is negligible so far. In underground gas storages (UGS) huge amounts of TWh can be stored to meet the demand consistently. However, this results in increasing injection and extraction frequencies, leading to faster pressure and stress changes and therefore posing additional challenges for reservoir rock, cap rock and technical components.

To evaluate the effects of additional cyclic loading on the rock-cement-steel-compound of the UGS infrastructure, we use an autoclave system on a realistic scale. Mainly abandoned drillings are simulated, the system therefore consists of a 2 m long cemented steel casing with an autoclave chamber at each end and surrounding heating mats. To simulate injection and extraction, gas pressure (N₂) is applied and released on both ends. Additionally, temperature can be raised to 100 °C. Between loading cycles, permeability can be measured to determine the effect of pressure and temperature variation on the tightness of the system.

We present results from the analysis of three cemented casings. Since the hardened cement isn’t connected to the steel casing after experiments, we assume an annular gap as main gas path. This gap is modelled and fitted to the experimental data. After pressure variations between 0 bar and 60 bar, tightness of the system decreased in every experiment, which leads to an increased modelled annular gap width. Temperature variations between 30 °C and 70 °C tend to increased tightness slightly.

Untertage-Gasspeicherung stellt eine wesentliche Nutzung des Untergrunds dar. Sie trägt insbesondere zur Stabilität der Energieversorgung bei. Auch in Zukunft kommt der geologischen Kurz- und Langzeitspeicherung stofflicher Energieträger eine große Rolle zu.

Obwohl die Gasspeicherung in Salzkavernen Stand der Technik ist, haben sich die Betreiberanforderungen dahin gehend geändert, dass neben den saisonalen Gasumschlägen zunehmend auch kurzfristige hoch-frequente Speicherzyklen aufgrund veränderter Speichermarktanforderungen gefahren werden. Insbesondere aufgrund der thermo-mechanischen Wechselwirkung beim Ein- und Ausspeichern von Gas resultieren daraus grundlegend neue Fragen zur Betriebssicherheit, d. h. Integrität der geologischen Barriere Salz sowie der technischen Installation des Bohrloch-Casings im Kontakt mit der Bohrlochzementierung sowie dem Salzgebirge.

Unter der Zielstellung einer qualifizierten Bewertung potentieller Risiken bei den verschiedenen Varianten des modernen Speicherbetriebes wurde durch das IfG im Rahmen des BMBF-Forschungsvorhabens SUBI eine umfassende Studie zu den verschiedenen Aspekten durchgeführt.

Ausgehend von einer umfassenden Literaturstudie zum nationalen und internationalen Stand der Fluidspeicherung in Kavernen in Salzgesteinen wurden die aktuellen technischen Konzepte dargestellt und stattgefundene technische Havarien ausgewertet. Die daraus resultierende Arbeitsthese ist, dass bei den in der Literatur beschriebenen Havarien kein integrales Versagen der Salzbarriere stattfand, sondern generell technische (z.B. schlechte Zementation) oder geologisch/geomechanische Bohrloch-Casing-Probleme (z.B. Strukturrandlage, ungünstige Salzbedingungen, Überlagerungen im komplexen Kavernenfeld) ursächlich waren.

Zur Verifizierung dieser Thesen wurden sowohl experimentelle Untersuchungen an natürlichen Salzgroßproben und Bohrlochzement als auch modelltechnische Arbeiten zur Modellierung von zyklisch überprägten saisonalen Belastungen bei der Gasspeicherung in Salzkavernen durchgeführt.

The assessment of the long-term stability of geological units in the context of subsurface use is a complex topic in which various geoscientific and technical aspects play an important role. For example, the geomechanical stability of radioactive waste repositories due to endogenous, exogenous and engineering processes is an important aspect in the long term. For a stability prognosis, an estimation of the recent stress state as well as an assessment of realistic future stress changes is required. However, data on the current stress state in the upper crust are incomplete, sparse and spatially unevenly distributed. Therefore, geomechanical-numerical models are the only possibility to estimate the complete stress tensor at locations where stress observations are not available.

The SpannEnD project, had the goal to estimate the 3-D stress state in Germany. Therefore, a simplified subsurface model was created. Since stress data are essential for the calibration procedure, the first open access database for stress orientations as well as stress magnitudes was developed, which mainly summarises data from the study region. The best-fit stress model is assigned to the model which reproduces the results of many of the available magnitudes of horizontal stresses well. In the model region, there are numerous large-scale faults or fault systems that have an influence on the local stress state. However, the large number of faults could not be implemented as structural features in the geomechanical model. However, the modelled stresses are applied on the fault geometries to assess the fault reactivation potential.

The overall amount of metals and their variety used for technical applications has been subject to a steep increase during the past decades and is forecast to further develop. Growing metal demand for a wide range of high technology applications, including so-called ‘green’ technologies (e.g. PGM, REEs, Te) drives the economic value of these metals and the related mining efforts. For some of these metals, anthropogenic metal fluxes have outcompeted natural biogeochemical cycles, including plate tectonics (Sen & Peucker-Ehrenbrink, 2012). Dispersion and loss, inherent to their cycle between production and use (e.g. PGM from automobile catalytic converters), limit their overall recycling rates and/or end-of-life recovery is uncertain as collection and recycling still need development (e.g. REE, Yang et al. 2017). Their presence in all environmental compartments, including remote areas, makes these metals emerging contaminants and warrants systematic surveillance. However, the geochemical backgrounds, often at ultra-trace levels, and anthropogenic contributions of the critical elements are still widely under-documented, as many analytical challenges persist. Studying exposure and effects in complex environmental matrices, including natural waters or biota, at environmentally relevant contamination levels, is a prerequisite to the assessment of exposure risks.

References

Sen, I.S., Peucker-Ehrenbrink, B., 2012. Anthropogenic disturbance of element cycles at the Earth’s surface. Environ. Sci. Technol. 46, 8601–8609. https://doi.org/10.1021/es301261x

Yang, Y., Walton, A., Sheridan, R. et al. REE Recovery from End-of-Life NdFeB Permanent Magnet Scrap: A Critical Review. J. Sustain. Metall. 3, 122–149 (2017). https://doi.org/10.1007/s40831-016-0090-4

Siderophores are important biogenic chelators produced by plants, microbes and fungi, which promote the (bio-)availability of iron and other highly-charged cations in the natural environment. The hydroxamate siderophore desferrioxamine B (DFO-B) enhances the mobilization of certain trace elements that hydrolyze easily and hence are traditionally assumed as being ‘immobile’ during water-rock interaction. Leaching of different rock material with DFO-B under ambient conditions, for example, facilitates the formation of a very pronounced positive Ce anomaly in bulk-normalized patterns and fractionates the Th-U element pair, which we tentatively attributed to an oxidation of Ce(III) to Ce(IV) and U(IV) to U(VI). We here reports results of an investigation into the effects of solution pH, fO₂ and weathering state of different rocks on the mobilization of redox-sensitive trace elements and their isotopes during water-rock interaction in presence of DFO-B. The impact of natural organic ligands on redox-sensitive elements may be largely underestimated. Siderophores are omnipresent today and may also have been present in the geological past. Our preliminary results indicate that the impact of solution pH on fractionation of redox-sensitive trace elements is rather small, but that fractionation is strongly controlled by oxygen fugacity and by the weathering state of the studied rock. Siderophores have the potential to significantly catalyze the oxidation of these elements even under strongly hypoxic conditions.

Rare Earths and Yttrium (REY) have become pivotal constituents of many high-technology products and processes. Their widespread use has led to a growing release of (“anthropogenic”) REY into the environment and hence rising concerns about their (bio)geochemical and (eco)toxicological behaviour. Yet, information on REY transfer, fractionation and bioaccumulation and -magnification in the food web is still scant.

Here, we present REY data for naturally grown duckweeds and ambient waters. Duckweeds are small, rapidly-growing macrophytes inhabiting many lentic water bodies worldwide. Duckweed is increasingly used as protein-rich animal feed and food supplement for vegans. The REY concentrations of duckweeds are in the µg/kg range (dry matter) and exceed those of ambient waters by several orders of magnitude, revealing strong bioaccumulation. Their shale-normalised (_SN) REY patterns are rather flat and show little variation regardless of sampling site and season. By contrast, the REY_SN patterns of all 0.2 µm-filtered water samples are characterised by an increase from light REY (LREY) to heavy REY (HREY) and some show large anthropogenic positive Gd_SN anomalies. Such anomalies have become common in Germany and can be attributed to the application of Gd-based contrast agents (Gd-CAs) in magnetic resonance imaging. The absence of anomalous Gd enrichment in all duckweed samples suggests that Gd-CAs are not incorporated by these macrophytes but corroborates their conservative behaviour in the environment. Moreover, partition coefficients between duckweeds and ambient waters show that the duckweeds preferentially incorporate LREY over HREY, possibly due to stronger complexation of HREY with dissolved ligands.

Rare Earths and Yttrium (REY) are widely used in many domains, resulting in anthropogenic input into the environment. However, still little is known about their uptake and bioavailability towards aquatic organisms.

We studied REY bioavailability by quantifying their concentrations in the aragonitic shells of Corbicula fluminea, which are precipitated from the extrapallial fluid (EPF) of the mussel. Both shells and ambient water samples were collected from the Elbe and Weser rivers which are known to carry anthropogenic gadolinium (Gd) from Gd-based contrast agents (Gd-CAs) applied in magnetic resonance imaging. The shells were grouped according to their size, meticulously cleaned, acid-digested and pre-concentrated before ICP-MS measurement. Analytical quality was monitored by using REY-poor reference material JLs-1.

Total REY concentrations in the shells decrease with increasing shell size, indicating that REY uptake occurred most rapidly during the juvenile age of mussels. Shale-normalized REY patterns show a continuous increase from light REY (LREY) to heavy REY (HREY) and a slightly inverse V-shape for shells from the Elbe and Weser rivers, respectively. Compared with the 0.2 µm-filtered waters from the same locations, the shells show between 2 to 4 magnitudes higher total REY concentrations. Despite significant anthropogenic Gd enrichment in the river waters, no Gd anomaly is observed in the shells suggesting long environmental half-life and poor bioavailability of the Gd-CAs. Partition coefficients between shells and water reveal a preferential uptake of LREY over HREY in mussel shells. These observations complement and corroborate the results of previous research on shells from the Rhine River.

Uranium (U) isotopes are suggested to monitor the success of (bio)remediation relying on the reduction of soluble and mobile U(VI) to less soluble U(IV)¹. However, the subsurface stability of U(IV), typically present as solid-phase non-crystalline U, may be affected by complexation or oxidation. Understanding these processes and their impact on U isotope fractionation is important to correctly interpret field U isotope signatures.

We investigated U mobilization by complexation and oxidation and measured the associated U isotope fractionation in laboratory batch experiments. Non-crystalline U(IV) was produced as the starting material by reducing a U(VI) isotope standard with Shewanella oneidensis MR-1². Subsequently, U(IV) was mobilized: 1) anoxically, with ligands (EDTA, citrate, or bicarbonate), 2) by oxidation with Fe(III), or 3) with molecular oxygen at low pH in the presence of the bacterium Acidithiobacillus ferrooxidans.

All ligands mobilized U(IV) and enriched ²³⁸U in the complexed fraction (δ²³⁸U: 0.2 to 0.6 ‰). Oxidative U mobilization both, with Fe(III) or with At. ferrooxidans biomass, resulted in insignificant U isotope fractionation. Either isotope fractionation during all involved reaction steps was very small or cancelled eachother out. The latter may be indicated by the observation of high aqueous δ²³⁸U values (~0.8 ‰) in corresponding abiotic control experiments (without biomass), which may be the result of adsorption effects after oxidative U mobilization.

(1) Bopp et. al. Environ. Sci. Technol. 2010, 44 (15), 5927–5933.

(2) Stylo et al. Environ. Sci. Technol. 2013, 47 (21), 12351–12358.

The Icelandic mantle plume is probably the largest convective upwelling on Earth. It is generally agreed that its growth and evolution have had a significant influence on the geologic and oceanographic evolution of both the North Atlantic Ocean and Northwest Europe during Cenozoic times. At the present day, three significant observations testify to the existence and size of this plume.

First, residual depth anomalies prevail in the oceanic lithosphere surrounding Iceland. These anomalies show that the oceanic plates are 1-2 km shallower than expected in a region that stretches from Baffin Bay to the coast of Norway, and from Svalbard to Newfoundland.

Secondly, an irregular-shaped long wavelength free-air gravity anomaly with an amplitude of 30-50 mGal is centred upon Iceland.

Thirdly, full-waveform tomographic imaging of the North Atlantic region shows that the planform of the Icelandic plume has a complex irregular shape with significant shear wave velocity anomalies lying beneath the lithospheric plates at a depth of 100-200 km. Distribution of these anomalies suggests that about five horizontal fingers extend radially beneath the fringing continental margins. The best-imaged fingers lie beneath the British Isles and beneath western Norway where significant departures from crustal isostatic equilibrium have been measured. It has been suggested that these radial fingers are generated by a phenomenon known as the Saffman-Taylor instability. Experimental and theoretical analyses show that fingering occurs when a less viscous fluid is injected into a more viscous fluid. For radial, miscible fingering, the wavelength and number of fingers are controlled by the mobility ratio (i.e. the ratio of viscosities), by the Péclet number (i.e. the ratio of advective and diffusive transport rates), and by the thickness of the horizontal layer into which fluid is injected. Shear wave velocity estimates have been combined with residual depth measurements around the Atlantic margins to estimate the planform distribution of temperature and viscosity within a horizontal asthenospheric layer beneath the lithospheric plates. These calculations yield mobility ratios, Péclet numbers, and asthenospheric channel thicknesses that are compatible with Saffman-Taylor fingering. A useful rule of thumb is that the wavelength of fingering is ~5 times the thickness of the horizontal layer. Across the Northwest European shelf, the pattern of mapped residual topography and subsidence anomalies is remarkably consistent with the planform of asthenospheric fingering. In conclusion, a combination of disparate observations supports the notion that Cenozoic dynamic topography of Northwest Europe is generated by fast, irregular horizontal flow within thin, but rapidly evolving, asthenospheric fingers of the Icelandic plume.

Widespread exhumation and uplift affected Central Europe in Late Cretaceous to Paleogene time (e.g. Kley and Voigt, 2008, Geology, 36, 839-842). The area involved includes thrust-related basement uplifts and inverted Mesozoic basins and extends at least from the Rhenish Massif to the Bohemian Massif and from the Black Forest/Vosges to the North German Basin. Exhumation and basin inversion started at approx. 95 Ma based on stratigraphic constraints (Voigt et al. 2021, Solid Earth, https://se.copernicus.org/preprints/se-2020-188), well in line with ZHe cooling data (e.g. von Eynatten et al. 2019, International Journal of Earth Sciences, 108, 2097-2111). Late Cretaceous SW-NE directed basement thrusting (e.g. Harz Mountains, Thuringian Forest, Flechtingen High) peaked around 85 to 70 Ma. Thermochronological data (AFT, AHe) from the Triassic uplands between the basement highs reveal km-scale exhumation of a wider region, at least 250-300 km across, suggesting long-wavelength domal uplift (von Eynatten et al. 2021, Solid Earth, 12, 935-958). This domal uplift is dated slightly later at 75 to 55 Ma and calls for a separate mechanism superimposed on the Late Cretaceous compressional event. Based on timing, spatial extent of the doming area and thickness of eroded strata (3-4 km), possible mechanisms are evaluated for their contribution to exhumation and uplift. While shortening and crustal thickening may explain 50% of the domal uplift at most, upwelling asthenosphere driving dynamic topography appears capable of producing uplift and erosion of the required magnitude, wavelength and rate.

East European Craton (EEC) in Poland has been recently studied by onshore PolandSPAN and offshore BalTec regional seismic surveys. PolandSPAN data imaged earliest Late Jurassic, earliest Late Cretaceous and mid-Late Cretaceous laterally extensive unconformities that document hitherto unknown substantial uplifts of the SW edge of the EEC. Cretaceous unconformities might have been formed as a result of inversion-induced buckling of the cratonic edge. BalTec offshore survey was acquired within the transition zone between the Paleozoic Platform and EEC. SW part of BalTec data imaged offshore segment of the Mid-Polish Swell formed due to inversion of the axial part of the Polish Basin. NE from the MPS, within the Bornholm–Darłowo Fault Zone, system of Late Cretaceous strike-slip syn-depositional faults was documented. E part of the BalTec survey is located above the EEC basement overlain by Cambro-Silurian sedimentary cover that is dissected by a system of steep, mostly reverse faults, regarded so far as having been formed as a result of the Caledonian orogeny. BalTec seismic data proved that at least some of these deeply-rooted faults were active as a reverse faults in latest Cretaceous. This suggests that large Paleozoic blocks might have been uplifted during the widespread Late Cretaceous inversion. Erosion of these blocks might have provided sediments that formed Upper Cretaceous progradational wedges within the onshore Baltic Basin imaged by PolandSPAN data.

This study was funded by NCN grants UMO-2017/27/B/ST10/02316 and UMO-2015/17/B/ST10/03411. ION Geophysical is thanked for providing PolandSPAN seismic data, and Kingdom IHS for providing seismic interpretation software.

The Phanerozoic lithosphere in Central Europe was formed due to the Caledonian and Variscan Orogenies. It then probably underwent modification and thinning associated with widespread and intense Permian volcanism. Since the Permian, the evolution of the Central Europe lithosphere is characterized by various phases of moderate extension and inversion tectonics caused by external forces. Sedimentation and intra-plate volcanism yield evidence for additional intra-plate processes related to variable lithsopheric thickness and deformation. Whereas its crustal structure has been extensively studied by Deep Seismic Soundings, properties of the subcontinental mantle lithosphere including its thickness are less well known. Surface waves are well suited to study the lithosphere and the sub-lithospheric structure, being mainly sensitive to the S-wave velocity structure at those depths. Here we present results of high-resolution surface-wave tomography, down to ~250 km depth, from automated broad-band inter-station Rayleigh phase velocities. The thickness of Central Europe lithosphere shows a remarkable variability. Thick lithosphere is found beneath the Paris Basin, whereas the lithosphere in the area of the North German Basin and the Bohemian Massive shows moderate thickness. Thinner lithosphere is found in the area of the Cenozoic intra-plate volcanism. Comparison to the distribution of Permian and Jurassic volcanic rocks provides evidence for a time variable thickness of the continental lithosphere in Central Europe. We relate subsidence and sedimentation without substantial extension to lithospheric cooling and thickening. In contrast, uplift and volcanism without compression indicate thermal thinning of the lithosphere. Conceptual models for the lithopsheric evolution in the area are discussed.

Coastal regions represent a transition between land and sea. From the hydro(geo)logical point of view freshwater and saltwater are coming together here. The groundwater discharge which discharges directly into the sea is called submarine groundwater discharge (SGD). At the regional scale, SGD is often measured indirectly based on tracers. At the local scale, SGD flux over time can be measured directly, e.g. using seepage meters. However, this method only represents the punctual source of discharge. Especially to record the diffusive discharge locations, a new method which focuses on the puddles in intertidal areas as potential diffusive discharge locations was developed. There, the salinity and water depth were observed at different puddle locations over time. Moreover, photos were taken in order to get information about the changing area of the puddle. From these data we calculated a water budget to show how much submarine groundwater discharges at the measured puddle. The results show a geographically and temporal variability of the SGD in the mudflat of the south of Königshafen on Sylt. The diffusive discharge locations were primarily located at the beginning of the intertidal zone. In order to support the new method, two additional pore water measurements were conducted at each puddle. The salinity of the pore waters were freshening with increasing depth here. The presented method can help to transfer the observed data of SGD to a regional scale.

Detailed process-understanding of climatic and non-climatic drivers is generally required to estimate future groundwater availability under climate change. Groundwater level (GWL) dynamics are very sensitive to groundwater pumping, but information on their local effects and magnitude – especially in combination with natural fluctuations – is often missing or inaccurate. It has been shown by previous studies that complex hydrogeological processes can be learned from neural networks, whereby Deep Learning (DL) demonstrates its strengths particularly in combination with large data sets. However, there are limitations in the interpretability of the predictions and the transferability with such methods. Furthermore, most groundwater data are not yet ready for data-driven applications. This study aims at improving GWL predictions with DL by combining big data elements from a newly constructed global groundwater database with long-term short-term memory (LSTM) networks. Our underlying hypothesis is that scale-dependent processes can be learned for groundwater dynamics, similar to streamflow data. For our experiments we use continuous groundwater level observations from basins worldwide and basin attributes – spatially heterogeneous but temporally static catchment attributes (e.g. topography) and continuous observations of the meteorological forcing (precipitation and temperature). The initial results are consistent with previous studies in that GWL prediction performance is good with LSTM models trained with climate input on single wells. It is now being tested whether the LSTM model trained on many wells simultaneously is able to represent the climatic effects - but not the anthropogenic effects, e.g. with wells that are considered to be anthropogenically unaffected.

Saline contaminants from potash mining endanger aquatic ecosystems. Uncovered potash tailings piles release high amounts of chloride and sodium. Conventional coverage systems with a transpiration-intensive vegetation on a soil layer reduce percolation water only to some extent and does not protect the surrounding environment sufficiently. Powerful sealing layers are used to cover other mining deposits, but are still uncommon for potash tailings piles. In this paper, I study how to complement conventional coverage with additional sealings to minimize the release of contaminants effectively. I investigate a yet uncovered potash tailings pile in Germany. I model water balance parameters and calculate percolation rates for 44 different coverage systems. The results show that sealings always outperforms (max. 24.8 % of P) conventional coverage without an additional sealing (26.5 % of P). Site-specific coverage reduces percolation water more than uniform coverage and requires less layer material. A sealing works best on slopes with a northern orientation, soil cover systems perform better on southern slopes. I conclude that site-specific coverage systems are most effective to improve water quality in post-mining landscapes.

With the recently announced climate neutrality for the year 2060, there are plenty of questions in China about the future and the existence of the hard coal mining industry. With an annual production of 4 billion tons of hard coal, China remains the biggest producer of this resource. The consequences for the environment are tremendous. Climate neutrality poses new challenges for this country with its abundance of resources: hard coal is still the easiest and safest way to guarantee the supply of energy to its citizens, whereby energy security is a high priority. The switch to and the integration of renewable energies has already started and, according to the latest 14th five-year plan, should become the main driver of growth in the coming years. The transition to green development with a low carbon economy as one of the most important objectives is imminent. These developments will have a decisive impact on the next few years and will drive structural change forward. Since China also has large reserves of rare earths, which are required in particular for the construction of regenerative energy options. But here, too, only one environmental problem is shifted to the next, since the recycling of rare earths has not yet been developed and the sustainability factor is a big question mark. What impact this will have in terms of sustainability and environmental protection is identified in the research project.

The Enguri Dam in NW Georgia is one of the highest arch dams in the world. The 15 km power tunnel was initially flooded in 1978. During the rehabilitation project from January - April 2021, an 40 m long open construction-joint was observed. The construction-joints are located on both sides in the lower third of the tunnel, but only the construction-joint on the valley side showed an opening character.

The research question of the paper was whether the preferential opening of this joint can be explained by rock stresses.

The approach is based on the comparison of a numerical calculation of the stress-state with the observed cracks (recorded in April 2021) in the tunnel section at km 13.7, using a static, linear elastic 2D model with homogeneous material (limestone) with a variable FE-mesh. The initial stress-state is created via a lateral shortening at the valley side of the model in combination with gravitation.

The results show a symmetrical distribution of tensile and compressive stresses around the power tunnel, with the axis of symmetry tilted by about 30°. This results in tangential tensile stresses on the downslope side in the region of the construction-joint, while compressive stresses are expected in the section of the upslope construction-joint.

It has been shown that the initial stress-state is an important parameter for the positioning and design of the power tunnel. Furthermore, the topography can result in tilting of the stress field, which must be considered in the interpretation of observed fractures in the tunnel.

Smectites are widely used in (geo-) technical applications and are important components of soils. A definition gap exists between the uncharged non-swellable pyrophyllite and talc (ξ = 0) and the low charged swellable clay minerals (smectites) with 0.2 ≤ ξ ≤ 0.6. Furthermore, no reliable measurement method exists for ξ < 0.2. A recent theoretical study on the hydration of smectites (Emmerich et al. 2018) based on the density functional theory (DFT) indicates the existence of stable dioctahedral 2:1 layer silicates with ξ < 0.2 and substitutions either in the tetrahedral or octahedral sheet that are swellable. Therefore, our focus is to synthesize low charged smectites.

The Na₂O-MgO-Al₂O₃-SiO₂-H₂O system was reacted for triocthedral smectite synthesis at 200℃, for 72 h, and with stoichiometric composition corresponding to ideal layer charge of 0.18. The XRD results showed that the synthesis of trioctahedral smectite was successful with a small particle size. Particle size will be confirmed by AFM measurements. The CEC indicates a low charge in the envisaged range. According to the principle of AAM method (Lagaly. 1981), under ideal assumptions, when the layer charge value is less than 0.2, the long-chain alkylammonium ions will only form a monolayer structure (basal spacing <17.7 Å) after being intercalated into the smectite layer, which can also be proved by measuring the d001 value of synthetic smectite. Similar results obtained through our experiments.

References:

Emmerich et al. (2018) The Journal of Physical Chemistry C 122, 7484−7493.

Lagaly. (1981) Clay Minerals. 16, 1-21.

In the end of 2020, an approx. 650 m deep core was drilled at Prees in Shropshire, England, as part of the ICDP project JET (Integrated Understanding of the Early Jurassic Earth System and Timescale). The main objective of this project is to obtain and characterize a complete and continuous sedimentary archive of the 25 million years of the Early Jurassic. The Early Jurassic period (200-175 million years) was a period of extreme environmental changes: Rapid transitions from cold or ice ages to super-greenhouse events have been documented, including global changes in sea level and organic carbon distribution, as well as mass extinctions.

Knowledge of this part of the Earth's history is supposed to serve as an analogue for present and future environmental changes. The project will provide a "master record" for an integrated stratigraphy (bio-, cyclo-, chemo- and magnetostratigraphy) of this period. In addition, the project will allow the reconstruction of the local and global palaeoenvironment and the driving mechanisms and feedbacks responsible for environmental changes in the Early Jurassic.

The analysis of geophysical borehole measurements contributes to interpretations with respect to the lithological characterization of sediments and their boundaries, but also allows the description of sedimentary cycles related to orbital parameters, insolation and therefore to paleoclimatic history.

First results of these borehole measurements include a lithological classification which is based on cluster analysis of solely physical data. Furthermore, core-log integration has been carried out and a first attempt towards astrochronology and cyclostratigraphy has been made.

Understanding the evolution of lower latitude climate from the most recent glacial periods to post-glacial warmth in the continental tropical regions has been obstructed by a lack of continuous geological records. Here we present results from a lacustrine record from tropical North America. Specifically, we examine sediments from Lake Chalco, located in the Valley of Mexico, central Mexico (19°30’N, 99°W). The basin represents a hydrological closed system surrounded by the Trans-Mexican Volcanic Belt aging from the Oligocene to the present. We used borehole logging data to conduct a cyclostratigraphic analysis of the Lake Chalco sediments. More than 400 m were logged for several geophysical properties including magnetic susceptibility and spectral gamma radiation (SGR).

SGR is a particularly useful tool as it is non-destructive, fast, affordable, and applicable even in cased boreholes. Among the lake deposit of the Chalco sub-basin, 388 total tephra layers (≥1 mm in thickness) were reported from the core description. Tephra layers with specific gamma-ray signatures present a challenge for extracting the primary signals caused by climatic agents. We propose a protocol to identify tephra layers embedded in other sediments using high-resolution SGR.

After extracting the non-volcanic primary signal, we applied a suite of evolutive cyclostratigraphic methods to the Lake Chalco downhole logging data, with a focus on gamma-ray. The high-resolution gamma-ray results suggest that the Lake Chalco sediments contain several rhythmic cycles with a quasi-cyclic pattern comparable with Pleistocene climate evolution, allowing to calculate of a ~500-kyr time span for the Lake Chalco sediment deposition.

The new hydraulic coring system Hipercorig was developed to recover undisturbed long cores from deep lacustrine sediment archives that record past environmental conditions and changes (Harms et al., 2020). Here we report initial results from the deep lake drilling project ‘Hipercorig Hallstatt History’, which succeeded to recover two 41m and 51m long cores and to conduct downhole logging in spring 2021 with the Hipercorig System on Lake Hallstatt. This inner-alpine lake, characterized by very high clastic sedimentation rates, is located in the heart of the UNESCO World Heritage region Hallstatt - Dachstein – Salzkammergut, whose early history of Stone Age settlement and salt mining is still not yet fully understood. Also, there is a lack of reliable observational data on past environmental and climatic conditions, and frequencies and impacts of meteorological and geological extreme events of that time, that are needed to holistically understand past environmental-human-environmental interactions. The new >50 m long sediment cores from Lake Hallstatt now overcomes the previous coring-depth limit (16 m subsurface, dated to ~2.3 cal ka BP) and covers a presumably continuous sedimentary succession throughout the Holocene and Late Pleistocene since the retreat of the Traun glacier. Here we present first results from the Hipercorig coring and logging campaign, along with initial results from whole-round core analyses (Multi-Sensor-Core-Logging; and X-ray Computed Tomography) and preliminary Core-Log-Seismic-Integration, revealing unprecedented scientific samples and data, that will provide unique insights into the early development of one of the oldest cultural landscapes in the world.

A 6-meter drill core from Merensky Reef, Bushveld Complex, South Africa, was scanned in detail with a drill core scanner based on Laser Induced Breakdown Spectroscopy. The purpose of the investigation was to visualize variations in the chemical composition along the core, and following a mineral classification of the LIBS data, of variations in the mineral chemical composition as well.

The LIBS technology is based on atomic emission spectroscopy, in which the excitation of the atomic species occurs in-situ on the sample surface. The excitation source was a pulsed 50 mJ 1064 nm Nd:YAG laser, and the emitted light was collected with a high-resolution wide-range echelle spectrograph with CCD detector. For validation purposes, selected samples were analysed with bulk chemical analysis and electron probe microanalysis as well.

Distinct trends could indeed be extracted from the 6 m core section through the Merensky Reef. From a saw-cut core surface without further preparation, a continuous record could be extracted consisting of bulk chemical patterns, modal composition, and direct neighbourhood. The data can be used to highlight the presence of unusual patterns and to relate them to Ni, Cu, PGE or other mineralization. When applied to different core sections, it may become an important tool for comparing lateral variability of diagnostic horizons in vertical sequences in layered intrusions such as Merensky Reef and UG-2.

A key aim of the ICDP Oman Drilling Project is to constrain magmatic processes beneath fast-spreading mid-ocean ridges. Several drill cores from the Samail ophiolite (Oman), which is regarded as the best-preserved piece of ancient oceanic lithosphere on land, were obtained. Drill core GT1 covers about 400 m from the layered gabbro section between ~1200 and 800 m above the mantle transition zone (maM). The vast majority of the samples recovered are (olivine-) gabbros with a few cm-scale layers of anorthosite, troctolite, and wehrlite. We found a large scale fractionation trend from 800 to 1070 maM in the primary phases olivine, clinopyroxene, and plagioclase that can be subdivided into five smaller trends, each between 25 and 80 m thick. Above 1070 maM, phase compositions change to more primitive compositions over a 15 m thin horizon, revealing decameter-scale fractionation trends between 1090 and 1170 maM. Significant zoning in clinopyroxene, that was absent below, is observed above 1070 maM. These trends are confirmed by bulk rock chemical and mineral trace element data and indicate that fractional crystallization occurred within the layered gabbros. The fabric symmetry varies along the core with significant lineation at the primitive base and top of the core and almost pure foliation dominating the most evolved horizon at about 1070 maM. Variable fabric symmetries and the observed differences in clinopyroxene zoning could result from different liquid/solid ratios caused by on-going fractional crystallization and occasional magma replenishment.

Site C0023 in the Nankai Through subduction zone was established in 2016 to investigate the temperature limits of deep subsurface life. Here, we report on the detection of intact polar lipids and their degradation products in sediments recovered from this site where temperatures reach values close to the known limit of life of ca. 120°C at the bottom of the core at 1170 m. Lipid biomarkers characteristic for sedimentary methanogens and unclassified heterotrophic archaea were detected within the methanogenic zone where temperatures transition from mesophilic to thermophilic conditions. These include glycerol, butanetriol and pentanetriol dialkyl glycerol tetraethers (GDGT, BDGT, PDGT) and archaeol with glycosidic headgroups. In this zone, elevated intact polar lipid concentrations compared to vegetative cell numbers suggest substantial accumulation of fossil lipids over time at temperatures of ca. 45 to 50°C. A stark decline in both intact lipids and their degradation products below this depth coincides with the onset of the catagenic zone and the subsequent thermal breakdown of organic matter. The detected lipids are degraded at different reaction rates, reflecting their different thermal stabilities. We also observe a selective removal of GDGTs according to the number of rings in their core structure with important implications for the application of these compounds as paleoenvironmental proxies. This study suggests that intact polar lipids provide a time-integrated signal on microbial community distributions and provides insights into abiotic processes affecting their preservation.

Studying active hydrothermal systems in the deep-sea provides unique opportunities for furthering our understanding of how polymetallic seafloor massive sulfide accumulations form. The possibility of sampling the ore-forming fluids that are emitted through sulfide-sulfate chimneys is particularly powerful. The use of gas-tight samplers in collecting hydrothermal vent fluids facilitates measurements of the contents of dissolved gases and metals and allows for accurate reconstructions of in situ pH and redox conditions.

Metal transport in seafloor hydrothermal systems is affected by fluid-rock interactions, magma degassing, phase separation, and subseafloor mixing of the upwelling hydrothermal fluids with entrained seawater. The composition of basement hosting deep-sea hydrothermal vent systems, i.e. the type of rock involved in fluid-rock interactions, ranges from ultramafic to felsic. Geotectonic settings of vent systems vary from mid-ocean ridges to backarc spreading centers to island arc and intraplate volcanoes, which show strong contrasts in water depths and influx of magmatic fluids. Our recent compilation of vent fluid data (doi:10.1029/2020GC009385) allows a first complete assessment of how these differences affect the compositions of fluids in the root zones of hydrothermal systems. Beyond an examination of these general differences, valuable insights into processes in the discharge zone of hydrothermal systems can be obtained from detailed fluid sampling in individual vent fields. We present examples from selected arc/backarc hydrothermal vent sites in felsic crust for how vent fluid compositional data and thermodynamic computations can yield detailed insights into km-scale metal transport as well as smaller scale processes of zone refining.

The axial volcanic edifice of Maka at the North Eastern Lau Spreading Centre shows intense hydrothermal activity at two vent sites (Maka HF and Maka South) emitting fluids of distinct composition. We present trace element and isotope data for hydrothermal fluids and related sulphide precipitates that actively form on the seafloor at 1525 to 1543 m water depth. Hydrothermal activity at Maka HF is present as vigorously venting black smoker-type fluids reaching temperatures of ~330°C. High metal (e.g. Fe, Mn, Li) and REE contents in the vent fluids, are indicative for a rock-buffered hydrothermal system at low water/rock ratios. At Maka South venting of white smoke at up to 300°C occurs at several sites. Measured fluid pH (4.53-5.42) and Mg, SO₄ and Cl concentrations are depleted compared to seawater, whereas Li, Mn and H₂S are enriched, indicating a three-component mixing model between seawater, a boiling-induced low Cl vapor and a black smoker-type fluid at Maka South. Trace element systematics in hydrothermal pyrite also report on the contribution of these different fluid-types. Pyrite that precipitates from low Cl vapor-rich fluids at Maka South is characterized by high As/Co (>10) and Sb/Pb (>0.1) values that we relate to a boiling-induced element fractionation between the vapor (As, Sb) and liquid phase (Co, Pb). The Se/Ge ratio in pyrite may be used as a new tracer for fluid-seawater mixing. Sulfur and Pb isotopes in hydrothermal sulphides indicate a common metal(loid) source at the two vent sites by host rock leaching in the reaction zone.

Submarine “black smoker” systems and their associated seafloor massive sulfides (SMS) may represent economic resources for future generations. However, the processes leading to spatial variations in the mineralogical and chemical composition of subduction zone-related hydrothermal systems remain poorly constrained. The large submarine caldera of Niuatahi volcano hosts several active hydrothermal vent sites associated with faults at the caldera wall and with young post-caldera volcanic cones, venting vapor-rich and black smoker-type-fluids with temperatures up to 334 °C. We combine bulk sulfide chemistry with in-situ trace element data and S- and Pb isotopes of pyrite, sphalerite, chalcopyrite to decipher key ore-forming processes causing spatial variations in metal(loid) enrichment.

We refer these spatial variations within the caldera to a continuum between magmatic fluid-dominated venting at the central cones (high Cu, As, Bi, Te, Au, Sb, δ³⁴S = -10.6 - 2.7 ‰) compared to fluid-rock interaction and seawater mixing at the caldera wall (high Au, Ag, Cd, Pb, δ³⁴S = -0.6 - 6.3 ‰). Lead isotopes of sulfide separates suggest a connected hydrothermal circulation cell and/or similar source rock compositions in the central part of the caldera compared to a discrete one at the caldera wall. We conclude that metal(loid)s from distinct sources (magmatic volatiles vs. host rock leaching) combined with hydrothermal fractionation (e.g., boiling) leads to spatial variations in economically relevant elements (e.g., Te, Au, Ag, Bi, Se, Co) in submarine caldera-hosted hydrothermal systems. This has important implications on exploration of fossil SMS or volcanogenic massive sulfide deposits on land.

The shallow submarine Kolumbo volcano , located in the 5 Ma-to-present Aegean volcanic arc in Greece, hosts an active hydrothermal system currently forming polymetallic seafloor massive sulfide (SMS) mineralization on the seafloor, with high As, Ag, Au, Hg, Sb and Tl contents. It is one of the few known SMS deposits associated with continental margin volcanism. The hydrothermal system of the Kolumbo volcano represents an active hybrid analogue style of epithermal and VMS mineralization. The particular geological setting of the Kolumbo volcano in the Anydros basin makes it a great natural laboratory to investigate the metal flux as the underlying units outcrop on the neighboring islands of Santorini, Ios and Anafi . To this day, it is not clear to which extend the metals in the fluid derive from a magmatic source or if they are leached from the basement rocks by magmatic-hydrothermal fluids. Whole rock geochemistry of the basement and sedimentary rocks allows identifying the potential metal reservoirs in the system. The basement rocks can add metals to the system either by leaching through magmatic-hydrothermal fluids or contamination of the melt by assimilation. Sulfur and Pb isotope analysis allow to track contribution of the basement rocks to the metals/ligands budget of the fluids by comparison with the sulfates and sulfides of the Kolombo SMS. Constraining the metal reservoirs involved in marine magmatic-hydrothermal systems is crucial to understand the formation of SMS and variability in the metal endowment between the deposits .

Target settings to secure sustainable access to raw materials include seafloor massive sulphide (SMS) resources. Gold-rich SMS deposits, are often the result of complex interplay of multiple Au enrichment events. Recent studies have shown that high-grade Au ores result from Au remobilization from preexisting mineralization, driven by fluid-induced coupled dissolution-reprecipitation (CDR) reactions; however investigations into this process in modern Au-rich SMS, are lacking. To tackle this issue, Au-rich [Au_BULK≤32ppm; Au/(Cu+Zn+Pb)=1.9], polymetallic (Sb, Tl, Hg, Ag, Mo, Te) diffuser chimney samples from the active Kolumbo shallow-water SMS system, Hellenic Volcanic Arc, were geochemically and texturally examined using combined SEM-EDS imaging, and LA-ICP-MS spot analysis and trace element mapping. Recrystallized subhedral auriferous arsenian pyrite2 (≤65 ppm Au, ≤13290 ppm As) records textures, being porosity growth concurrent with the presence of native gold and accessory pore-filling Pb-Sb sulfosalts, indicating that recrystallization proceeded via fluid-mediated CDR reactions. The latter caused replacement of earlier, colloform-banded, Au-rich arsenian pyrite1 (≤130 ppm Au, ≤9057 ppm As) by pyrite2, and liberated invisible Au (nanoparticles and/or lattice-bound) and associated elements (Pb, Sb). Furthermore, textural evidence indicates that porous orpiment with Pb-Sb sulfosalt inclusions, showing extreme Au enrichment (≤861 ppm Au) compared to other SMS deposits worldwide, was formed by replacement of Au- and As-rich Pb-Sb sulfosalts (≤132 ppm Au, ≤6550 ppm As) via CDR reactions. This study provides significant evidence that in arc-related Au-rich polymetallic SMS deposits, native and invisible Au are closely associated to various sulfides/sulfosalts, and CDR reactions may contribute to upgrading Au grades during hydrothermal reworking.

The site selection procedure for a high-level radioactive waste repository in Germany is based on the Repository Site Selection Act (StandAG, 2017) and comprises three phases. Commissioned by the Bundesgesellschaft für Endlagerung mbH (BGE), the BGR contributes to this procedure with the projects „GeoMePS“ and „ZuBeMErk“, which aim to develop recommendations for phase 2 of the site selection procedure – the surface exploration of siting regions. For this purpose, the BGR has developed a systematic approach that includes (1) deducing exploration targets, (2) compilation of geoscientific and geophysical exploration methods in a database structure, and (3) evaluation of case studies of national and international exploration programs. The deduction of exploration targets was based on the criteria and requirements as defined by the StandAG. Subsequently, the identified exploration targets together with a large number of geoscientific (e.g., geological mapping) and geophysical exploration methods (e.g., reflection seismics) were integrated and linked within the database – the so-called “GeM-DB”. All methods were evaluated according to their suitability and applicability for (a) the three defined host rocks (crystalline rock, claystone, rock salt) and (b) the previously defined exploration targets. In step (3) the BGR evaluates national and international exploration programs, for example the site selection processes for deep geological repositories in Switzerland or Sweden, to infer additional exploration directives.The entire systematic approach aims to develop recommendations for a non-destructive and minimal invasive surface exploration program of siting regions in Germany, regarding the lithological, structural, mechanical, and hydrogeological characterization of the different host rock formations.

Seit 2013 hat in Deutschland die Standortsuche für ein Endlager für hochradioaktive Abfälle mit dem ersten Standortauswahlgesetzes (StandAG) neu begonnen. Viele Jahrzehnte lang wurde in Deutschland die Entwicklung von Endlagerkonzepten und Sicherheitsanalysen für ein Endlager in einem Salzstock priorisiert, während Endlagerkonzepte für Ton- und Kristallingestein erst seit zwei Jahrzehnten berücksichtigt werden. Zielstellung eines vergleichenden Standortauswahlverfahrens ist, bis 2031 einen Standort zu finden, der für 1 Million Jahre die bestmögliche Sicherheit für den Einschluss hochradioaktiver Abfälle bietet.

Sicherheitstechnischer Grundgedanke ist dabei der Einschluss der Schadstoffe im sogenannten einschlusswirksamen Gebirgsbereich (ewG). Im Mittelpunkt eines Langzeitsicherheitsnachweises steht folgerichtig der systematische Nachweis des langfristig sicheren Einschlusses der endgelagerten Abfälle durch den Nachweis der Integrität des einschlusswirksamen Gebirgsbereichs, als wesentliche geologische Barriere, sowie der geotechnischen Barrieren.

Aufgrund ihrer einzigartigen Eigenschaften, u.a. Dichtheit und Kriecheigenschaften, werden Salzgesteine in Deutschland und weltweit seit Jahrzehnten bergbaulich und insbesondere für die Energiespeicherung genutzt.

Während Steinsalz in Salzstöcken (Typ: steile Lagerung) vor allem in Nordwestdeutschland verbreitet ist, dominieren in Mitteldeutschland flach gelagerte Salzgesteine (Typ: flache Lagerung) sowie in Teilen Nordostdeutschlands Salzkissen (Typ: Salzkissen). Beide Typen der „flachen Lagerung“ (bedded salt) spiegeln in ihrer lateralen Erstreckung – abgesehen von diagenetisch bedingten Veränderungen – weitgehend sedimentationsbedingte Lagerungsverhältnisse wider.

Ausgehend von der Darstellung der wirtsgesteinsspezifischen Randbedingungen der verschiedenen Salzgesteine fokussiert dieser Beitrag auf die Vorgehensweisen für den Integritätsnachweis des geologischen Barrieregesteins Salz auf Basis vorliegender Erfahrungen und entsprechender Referenzstudien sowie Analogbeispielen. Im Ergebnis wird nachgewiesen, dass Endlagerkonzepte in der flachen Lagerung in der Konstellation Salzkissen aufgrund eines standortspezifischen Multibarrierensystems erhebliche sicherheitstechnische Vorteile bieten.

Claystones in the deep subsurface have various barrier-effective properties for solute transport. Changes in the mineralogical composition (incl. fluids), the structure of claystones in the strict sense, as well for claystone formations in a broader sense, and their regionally different geological development cause a great variety of petrophysical, mineralogical and geochemical properties of claystone sequences. Therefore, sound knowledge of the characteristics of claystone formations is required for the different usage options of the subsurface in order to provide technical support for economic, political and scientific investigations or decisions and to ensure the safety of underground geosystems.

In our study MECHTON existing data will be used and evaluated for petrophysical and further regional characterisation of the lithological expression of claystone formations. For this purpose, statistical methods are used for the interpretation of geophysical borehole measurements in order to record changes in the regional lithological characteristics and the spatial-petrophysical characteristics of a potentially repository-relevant claystone formation, the Opalinus Clay.

The objectives of the study will be presented and methods for characterising the lithological and petrophysical properties of claystone on basis of logs will be discussed. The focus is: How can regionally characteristic properties of claystone be recorded from logs and transferred to a larger study area?

The rock mass around man-made underground structures inevitably experiences major changes in hydraulic and mechanical properties, commonly referred to as excavation damage. In host rock formations for underground nuclear waste storage, such an excavation damaged zone (EDZ) is potentially critical and therefore requires reliable field data sets for safety assessment and the estimation of the long-term behavior. In this study, different on-site measurements were carried out in the EZ-B niche of the Mont Terri Rock Laboratory in order to characterize the EDZ with regard to its changed hydraulic effectiveness and its mechanical and geophysical properties.

The discrete fracture network (DFN) around the EZ-B niche was investigated using a transient airflow permeameter as well as combined microscopic imaging with automatic evaluation. The DFN exposed in the non-lined tunnel with measured hydraulic fracture apertures of 84 ± 23 μm basically represents a network for advective fluid transport. Due to their formation mechanism, we encountered noticeable differences between the newly-formed unloading fractures and the reactivated tectonic discontinuities. Geomechanical and geophysical characterization of the Opalinus Clay was conducted based on needle penetrometer testing at the rock surface. This proved to be a valuable tool for accurately determining the anisotropic uniaxial compressive strength of the claystone, but also led to a general underestimation of other physico-mechanical parameters in bedding-parallel direction, presumably due to unperceived microcracks.

For decades, claystone is investigated as a likely host rock material for the deep geological disposal of highly radioactive waste. To ensure safe operation, knowledge about the long-term (thermo-hydro-) mechanical behavior of clay rock is of significant relevance: How will the excavation induced differential stresses gradually dissipate while causing convergence?

Laboratory triaxial tests on the mechanical behavior allow for the controlling of major and minor principal stress (differential stress), pore pressure (effective stress), saturation, temperature and loading history. Long-term deformation tests running at low differential stresses reveal gradually declining deformation rates (consolidation + primary creep). With time, the deformation process asymptotically approaches an apparently constant deformation rate at constant volume (secondary creep). At higher differential stresses, accelerated tertiary creep occurs, associated with dilatant deformation and forming of new microcracks, leading to final failure of the specimen. In claystones the primary consolidation process is slow and comparatively well understood: due to low hydraulic conductivity pore fluid is slowly squeezed out, at the same time rearrangement of clay particles and micro grains takes place leading to changes in the microstructure. Moreover, rearrangements in the grain skeleton with a variable deformation rate can occur at constant effective pressure. This creep process is hard to determine and still poorly understood. Only very long creep tests give the possibility to detect secondary creep and to distinguish it from primary consolidation processes.

Creep tests run over several months/years on clays from Mont Terri give examples of the settlement mentioned and different types of creep.

In Claystones, the storage concept for spent nuclear fuel mainly consisting of uranium is based among others on the isolation of the radionuclides within the effective containment zone due to the high retention capacity of the host rock. The transport properties are typically determined in laboratory experiments representing the host rock and for defined geochemical conditions. However, previous numerical studies have shown for the Swiss Opalinus Clay, that sorption of uranium and with that the migration are highly affected by variations in the composition of the porewater resulting from mineralogical heterogeneities. The hydro-geological system of the Opalinus Clay is characterized by a 210 m thick, low permeable section embedded between aquifers. The porewater components of the low permeable section show an asymmetric geochemical gradient towards the aquifers due to diffusive exchange over several million years between them. By modelling the past history of the porewater based on multi-component diffusion simulations, we quantify uranium migration for one million years considering the changing geochemical conditions as a result of the hydro-geological system. Our results show, that uranium is retained within the theoretical effective containment zone and adjacent aquifers are not reached. Consequently, a clay rock with a thickness > 100 m in a geochemical and mineralogical framework like the Opalinus Clay would be a suitable host rock for the storage of uranium from spent fuel.

Pure and pristine Archaean and Palaeoproterozoic banded iron formations (BIFs) are excellent marine geochemical archives, especially of original rare earths and yttrium (REY) characteristics. As recently demonstrated for the Mt.Ruker BIF in Antarctica^[1], ultrapure BIFs preserve seawater-like REY distribution with heavy REY_SN enrichment and light REY_SN depletion (SN: shale-normalized). Our results indicate that a prominent feature of the REY signature of seawater throughout Earth’s history has been a super-chondritic Y/Ho ratio which falls between that of potential detritus and the maximum Y/Ho ratio of modern seawater. Another more subtle and fragile proxy of modern seawater is the W-type lanthanide tetrad effect (LTE) which results from the slightly differing bonding characteristics of individual REY in chemical complexes, due to the specific electron configuration of the REY³⁺ ions. This W-type LTE is found in pure marine carbonate rocks and in BIFs, and confirms the primary and marine origin of their REY distribution. The preservation of uniform, super-chondritic Y/Ho ratios in combination with the W-type LTE in chert and Fe-oxide BIF bands is an excellent tool to test the pristineness of geochemical signals in such samples as well as evidence for the primary origin of banding in BIFs.

[1] Ernst D. M. and Bau M. (2021) Banded iron formation from Antarctica: The 2.5 Ga old Mt. Ruker BIF and the antiquity of lanthanide tetrad effect and super-chondritic Y/Ho ratio in seawater. Gondwana Research 91, 97–111.

Rare earth elements (REEs) have become a key component in many technological applications. Due to the rapid increase in their use, the potential environmental exposure has also expanded. However, the effects on the ecosystem have not been yet thoroughly evaluated, leaving many knowledge gaps. To evaluate the effects of REEs, a set of experiments with acute and chronic exposure were performed on photosynthetic organisms.

The effects of acute exposure of four elements (cerium, gadolinium, lanthanum and neodymium) in two set upsexperimental scenarios with different pH values (6 and 4), was evaluated on three testing species: Raphidocelis subcapitata, Lepidium sativum and Vicia faba. In the rResults obtained in the acute exposure, a higher toxicity at pH 4 was observedindicated higher toxicity levels, which could be explained by a higher bioavailability of the elements. From the relative calculated median effective concentrations (EC50s), R. subcapitata was the most sensitive species, followed by L. sativum and lastly, V. faba.

Further investigations focused on , the chronic exposure of lanthanum and cerium was evaluated on Raphidocelis subcapitata. After a 28 days exposure, results showed a growth inhibition effects effect and increasing a bioaccumulation (from day 7 to 28) with effect at the end of the test. Moreover, endpoints regardedfluctuating values of the relative as biomarkers of stress (ROS, CAT, and SOD)., fluctuated during the sampling days during the exposure (day 7, 14, 21 and 28).

Rising rare earth elements (comprising the 15 lanthanoids plus yttrium (REY)) processing and use can lead to increased anthropogenic REY release into the environment, representing a potential environmental concern. Seaweeds due to their key ecological role as primary producers, habitat forming organisms and their tendency to accumulate metals have been largely used for monitoring anthropogenic pollution in coastal areas. In this study we assessed REY contents in Saccarina latissima seaweed to identify potential anthropogenic REY sources, and to relate accumulation patterns to different local abiotic and biotic conditions, including light regime, salinity, temperature and nutrient concentrations which can change over space and time. S. latissima specimens were collected at 2 depths (1-2 m and 8-9 m) in 4 locations at 4 time points (from May to August) along the Norwegian coastline over a germinating season. REY concentrations were analysed in freeze dried samples, each constituted by a pool of 10 specimens, with ICP-MS and relations between seaweed and REY accumulation, growth and protein contents were evaluated. Results provided in this study are expected to deepen the knowledge of the environmental bioavailability and accumulation patterns of REY along a spatial and temporal environmental gradient.

Rare earth elements, comprising the 15 lanthanoids (LN; IIIb in the Periodic Table) plus yttrium are critical elements for a wide range of applications, including new and traditional industries as renewable energy, automotive industries, metallurgy as well as agriculture and medical diagnostics. Rising REY production and use can lead to an increased release into the environment and represents a potential environmental concern. However, the bioavailability and effects of REY and anthropogenic REY-chemical complexes (ACC-REY) remain significantly understudied in aquatic organisms.Here, we evaluated the impact of different REY and ACC-REY on early life stages of two fish species: zebrafish (Danio rerio) as freshwater model species and cod (Gadus morhua) as marine species. Fish embryos were exposed to nominally 2000, 200, 20, 2 and 0.2 µg L^-1 of different REY compounds. Mortality, hatching, larvae development and morphometry were monitored. At the end of the exposure, a subsample of larvae from each treatment was subjected to image analyses to evaluate larvae mobility and behaviour. These individuals were thereafter analysed immunohistochemically to investigate REY impacts on neural activity. First results showed increased mortality and larvae deformation at higher REY concentrations. Further, transcriptomic responses are analysed to reveal underlying molecular effect mechanisms and affected pathways. Results from this study will provide knowledge on the eco-toxicological risks associated to increasing REY release into aquatic ecosystems.

There is a potential risk that geochemical cycles of critical metals (e.g Be and W) will be affected in the pristine environment, when mining of these metals increases to meet the demand in green technology. To understand their geochemical behavior and environmental impact are of high importance to ensure a sustainable development of mine waste and water management. Beryllium and W are identified as elements of potential concern that can have adverse impact on humans and ecosystems. The release of Be and W from two historical skarn tailings (Smaltjärnen and Morkulltjärnen repositories) from the same ore body (Yxsjöberg/Sweden), and the impact on epilithic water diatoms in downstream neutral surface water were studied. Dissolved Be had been released in high concentrations from danalite (Be₃(Fe_4.4Mn_0.95Zn_0.4)(SiO₄)_3.2S_1.4) due to oxidation and acidifications in tailings stored open to the atmosphere (Smaltjärnen). Tungsten was released in low concentrations as an indirect consequence of sulfide oxidation. Thus, CO₃^2- released from calcite buffering the acid produced had exchange with WO₄^2- on scheelite (CaWO₄) surfaces. High concentrations of dissolved W were present downstream the covered and water saturated tailings (Morkulltjärnen). Beryllium and W are considered as immobile elements, but both were transported in neutral mine drainage (NMD) >5 km downstream the mine site. The water quality from both repositories had negative impact on epilithic water diatoms >2 km from the site. This study shows the importance to understand the geochemistry and mineralogy before choosing remediation method for mine tailings enriched in critical metals, and the need to study NMD.

Scandium (Sc) is often included in the group of rare earths and yttrium (REY), but in contrast to the REY, knowledge on its behaviour in the hydrosphere is rather limited. However, a better understanding of the distribution and behaviour of Sc is important, as its use in industry is expected to grow exponentially in future, which will likely result in an increasing Sc release into the environment.

Here, we report and discuss Sc and REY data for the “dissolved fraction” (<0.2 µm) from twelve pristine rivers in Sweden sampled in May 2019. All rivers are characterised by low conductivity (18-60 µS/cm²), slightly acidic to neutral pH (6.04-7.11) and elevated dissolved organic carbon (DOC) concentrations (5.50-10.3 mg/L). Their shale-normalised REY patterns show a slight enrichment of heavy REY (HREY) compared to light REY (LREY), and negative Ce and positive Y anomalies. Some rivers also show a negative Eu anomaly. The REY distribution in these rivers is controlled by nanoparticles and colloids (NPCs) present in the dissolved fraction. Compared to data from 2014, all rivers show higher REY concentrations and a slightly lower HREY enrichment, suggesting a higher NPCs content in the rivers in 2019. Scandium concentrations vary between 0.363nM and 1.17nM and increase with increasing DOC and Fe concentrations. This suggests that Sc has a strong affinity for NPCs, similar to the REY. The association of Sc with DOC further suggests a significant impact of organic ligands on the behaviour of Sc in the hydrosphere.

Mantle convection is a fundamental driving force for the tectonic activity of our planet. It is commonly perceived that mantle convection is difficult to constrain directly. Its processes, however, affect the surface of the Earth and leave an imprint in the geological record. One response to topographic changes driven by mantle convection is the development of unconformities in the geological record (i.e. the absence of a stratigraphic layer), due to non-deposition or erosion. Modern geological maps allow systematic mapping of such unconformable surfaces at the continental scale.

Here we report our recently published work on the extraction of conformable and unconformable contacts (continent-scale hiatus mapping) in geological series across America, Europe, Africa, and Australia, from the Upper Jurassic onward. We find significant differences in the spatial extend of hiatus patterns across and between continents at geological series, ten to a few tens of Million years (Myrs). This is smaller than the mantle transit time, which, as the timescale of convection, is about 100–200 Myrs, implying that different timescales for convection and topography in convective support must be an integral component of time-dependent geodynamic Earth models. For the Cenozoic sedimentary cover of Europe the maps show a large hiatal surface of the Paleocene. This surface precedes the arrival of the Iceland plume and the change in motion of the North Atlantic ridge in the early Eocene.

Our results call for intensified collaboration between geodynamicists and geologists to improve our understanding of interregional-scale geologic events.

The Cenozoic tectonic evolution of Northern Europe involves a number of events that are difficult to reconcile with an intra-plate setting, including magmatic events and topographic changes that are located far from plate boundaries. It is entirely plausible to relate these events to sublithospheric processes in a vigorously convecting mantle. However, traditional mantle convection models are difficult to link to the spatiotemporal constraints provided by geologic archives, because their output invariably depends on the assumptions of poorly known and arbitrary initial conditions. Here we explore a new class of time-dependent global geodynamic Earth models, known as retrodictions, which are based on inverse approach to
reconstruct past mantle flow and structure. Our high resolution, compressible, global mantle flow retrodictions involve more than 670 million finite elements.
Going back 50 million years ago they reveal a preferential flow direction in the sub-European mantle related to material influx from the North Atlantic realm. The retrodictions allow us to track material back in time from any given sampling location, making them potentially useful, for example, to geochemical studies. Our results call for improved estimates on non-isostatic vertical motion of the Earth’s surface – provided, for instance, by basin analysis, seismic stratigraphy, landform studies, thermochronological data, or the sedimentation record – to constrain the recent mantle flow history beneath northern Europe and suggest that mantle flow retrodictions may yield powerful synergies across different Earth sciences disciplines.

The evaporitic Haselgebirge Formation hosts in many places small occurrences of basaltic rocks. The geochemistry of these basalts can potentially provide information about the tectonic setting of the Haselgebirge Formation and the evolution of the Meliata ocean, respectively. XRD analysis and thin sections give hints to the original geochemistry, however the basalts altered significantly in contact with brines. Therefore, we present here 70 new XRF analyses of these basaltic rocks from various localities (Pfennigwiese, Annaberg, Wienern, Hallstatt, Moosegg, Lammertal) and compare the results with previous data from local studies (Gruber et al., 1991; Kirchner 1979; Kirchner 1980a; Kirchner 1980b; Kralik et al, 1984; Leitner et al., 2017; Schorn et al., 2013; Ziegler, 2014; Zirkl, 1957). Based on the concentrations of immobile trace elements (Zr, Nb, Y, Ti), a predominance of MORB-like compositions is observed for the Lower Austrian occurrences and for the locality Wienern (Grundlsee). On contrast, basalts from the localities Lammertal, Moosegg and Hallstatt have predominantly within-plate-type compositions. Both groups plot for the most part in the plume source field after Condie (2003). We discuss a striking regional (east-west) difference of basalt types in terms of existing palinspastic models for the Haselgebirge formation (Leitner et al., 2017; Stampfli & Borel, 2002; McCann et al., 2006).

The Werra-Fulda mining district located in Central Germany hosts a world-class deposit of sulfate bearing potash salts. The Permian (Zechstein, ca. 255 Ma) evaporite sequence was intruded by mafic melts in the Neogene resulting in magmatic dykes as well as sill structures frequently observed in the subsurface mining galleries. Furthermore, volcanic rocks intersect the overlaying strata (mainly Buntsandstein and Muschelkalk) at localized spots forming distinct mountains.

In this study, samples from subsurface mafic dykes and surface volcanic rocks were intensively documented, sampled, and analyzed for their major, minor, and trace element composition. The geochemical analyses allow the characterization of the rocks that show compositions typical for within plate basanites and nephelinites with minor occurrences of phonolitic dykes. Results of the study also indicate the interaction of magma with adjacent potash salts and partly alteration of potassium and sodium concentration.

Two distinct trends in magmatic composition are revealed suggesting at least two sources for the magmatic feeder system in the local area. The geochemical results are compared to published data of the area and nearby volcanic complexes in the Rhön, Vogelsberg, Westerwald, and Siebengebirge. Additionally, we tested the fission-track and (U-Th-Sm)/He dating technique by using apatite from more than 100 magmatic rock samples. Preliminary, results provide two magmatic events: one at about 21 Ma and the other at about 13 Ma. Both events are accompanied by localized tectonic reactivation.

In Germany, the first apatite fission-track study was performed in the Odenwald (Wagner 1968) with the results of Mesozoic apatite fission-track ages. The presentation will re-examine the Mesozoic-Cenozoic exhumation history of the Odenwald and Heidelberg area with new thermochronological data. The Odenwald as part of the Mid-German Crystalline Zone is characterized by outcrops of the Variscan basement and overlain Mesozoic and Cenozoic strata. Towards the West, the Variscan Basement is bound by the Upper Rhine Graben basin and towards the East by the Mesozoic and Cenozoic cover. Variscan basement rocks, Mesozoic, and Oligocene sandstones have been studied by apatite fission-track and apatite (U-Th-Sm)/He thermochronology.

Apatite fission-track ages range between 70.4±3.8 Ma and 116.7±5.2 Ma and apatite (U-Th-Sm)/He ages between 66.4 ± 4.0 Ma and 121.3 ± 16.7 Ma. Apatite of the Oligocene sandstone deposit near Heppenheim revealed a central fission-track age of 49.4±3.6 Ma. The thermochronological data show a differentiated age distribution with cooling ages getting younger from north to south. Consequently, we assume that exhumation of the rocks in the northern part set in earlier a took place slower than in the southern part of the Odenwald. Numerical modelling using the software code HeFtyimplies either a high Cretaceous heat flow or a maximum of up to 2830 meters of Mesozoic sedimentary rocks that could have covered the Odenwald crystalline basement during the Cretaceous. The modelled t-T-evolution hints at two major phases of exhumation, one in the Cretaceous and one in the Neogene.

Proglacial areas are extremely unstable and characterized by highly intensive geomorphic processes. In this study, we consider a typical proglacial area on the Caucuses – Djankuat river catchment. This research presents the first results for the complex monitoring of exogenic geomorphic process rates within the selected catchment. A repeated UAV survey for selected sites conducted in September 2019 and in August 2020 was the primary method. Also, high-resolution DEMs derived from stereo satellite images and the existing data obtained in field observations were used. It was determined that about 4122 ± 179 t yr^-1 enters the glacier’s surface from the located above rockwalls due to rockfalls and avalanches, which corresponds to the erosion rate – 1.29 mm yr^-1. The surface level averagely decreased by 0.48 m between surveys in the river valley just downstream from the glacier. The maximum losses were determined for the glacier front and buried ice outcrops, where values were -1.59 m (buried ice on the left valley side), -2.72 m (buried ice on the right valley side), -3.17 m (glacier front). The highest geomorphic intensity in the proglacial areas apparently associated with the rapid buried ice melting and occurs with a slight delay after the glacier retreat. Specific attention in proglacial areas should be paid to the quantitative assessment of extreme event consequences, which lead to main terrain transformations, sediment yield peak values, and, eventually, to total erosion.

The study was supported by the Russian Science Foundation (project No. 19-17-00181).

The fjord-type Lake Melville is located in Labrador, Eastern Canada, as part of the Hamilton Inlet System. It is mainly characterised by riverine freshwater influx into its western end and intrusion of saline water from the Labrador Sea through the shallow Rigolet Narrows.
Previous studies assumed that the retreating Laurentide Ice Sheet (LIS) caused the deposition of a typical glacial sediment sequence when its margin reached Lake Melville between 10,000 to 8,000 years ago (King, 1985; Syvitski and Lee, 1997). However, as suggested for other sites (e.g. Great Slave Lake; Christoffersen et al., 2008), the up to 400 m thick sediment package might contain pre-deglacial sediment because Lake Melville potentially persisted as a subglacial lake underneath the LIS.
Initial measurements and lithological investigations on two selected sediment cores (~14 m and 16 m) recovered during expedition MSM84 (2019) indicate a significant change in lithology and selected sediment-physical parameters within the lowermost two meters. First 14C-dates of gastropod and bivalve remains resulted in a preliminary age model with an extrapolated basal age of ~11.6 ka cal BP, but hence pre-dating the local deglaciation. In accordance with sediment echosounder data, microscopic investigations and first XRF analysis, we assume that these initial findings point at sediment deposition in a subglacial lake environment. In a next step, we aim at significantly improving the age model by considering more 14C-samples from various sediment cores as well as conducting further multi-proxy analyses to test our hypothesis.

The Eocene-Oligocene transition (EOT, ~34Ma) marks a dramatic climate change and carbon cycle perturbation in the Cenozoic. Understanding the variations in export productivity associated with EOT provides important information about the feedback in regulating climate.
We use the new generated benthic and planktonic oxygen and carbon isotope records combined with paleoproductivity proxies - Biological Barium [bio-Ba MAR] and benthic foraminifera accumulation rates [BFAR] - to infer variations in productivity during the EOT period in relation to changes in climate and paleoceanography.
In addition, we present preliminary diatom diversity data. Marine diatoms have been known to be great contributors to the biological ocean carbon pump, so these data provide support for the understanding of these climatic events.
Samples are from the Atlantic (ODP 689 and 1090) and Indian (ODP 748) sectors of the Southern Ocean. Our multiproxy records show evidence of increased export productivity in different periods throughout the Southern Ocean across EOT. The increase in productivity revealed in the late Eocene (~37 Ma) corroborates with an increase in marine diatoms diversity, suggesting that it could have contributed to the decrease in atmospheric CO2 and consequently to the cooling state.
The timing of some observed changes differs in the sites of the Atlantic sector of the Southern Ocean. The increase in productivity in the early Oligocene in the farther to the south ODP 689 site may be related to the water mass changes and development of the Atlantic Circumpolar Current.

Benthic foraminifera inhabit diverse marine environments, including areas of persistent bottom currents and contourite drift deposition. Certain highly adapted epibenthic foraminifera colonize contourite deposits as opportunistic suspension feeders. A correlation between these assemblages and high bottom current velocities has been highlighted in previous studies from the Iberian Margin (e.g. Schönfeld, 2002), suggesting their applicability as reliable proxy for reconstructing bottom currents.

Our ongoing project aims to document biogeographic patterns of benthic foraminifera from extended contourite drift systems in the Atlantic Ocean. The results will provide a framework to evaluate the applicability of foraminifera-based proxy methods for reconstructing bottom currents in different Atlantic contourite deposits. Existing data from the mid-latitude Iberian Margin are complemented by new faunal data from surface samples at high (50-62°N; Björn and Gardar Drifts, Iceland Basin; Eirik Drift, southern Greenland Margin) and low latitudes (10°-22°S Campos Drift, Brazilian Margin).

Preliminary results show variations in faunal composition along gradients of current intensity. Low current velocities at Björn and Gardar Drifts (max. 10 cm/s) favor tubular agglutinated taxa such as Rhabdammina abyssorum and Saccorhiza ramosa. An association of hyaline attached species including Cibicides refulgens and Cibicidoides wuellerstorfi preferentially settle in intermediate flow speeds at the Eirik Drift (12-22 cm/s). Communities of Campos Drift dwell at higher current velocities (up to 80 m/s) and show increased abundances of Cibicides lobatulus, Globocassidulina subglobosa, and Planulina ariminensis.

Reference:

Schönfeld, J., 2002. Recent benthic foraminiferal assemblages in deep high-energy environments from the Gulf of Cadiz (Spain). Mar. Micropaleontol. 44, 141–162. https://doi.org/10.1016/S0377-8398(01)00039-1

Bottom current-induced sediments such as contourites contain fundamental information for reconstructions of water mass properties and ocean circulation. The distinction between contourites and other deposits on continental slopes is particularly complex in areas where downslope and along-slope sedimentary processes co-occur. Clear and easily applicable diagnostic criteria for properly distinguishing between contourites and other coarse-grained and/or graded deep-water deposits such as turbidites are still limited (e.g., de Castro et al., 2020) and mainly focus on sedimentological data. The present study investigates Pleistocene contouritic (~0.5 Ma) and turbiditic (~0.9 Ma, ~1.1 Ma) sequences from the SW Iberian Margin in the Gulf of Cádiz (IODP Site U1389), where thick contourite drift bodies with extensively intercalated turbidites are preserved (Stow et al., 2013). The aim of the study is to define diagnostic criteria based on benthic foraminiferal assemblage composition in order to differentiate between normally graded contourites and turbidites as well as reworked turbidites. The revealed “foraminiferal fingerprint” will allow for improving paleoceanographic interpretations of sedimentary archives from complex depositional environments along continental margins.

References:

De Castro, S., Hernández-Molina, F.J., de Weger, W., Jiménez-Espejo, F.J., Rodríguez-Tovar, F.J., Mena, A., Llave, E., Sierro, F.J., 2020. Contourite characterization and its discrimination from other deep‐water deposits in the Gulf of Cadiz contourite depositional system. Sedimentology.

Stow, D.A.V., Hernández-Molina, F.J., Llave, E., Bruno, M., García, M., Díaz del Rio, V., Somoza, L., Brackenridge, R.E., 2013. The Cadiz Contourite Channel: Sandy contourites, bedforms and dynamic current interaction. Mar. Geol. 343, 99–114.

The solid Earth aspects of relative sea-level change can dominate in low-lying coastal areas with potentially vulnerable to accelerating rates of sea-level rise. Global Positioning System (GPS) as companion tools to tide gauges allow long-term assessment of solid Earth deformation, thus essential for disclosing climate-forced mechanisms contributing to sea-level rise (SLR). So far, it has not been possible to measure shallow displacements that occur above the base of GPS monument because conventional positioning determines the vertical component of position changes resulting from displacements occurring beneath the foundation. We use an emerging technique, GPS interferometric reflectometry (GPS-IR), to estimate the rate of this process in two coastal regions with thick Holocene deposits, the Mississippi Delta and the eastern margin of the North Sea. We show that the rate of land motion from shallow compaction is comparable to or larger than the rate of SLR. Since many of the world's great coastal cities are built on river deltas with comparable Holocene sections, our results suggest that estimates of flood risk and land loss have been underestimated. We demonstrate environmental impact of parking lots and streets surrounding a monitoring site on GPS measurements. Such kinematic environments will perturb the amplitude of reflected signals to GPS sensors and thus leave time-variable imprints on GPS observations. Thus, obtaining desirable reflections for shallow subsidence monitoring could be challenging.

Natural methane gas release from the seafloor is a widespread phenomenon that occurs at cold seeps along most continental margins. Since their discovery in the early 1980s, seeps have been the focus of intensive research, partly aimed at refining the global carbon budget. However, deep-sea research is challenging and expensive and, to date, few programs have successfully monitored the variability of methane gas release over several weeks or more. Long-term monitoring is necessary to study the mechanisms that control seabed gas release. Located at 800 m depth on the Cascadia accretionary prism offshore Oregon, Southern Hydrate Ridge is one of the most studied seep sites where persistent, but variable gas release has been observed for more than 20 years. Using a series of instruments connected to the Ocean Observatories Initiative's (OOI) Regional Cabled Array observatory, we monitored the venting activity at Southern Hydrate Ridge over several months. We will present results from the systematic monitoring, which include in particular acoustic sensing of bubble plumes and time-lapse photography of selected vents at the seafloor. The data reveal a very dynamic system characterized by frequent and significant changes in seabed morphology and highly variable gas emissions. Acoustic data show how bubble plume variability is linked to the local tidal cycles. Photo and video imagery reveal how intense gas ebullition contributes to rapidly shaping the seabed morphology. This work is funded by the German Ministry of Education and Research (Bundesministerium für Bildung und Forschung). The OOI is funded by the National Science Foundation.

We studied seafloor characteristics, water column anomalies, and sediment methane geochemistry in the German sector of the central North Sea during a research cruise with the German research vessel Heincke in summer 2019. An extensive hydroacoustic mapping campaign revealed the presence and distribution of flares in the water column, indicative for gas bubble releases as well as for geophysical subsurface indications of elevated gas concentrations. We analyzed the spatial distances of detected flares to subsurface salt diapir locations, seismically identified gas accumulations, and abandoned well sites. Continuous and discrete measurements of dissolved methane concentrations in the water column support the identification of seepage from the seafloor. Our data demonstrate that dissolved methane concentrations in the upper water column were not enriched above the studied well sites. At one area, characterized by the presence of shallow gas pockets, we observed methane concentrations ten times enriched compared to background values close to the seafloor. Our results indicate an active natural seep system in the northwestern part of the German North Sea, which is related to updoming salt structures rather than leaking wells, and further underlines that natural seeps may challenge the identification of potentially leaking wells. Due to the shallow water depths of 30 to 50 m in the study area, at least part of the released methane is probably contributing to the atmospheric inventory. This conclusion is based upon our observations of flares reaching close to the sea surface and a slight oversaturation of surface waters in the flare-rich area.

The Mariana forearc provides a unique natural laboratory to study slab dehydration in an active subduction zone by its deep-rooted mud volcanism. To test if mantle wedge serpentinites would record the source fluid composition and thus the dehydration reactions in the slab, we investigated silicon (Si) isotopic compositions (δ³⁰Si) in serpentine veins by in-situ femtosecond laser ablation ICP mass spectrometry. Our samples were recovered during IODP Expedition 366 and originate from three mud volcanoes that root in different depths, so that the pressure/temperature conditions in their source regions vary.

The δ³⁰Si values differ strongly between the mud volcanoes but also between different serpentine generations within individual samples. Serpentine that formed under low water/rock ratios has δ³⁰Si similar to pristine olivine. In contrast, serpentine veins that formed under higher water/rock ratios show large ranges in δ³⁰Si that vary significantly but systematically between the mud volcanoes and thus with the metamorphic grade at depth. Average δ³⁰Si of such serpentine veins are ‑0.10 ‰, ‑1.94 ‰, and ‑0.80 ‰ to ‑0.93 ‰ with increasing depth-to-slab. We interpret these across-forearc changes to record the Si isotopic compositions of the fluid sources, that are at shallow depth (inferred slab temperatures of ~80°C) the dehydration of (biogenic) opal and release of pore fluids, at intermediate depth (~150°C) clay mineral breakdown, and at the deepest point (>250°C) decomposition of clay minerals and altered oceanic crust. These data imply that Si isotope signatures of wedge serpentinites can be used as a reliable proxy for slab dehydration processes.

Subduction is a key process for the plate tectonic cycle and is responsible for the bimodal composition of the Earth’ crust. Whereas active subduction zones can be directly observed at many places, their initiation and the early evolution of the associated volcanic arc can only be studied from the geological record. One key location to study the geological processes related to subduction initiation and subsequent arc emergence and maturation is the Izu-Bonin-Mariana (IBM) subduction zone system in the Western Pacific. Here, a unique record of rocks that formed during the earliest stages of the newly formed subduction zone are preserved in the forearc. However, much less was known about the spatial extent of these lithologies and thus the temporal evolution and the dynamics of subduction zone initiation in the IBM system. In 2014, IODP Expedition 351 added an important perspective by drilling in a rear-arc location, thus complementing the geological record across the proto-IBM arc. In this talk, I will provide a synthesis of the scientific achievements gained through this expedition. The technically challenging drilling recovered a 1.45 km-long section of hemipelagic and volcaniclastic sediments, and 150 m of oceanic igneous crust. New oceanic crust formed analogous to the so-called forearc basalts during subduction initiation, and age and composition of the basaltic crust allow us to constrain the dynamics of subduction zone initiation. The volcaniclastic sediments above provide us with important insights into the compositional and temporal evolution of the volcanic arc over its full lifespan.

The active volcanic arcs of the Scotia- and Caribbean Plate are two prominent features along the otherwise passive margins of the Atlantic Ocean, where subduction of oceanic crust is verifiable. Both arcs have been important oceanic gateways during their formation. Trapped between the large continental plates of North- and South America, as well as Antarctica, the significantly smaller oceanic plates show striking similarities in size, shape, plate margins and morphology, although formed at different times and locations during Earth’s history.

Structural analyses of the seafloor are based on bathymetric datasets by multibeam-echosounders, including data of GMRT, AWI, BAS, MARUM/Uni-Bremen, Geomar/Uni-Kiel and Uni-Hamburg. Bathymetric data were processed to create maps of ocean floor morphology with resolution of 150-250 meters in accuracy. The Benthic Terrain Modeler 3.0, amongst other GIS based tools, was utilized to analyse the geomorphometry of both plates. Furthermore, we used bathymetric datasets for three-dimensional modelling of the seafloor to examine large-scale-structures in more detail. The modelling of ship-based bathymetric datasets, in combination with the GEBCO 2014 global 30 arc-second grid, included in the GMRT bathymetric database, delivered detailed bathymetric maps of both areas.

With the help of the fine- and broad-scale bathymetric position index, we present the first detailed interpretation of combined bathymetric datasets of the entire Scotia Sea, the Caribbean and adjacent areas, such as the South Sandwich Plate. We identified typical morphological features of the abyss, based on determination of steep and broad slopes, ridges, boulders, flat plains, flat ridge tops and depressions in various scales.

The solitary intraplate volcano Vesteris Seamount is located in the Central Greenland Basin and rises around 3000 m above the seafloor with a total eruptive volume of ~500 km³. Newly acquired high-resolution bathymetry allows through backscatter data and raster terrain analysis to distinguish several volcanic structures. The Vesteris Seamount is a northeast to southwest elongated stellar-shaped seamount with an elongated, narrow summit radially surrounded by irregular volcanic ridges, separated by volcanic debris fans. Whole rock geochemical data of 78 lava samples form tight liquid lines of descent with MgO concentrations ranging from 12.6 to 0.1 wt. %, implying that all lavas evolved from a similar parental magma composition. Video footage from ROV dives show abundant pyroclastic deposits on the summit and on the flanks whereas lavas are restricted to flank cones and dike intrusions. The seamount likely forms above a crustal weak zone and the local volcanic stress field increasingly affects the constructive and destructive features on the surface. The evolution of Vesteris Seamount reflects the transition from deep, regional crustal stresses in the older features to local, volcanic stresses in the younger structural features. The Vesteris Seamount enables to understand the structural and magmatic evolution of intraplate volcanoes distant from plate boundaries by combining detailed geological sampling, high-resolution bathymetry and underwater video coverage.

The global objective of achieving net zero emissions is driving significant decarbonisation of energy and transport, with a shift towards renewable energy sources and electric vehicles. It is now widely recognised that this will drive significant increases in demand for a range of minerals and metals, including lithium, graphite, manganese, nickel and cobalt (used in batteries) and the rare earth elements (used in magnets in motors). There are concerns about the security of supply of some of these raw materials, and the increasing demand cannot be met solely by recycling; mining of primary resources will be essential. All of these raw materials can be derived from a range of geological sources, and many deposits are already known, but continued exploration is important. However, a range of other challenges can also impact the raw materials value chain; these may relate to mineral processing, social and environmental impacts, economics and politics. This talk will provide an overview of some of our recent and ongoing research on sustainable exploration, mining, and value chains for critical raw materials for the energy transition.

Epidosites are a prominent type of subseafloor hydrothermal alteration of basalts in ophiolites and Archean greenstone belts, showing an end-member mineral assemblage of epidote + quartz + titanite + Fe-oxide. Epidosites are known to form within crustal-scale upflow zones and their fluids have been proposed to be deep equivalents of ore-forming, black-smoker seafloor vent fluids. Proposals for the mass of fluid per mass of rock (W/R ratio) needed to form epidosites are contradictory, varying from 20 (Sr isotopes) to > 1000 (Mg mobility). To test these proposals we have conducted a petrographic, geochemical and reactive-transport numerical simulation study of the chemical reaction that generates km³-size epidosite zones within the lavas and sheeted dike complex of the Semail ophiolite, Oman. At 250–400 °C the modelled epidosite-forming fluid has near-neutral pH, it is highly oxidized and has low S and extremely low Fe contents. These features argue against the proposal that epidosite fluids are equivalents of black-smoker fluids. The Semail epidosites formed by replacement of lavas already altered to albite–chlorite–actinolite (spilite) assemblages, with the rare end-member epidosites requiring enormous W/R ratios of 700 to ~40000, depending on initial Mg content and temperature. Thus, the variably altered Semail epidosite zones record flow of ~10¹⁵ kg of fluid through each km³ of precursor spilite rock. This fluid imposed on the epidosite an Sr-isotope signature inherited from the previous rock-buffered chemical evolution of the fluid through the oceanic crust, thereby explaining the apparently contradictory low W/R ratios based on Sr isotopes.

The distribution of permeability in the upper oceanic crust controls hydrothermal circulation and the water–rock interactions that feed seafloor mineralization. A prevailing view is that lavas behave as fractured aquifers whose permeability is dominated by major extensional faults flanked by damage zones. Comparatively little is known about the permeability of the km-wide blocks of crust that lie between major faults, yet such blocks constitute huge sources of leachable metals. Our field mapping of hydrothermal veins and pervasive alteration in spreading-axis lavas in the Semail ophiolite enables quantification of the permeability of distal blocks. Fracture length intensities are only ~0.005 m per m² of outcrop, an order of magnitude lower than in major fault zones. Laboratory measurements show the rock-matrix permeability of lava outcrops is ~2.5 x 10⁻¹⁶ m². Numerical hydraulic simulations using dfnWorks software yield bulk permeability of ~5 x 10⁻¹⁶ m² when flow through the fracture network and the rock-matrix are coupled. This demonstrates that the rock-matrix is as permeable as the sparse and unconnected fracture network, consistent with the thoroughly pervasive, rather than fracture-controlled, nature of greenschist-facies hydrothermal alteration observed in the distal Semail lavas. Our observations and calculated bulk permeabilities provide an updated view of fluid flow through the upper crust, in which matrix-flow controls circulation through large blocks of lavas, enhanced by fault-damage zones at km-scale intervals. This new perspective explains how the rock matrix in oceanic lavas is accessible for leaching of metals for seafloor sulphide deposits.

The Troodos ophiolite hosts significant Volcanogenic Massive Sulfide (VMS) systems, well-known as Cyprus-type sulfide deposits. They are mafic type VMS deposits, mainly enriched in copper and zinc and they have been deposited from seawater derived-hydrothermal fluids. Along the Troodos ophiolite, the VMS system is covered by thick, Fe- rich altered caps, known as gossans, which are likely due to weathering of the VMS under oxidizing conditions. However, the conditions for their formation remain largely debated, suggesting either a submarine weathering origin or mineralization weathering on land. Gossans represent a valuable part of the Troodos ophiolite, presenting not only significant amount of extractible copper and zinc, but also, gold and silver. The studied gossans present as mineral assemblage: goethite, jarosite, hematite, alunite, silica, clays, anatase and siderite. Magnetite, ilmenite and gypsum occur as accessory phases. In this study, we show combined data of Cu, Zn and Fe isotopes from three different mines of the Troodos ophiolite (West Apliki, Skouriotissa and Agrokipia), which indicate δ⁶⁵Cu values varying from -3.55 ±0.01‰ to -0.05 ±0.02‰ and δ⁶⁶Zn values ranging from -1.24 ±0.02‰ to +0.34 ±0.05‰. In addition, δ⁵⁶Fe values vary from -0.65 ±0.07‰ to +0.80 ±0.02‰. We aim to investigate the debated origin of the Troodos ophiolite gossans influenced by physicochemical conditions, fluid composition, hypogene ore (e.g., pyrites) and examine the supergene weathering process in VMS systems, based on the redox-sensitive behavior of Cu and Fe, as well as the pH-sensitive behavior of Zn in supergene-weathering environments.

Molybdenum isotope ratios (δ^98/95Mo) of marine sediments constitute an important tracer for paleoredox reconstructions of the ancient ocean. Due to its redox-sensitivity, significant mass-dependent Mo isotope fractionation is induced in present-day low temperature environments leading to distinct Mo concentrations and isotope compositions in different marine lithologies. Subduction and recycling of such fractionated material can thus be potentially traced in arc magmas. Indeed, Mo isotope variations are observed in mafic arc lavas that are attributed to reflect recycled crustal components, but open questions remain to what extent different subducted lithologies contribute to the Mo isotope signature of arc magmas.

We present a comprehensive Mo isotope dataset covering input to output at the Tongan subduction zone, together with exhumed eclogite-facies oceanic crust and sediments from the Western Alps and Alpine Corsica. Pelagic Mn-rich metapelites and MORB-type eclogites reveal that Mo is largely lost during early subduction metamorphism. Moreover, rutile hosts most of the remaining isotopically light Mo in the slab at higher metamorphic degrees where it remains fixed during slab-dehydration processes at subarc depths. Thus, direct recycling of this fractionated material cannot account for the observed positive covariations of Mo/Ce and δ^98/95Mo with fluid indices (e.g., Ba/Th) in Tongan arc lavas. We propose that Mo systematics in Tongan arc lavas are the result of shallow fluid-induced Mo mobilization and forearc mantle serpentinization during early stages of subduction. Subsequent mechanical transport and devolatiziation of this metasomatized forearc mantle material towards subarc regions is a plausible alternative process to recycle Mo and other metals.

Volcanogenic massive sulphide (VMS) deposits have been recognized both in fossil and present-day settings (e.g. mid-ocean ridges (MORs), back-arcs, island-arcs, fore-arcs) and are associated with different lithologies leading to variable metal enrichments. More recently, a sub-type of VMS associated with ultramafic rocks has been discovered at MORs. These ultramafic-hosted VMS (UM-VMS) form in genetic relationships with detachment faults exhuming mantle rocks and are commonly enriched in base (Cu, Zn, Ni), critical (Co) and precious (Au, Ag) metals. However, they are thought to be scarce in the geological record since they are unlikely to obduct from MOR settings.

We propose, based on an extensive review of worldwide UM-VMS deposits described in ophiolites, that this scarcity is only apparent. Previously, UM-VMS have been commonly misclassified for three main reasons: i) the tectonic settings in which they form has been misinterpreted (e.g. tectonic mélanges), ii) their origin may be disputed (hydrothermal vs. magmatic) and iii) orogenic-related metamorphism and deformation locally obliterated seafloor-related mineralogical and structural features. Also, the strong focus on UM-VMS formed in MORs prevented to recognize them in other settings such as ocean-continent transition or supra-subduction zones which are more easily preserved in the geological record. Here, we discuss discriminant features applied to fossil UM-VMS worldwide which allow us to classify them as such. We show that UM-VMS are not as scarce as previously thought and, hence, represent possible undiscovered metal resources. Further genetic and exploration models are needed for new discoveries.

Mid-Oceanic ridges are places of intense fluid-rock interactions. At (ultra)slow-spreading ridges where mantle rocks are exhumed along detachment faults, this notably leads to the formation of mineralized systems. They commonly form massive sulphides at the seafloor which are enriched in base (Cu, Zn, Ni), critical (Co) and precious (Au, Ag) metals. However, the limited conditions of observation at the seafloor lead to partial rather than integrative understanding of these hydrothermal systems, especially concerning deep hydrothermal processes. Alternatively, the study of fossil analogues preserved on-land offers the opportunity to study these systems in 3D and to access the deep hydrothermal plumbing system of such mineralizations.

We adopted this strategy here and focused on a mineralized system preserved in the Platta nappe (SE Switzerland), a remnant of the Jurassic opening of the Alpine Tethys Ocean. As a rule, the hydrothermal system escaped strong Alpine overprint. In the Platta nappe, detachment faulting led to mantle exhumation against basalts. Associated HT fluid circulations led to the formation of mineralizations in the serpentinized footwall at the lithological interfaces with mafic intrusive rocks, suggesting the latter acted as preferential pathways for fluid flows. The Cu-Fe-Co-Zn-Ni mineralization forms massive, semi-massive sulphides and stockwork structures. It mainly consists of chalcopyrite, pyrrhotite, pentlandite, isocubanite and magnetite associated with Fe-Ca-silicates (ilvaite, hydro-andradite and Fe-diopside). Based on structural and petrographic features, the hydrothermal system of the Platta nappe is inferred to represent the root zone of present-day hydrothermal systems.

Groundwater quality degradation is a well-recognized phenomenon and has received considerable attention since the industrial revolution. In spite of this, many aspects concerning the understanding and management of groundwater as a resource remain complex, and adequate information, in many cases, remains elusive. Strategies to protect and manage groundwater quality are often based on limited data and thus restricted system knowledge.

As questions remain about the behaviour and prediction of well-known groundwater contaminants, new concerns around emerging contaminants are on the increase. In urban, industrial and agricultural areas especially, groundwater quality is widely compromised by anthropogenic impacts. Water management in such areas is recognized as a very complex task, in terms of different spatial and temporal scales, as well as understanding the input mechanism, transport and attenuation processes: crucial for sustainable groundwater management. The residence time of contaminants within groundwater bodies can be anywhere from weeks to decades, depending on physico-chemical properties of compound and environmental conditions. It is therefore well-accepted that subsurface heterogeneity necessitates the application of multiple tracers and methods to minimizing uncertainties and to uncovering subsurface processes that would not have been identified by the application of e.g. only one tracer. Thus, although contaminants are typically unwanted, they can provide crucial insights into flow and transport processes within aquifers.

This presentation highlights some of the key contaminants that originate from anthropogenic activities, reviews some of the major controls on groundwater contamination, and includes a case study that addresses historic and emerging issues in contaminant hydrogeology.

Emerging micropollutants such as lifestyle drugs, pesticides, and pharmaceuticals are increasingly detected in the aquatic environment. To counter possible threats posed by these pollutants, their transport behaviour needs to be thoroughly understood.

In this study, 22 laboratory column transport experiments were conducted at selected pH and Na⁺ concentrations with natural quartz sand as sorbent to determine transport behaviour of the beta-blocker metoprolol (MTP, pK_a=9.67) at various conditions. MTP breakthrough curves were measured at pH 3, 6, and 11, as well as NaCl concentrations of 1, 10, and 100 mM/l to account for coupled effects. The observed mean R ranges from R=1.04 (pH 11; 100 mM/l NaCl) to R=10.5 (pH 5.6; 1 mM/l NaCl).

An ion exchange equation was used to model CEC and exchange coefficients of Na⁺, H⁺ and MTP using a least square refinement routine considering the whole dataset of 43 retardation values.

With the model, a high R-regime at low cation concurrence (c(NaCl)~1 mM/l) and neutral pH (5<pH<9) could be identified. Decreasing of retardation can be attributed to: (1) increasing Na⁺ concurrence, (2) decreasing pH at pH<5 due to lowered zeta potential and i.e. negatively charged sites covered by H⁺, and (3) increasing pH at pH>8.5 as a result of changing MTP speciation.

Nitrate is one of the dominant chemical pollutants of groundwater, and there is a need to mitigate groundwater pollution in rural, urban and industrial terrains in an aquifer system. The study assesses the extent of nitrate pollution in the Densu Basin because of its predominance in agriculture and urbanized vicinities by employing robust techniques for estimating both the natural background and human-induced concentrations. The statistical methods used to estimate these concentrations are the pre-selection method, graphical approach (probability plot),non-parametric approach (kernel density estimation), and parametric approach (Gaussian mixture model). The study shows that the Gaussian mixture model is robust enough in determining the spectral distribution and clustering of the nitrate concentration in the basin. It estimated the natural background and human-induced concentration at1.7±1.3 and 9.8±5.6, respectively. The results show that the natural background concentration in the basin is more dominant and hence, conducive for drinking. Also, we show that26%of anthropogenic sources have leaked into the natural groundwater of the Basin. The data suggest that the nitrate concentration in the Densu aquifer system is sourced from agricultural input, domestic effluent and atmospheric deposition. High nitrate loading was observed in areas of active agricultural activities (Suhum, AkwapemNorth, Ayensuano and Upper West Akim). These areas should be protected from further anthropogenic exposure

The identification of contamination sources is vital for water protection, especially in highly vulnerable karst aquifers. Contamination sources might be distinguished by host-specific DNA markers of bacteria (Microbial Source Tracking, MST) or source-specific indicator compounds (Chemical Source Tracking, CST). These methods can help to identify a type of contamination source but fail to distinguish similar contaminant signals from different origins, e.g. multiple points of wastewater infiltration. Transport modelling can reduce these ambiguities by considering the time course of contaminant concentration, thereby allowing for a better allocation of the input source. However, flow in karst aquifers is highly heterogeneous and very dynamic. Hence, distributed numerical transport models on catchment scale are complex, difficult to parameterise and suffer from manifold ambiguities.

Here, an approach is presented, which aims at improving identification of contamination sources by combining MST/CST with transport modelling. Fast (conduit) transport is represented by a 1-D problem and a maximum transport distance for contamination events is modelled. The model is based on (semi-)analytical solutions of transport models, well-established in tracer test analysis to estimate apparent tracer velocities. In this study, a-priori knowledge about velocities and input times is used to inversely model transport lengths from contaminant breakthrough curves.

The inverse transport model (implemented in GNU Octave) was validated and parameter sensitivities were analysed. The maximum transport distance approach was shown to perform well during periods of flow recession. It was applied successfully to a contamination event at a karst spring and allowed for assigning its input to a stormwater tank.

In alpine regions, karst springs are important sources of drinking water but highly vulnerable to temporary contamination, particularly in response to rainfall events. This variability of water quality requires rapid determination methods of contamination parameters. In this study, we present a multi-parameter approach to determine the dynamics of fecal bacteria, organic carbon and particles at alpine karst springs.

Conventional cultivation-based analysis of fecal bacteria such as E. coli is time-consuming. The measurement of the enzymatic activity of E. coli could prove to be a valuable tool for water-quality monitoring in near real time. We used an automated device (ColiMinder) to measure β-D-glucoronidase (GLUC) at an alpine karst spring. To assess the relations between GLUC activity, discharge dynamics and contamination patterns, multiple hydrochemical, physicochemical and microbiological parameters were measured in high resolution. We observed strong correlations between small particles (1.0 and 2.0 µm), conventional E. coli results, ATP measurements and total organic carbon. These parameters also show strong and significant negative correlations with the electrical conductivity. At high contamination levels, GLUC activity also reveals good correlations with E. coli and small particles.

The results demonstrate that the investigated karst springs showed fast and marked responses of all investigated water-quality parameters to rain events. At high contamination levels, GLUC and particle-size distribution are suitable parameters for the rapid assessment of bacterial contamination in high resolution. While GLUC activity alone cannot substitute conventional determination methods, a combined use of these parameters is a promising approach for an early-warning system regarding bacterial contamination.

Public access to geological data, especially to data from commercial subsurface geological investigations, was claimed for a long time in the German geoscience community. Since June 30^th 2020, the Geological Data Act (Geologiedatengesetz, GeolDG) regulates the public availability of this data and replaces the Mineral Act (Lagerstättengesetz) from 1934. The GeolDG implicates both duties for persons who carry out or commission geological investigations and for the competent authorities, which are Geological Surveys. The “Landesamt für Bergbau, Energie und Geologie” (LBEG), as the Geological Survey of Lower Saxony, currently designs a digital application to organize the entire notification, data management and administration procedure, including the processes of registering geological investigations, of transmitting geological data, of generating administrative decisions, and of releasing data to the public according to the given regulations and deadlines. The current online application for registering boreholes, the “Norddeutsche Bohranzeige Online”, will be adapted and implemented into the new system. Following the legal guidelines, further categories will be other site-specific geological investigations such as outcrop studies or examinations of mining sites, investigations of areas or transects such as field mapping or geophysical surveys, and re-investigations of existing geological data such as geological models or reports developed from publically available data. One objective of the new application is to enable users to correctly notify the LBEG about any kinds of geological investigations, to retrace their own notifications, and finally to upload the geological data in the requested data format.

In 2014, an analysis showed that EU had funded geoscientific data harmonisation projects with several hundred thousand Euros but that only a small fraction of the results were sustained a few years after the projects ended. EuroGeoSurveys therefore decided to establish the EGDI which was first launched in 2016. This version consisted of a web GIS, dedicated GIS viewers for specific geoscientific topics, numerous distributed web services, a metadata catalogue, a database for pan-European harvested data, and it gave access to over 600 layers from 13 projects.

EGDI provides a pipeline of data and knowledge through which the geological surveys connect strategically and technically with the wider European Research and Digital landscape.

In 2018, the Horizon 2020 ERA-NET GeoERA was launched with 14 projects, all of which generate large amounts of pan-European and cross-border data sets. EGDI is the platform to safeguard, harmonise and disseminate all this information. Through a dedicated project (The GIP-P), EGDI is being substantially extended with a document repository, a search system, a 3D database, vocabularies, a user support system and eLearning platform, etc. When GeoERA ends in October 2021, EGDI will give access to results from a total of 37 projects covering on- and offshore geology, raw materials, geoenergy, groundwater, geohazards, geochemistry, and geophysics.

Future plans focus on further developing EGDI under a Horizon Europe Coordination and Support Action where EGDI will move towards becoming a knowledge infrastructure.

The presentation will explain about the system, the challenges and lessons learned from the last 5 years.

Since 2019, the LGRBwissen internet portal provides freely accessible and reviewed geoscientific information for the state of Baden-Württemberg. With LGRBwissen, the State Office for Geology, Natural Resources and Mining (LGRB) is expanding its product portfolio with supplemental descriptions of digital geoscientific data (GeoLa). Although LGRBwissen is primarily designed for professional customers of the LGRB, easily understandable information for the interested public is offered in several sections.

The core of the portal is a tripartite search tool. Besides using a free text search, it is possible to filter thematically by subject and to search spatially. The spatial search is possible by digitizing a polygon in a map application or by entering a location name directly. The latter opens a list with pre-configured administrative units, such as municipalities or districts.

In the central part of each page, there is an interactive map with an overview of the specific geoscientific topic described. The map navigation follows established internet standards. The level of generalisation is automatically depending on the map scale. In addition to the geoscientific descriptions, LGRBwissen contains a geoscientific glossary, picture galleries, links to the detailed information about the mapping units and further publications of the LGRB downloadable as PDF files.

As a modern and attractive tool, LGRBwissen has significantly improved the knowledge transfer from the LGRB to its customers. Furthermore, the interdisciplinary linkage of contents creates numerous synergy effects for administration, science, education, and business.

LGRBwissen can be reached at https://lgrbwissen.lgrb-bw.de.

Due to constantly changing requirements and needs for easy access and use of geoscientific data, the technology and methods to provide and present this type of data have recently evolved remarkably and will undergo more changes in the time to come. The aim is to address broader user groups in addition to the original group of experts ranging from non-experts to even the public to support decision making and participation in projects and initiatives.

What used to be classical data portals providing purely access and download of data or consumption of data services will be supplemented with more ways to explore and analyze data in focused apps right away without switching to expert tools. New and tailored visualizations allow users with specific backgrounds to make better decisions and draw the right conclusions within the context needed.

More and more, new data hubs and federated portals and platforms in the cloud or on premise allow collaboration between different domains. Direct connections and interfaces between these domains nurture integrated and interdisciplinary value chains. Focused apps such as dashboards and storymaps support new experiences of data.

The lecture gives an overview and shows existing examples of these new offerings including the geological domain

The presentation of 3D-data is gaining a crucial role for the government agencies in Germany. With the introduction of new federal laws on data storage and release, it became important to present 3D-data in an accessible way to everyone. Since the general public can handle web browser applications easily, unlike desktop applications, web-based technologies should be implemented for data presentation. A good user experience and a valuable access to the data requires that a number of components within a web technology need to work together in both back end and front end.

A 3D-viewer with web technology requires minimum configuration to run. Any web application has standard technologies like programming languages PHP, .Net 5 or JavaScript, a descriptive language HTML and a hosting server with a particular software environment (LAMP). In addition, to visualize the 3D-data, it is necessary to integrate a 3D-engine, e.g. WebKit, and optimize data transfer between a database and a client. However, there are limitations of 3D-data presentation with web applications. For example, a 3D-engine retards performance and interaction with users.

We have implemented full stack components of a 3D-viewer with developed web technologies for our own NIBIS3D-viewer at the State Authority for Mining, Energy and Geology of Lower Saxony. In our work, we show that these 3D-viewer components comprise a good running system for the visualization of 3D-data and represent a complete infrastructure from server over back end to front end interfaces for users.

More than 15 years ago the geographical information system GisInfoService was implemented as part of the project ‚GeoRohstoff‘ of the former Commission for Spatial Information Economics (GIW-Kommission). Sponsored by the German Aggregates Associations the purpose of this web application has ever since been to provide the companies of the quarrying industry with relevant spatial information, such as aerial photography, geological and hydrological data or information about land use or conservation areas. Fast access to these facts is fundamental not only for planning processes but also for everyday tasks and the quick generation of maps for presentations.

GisInfoService makes use of the infrastructure for spatial information that has been built up in the last one and a half decades. It integrates official data by means of web map services published by public authorities (e.g. land surveying offices or geological surveys). If required, there is the option to expand the mere web viewer of GisInfoService by combining it with a data warehouse that contains operational data such as quarry development plans or information on land property, lease, contractual terms or quarry permits.

Presenting the geoportal GisInfoService should give an example how geoscientific data and other public sector information is used by German quarrying companies and their associations for their purposes.

Historically, basin and petroleum system modeling has mainly focused on understanding the burial and thermal history of sedimentary rocks as well as related hydrocarbon generation from kerogen (sedimentary organic matter) in source rocks; much less studies treated hydrocarbon migration and accumulation in great detail, although it is of uttermost importance for petroleum exploration and production. New 2D and 3D basin models in different parts of the Persian Gulf indicate the variable complexity of hydrocarbon migration in this region. A complex migration pattern including sequential filling, spilling and refilling of the structures are assumed for the northern part of the basin, whereas in the southern part simple lateral migration over distances of hundreds of kilometers is reasonable. Besides geometry of the basin, tectonic evolution of structural highs and facies variations are the controlling parameters on the direction of hydrocarbon migration and accumulation in the northern part. While there is a presumably minor effects of the fault systems on the burial and thermal history, their role as hydrocarbon conduits and therefore controlling the hydrocarbon accumulation and geochemical properties are of great importance. The results provide key information on charge history and understanding of the Cretaceous-Tertiary petroleum systems and genetic distribution of oil families in the Persian Gulf. It also reveals the possible causes of exploration failures and hints for future hydrocarbon exploration potential.

Organic matter rich rocks are the main component of any petroleum system. Marine organic matter deposits form a major part of these rocks and are the source of most oil. Vertical and lateral heterogeneities in marine petroleum source rocks are widely observed and owed to the dynamics of deposition and preservation of marine organic matter. Such source rock heterogeneities add major challenges to hydrocarbon exploration and estimation of resources, therefore, quantification of source rock potential using numerical prediction tools can contribute significantly to reducing exploration risks and enhancing the accuracy of resource assessment.

We introduce here our innovative approach to modelling marine petroleum source rocks as part of an established forward stratigraphic modelling workflow. This enhanced workflow only requires minor additional input to a regular forward stratigraphic model in order to simulate marine source rocks deposition and preservation. Modelled source rock properties with this method include TOC, HI, thickness, net to gross, lithology, and other depositional environments properties allowing a sound source rock potential assessment.

Additionally, we assess uncertainty, sensitivity, and risk on source rock potential using an innovative response surface modelling approach which provides an efficient and effective way to understand the controls on any output property and quantify the associated risk.

To illustrate this new methodology, we will present the case of the Mesozoic Carson Basin offshore Newfoundland and Labrador, Canada.

Any attempt at modelling natural phenomena includes a number of numerical assumptions on which we have little or no constraints. Basin and forward stratigraphic modelling are methodologies that aim at reproducing the history of sedimentary basins and their internal complexities. As are all deterministic models, these models are characterized by the none-uniqueness of their results. Meaning very different models can equally honor the calibration data. The traditional approach to such a problematic is a Monte-Carlo approach which requires running 100s or 1000s of simulations in order to capture the uncertainty and quantify the risk on an output of interest (e.g. Source rock maturity, charge, source rock presence, reservoir presence…). Such a large number of simulations requires days or weeks of computation and is thus not suitable for the operational needs of the industry.

In this presentation we will introduce an innovative approach for an efficient and effective sensitivity and risk analysis using response surface modelling. This method requires a small number of simulations, out of which a response surface can be constructed to mimic the behavior of the calculator. The predictivity of the response surface is checked with confirmation runs. The response surface can then be interrogated and producing thousands of results instantly for a thorough and quick sensitivity and risk analysis.

This method can be applied to basin and forward stratigraphic modelling and the analysis can be done on maps (whole model or per interval), along planned well paths (vertical or deviated), and in scalar mode.

The Böllstein Odenwald is forming a large anticline of mainly pre-Devonian rock in the Mid-German Crystalline Zone (MCGZ). The contact between core and schist envelope of the anticline is well exposed at Weichberg quarry. Metasedimentary rocks of the schist envelope are intruded by granodioritic sills of a Silurian magmatic arc, showing at least two folding phases: Recumbent tight isoclinal folds are overprinted by upright gentle folds. A pegmatite dike, intruding at 411 ±2 Ma (U-Pb analyses on zircon) into the schist envelope rocks, crosscuts perpendicular to the main foliation. It shows only a weak schistosity related to the isoclinal folding, which therefore must have been active in Lower Devonian (>411 ±2 Ma; Lochkovian/Pragian) after the Silurian intrusion of the granodiorite sills (U-Pb on zircon ca. 423 Ma, Dörr et al. in press). The Lower Devonian deformation of the East Odenwald probably results from the collision of the MGCZ with the NW boundary of the Saxothuringian Zone.

The core is represented by a (meta)granite intruding into the schist envelope at 404 ±2 Ma (U-Pb method on zircon). A deformed fold directly at the contact between metagranite and metasediments and dikes terminated at the contact point to eastward directed tectonic movements between core and schist envelope after 404 ±2 Ma, probably at 375 Ma (U-Pb on zircon, Todt et al. 1995). These results are compared to other units occupying a similar position in the European Variscides and help to clarify the position of the East Odenwald during Variscan orogeny.

Here we investigate the thermal structure of the lithosphere in the Alpine-Mediterranean region. We focus on areas characterized by negative velocity anomalies according to a lithosphere-upper mantle surface-wave tomography study (El-Sharkawy et al., 2020) to analyze possible lithospheric thinning and melting. Surface-wave, phase-velocity curves were determined by interstation cross-correlation measurements and inverted for a set of phase-velocity maps, spanning a broad period range. We invert fundamental mode Rayleigh and Love dispersion curves together with surface elevation and heat flow for the 1D thermochemical lithospheric structure in 13 columns. The inversion is framed within an integrated geophysical-petrological setting where mantle seismic velocities and densities are computed thermodynamically as a function of the in situ temperature and compositional conditions (Fullea et al., 2021). We analyze the presence of small amounts of melt in the vicinity of the lithosphere-asthenosphere boundary. We conduct sensitivity tests to asses the uncertainties associated with alternative experimental results accounting for the effect of melt and water on seismic velocities. Our results show that the lithosphere is thin (60-90 km) over the whole negative velocity anomaly area in the Alpine-Mediterranean region. We find the thinnest lithosphere in the Pannonian and Tyrrhenian basins (60-70 km), while the thickest lithosphere is located in the Iberia and Central Europe (80-90 km). Our thermal models show the presence of melting near the LAB (1300 ºC isotherm) in some of the columns (e.g. Pannonian and Tyrrhenian basins) associated with a pronounced drop in Vs velocities.

Recent evidence suggests that the Eifel Volcanic Fields (EVF) make measurable contributions to the surface deformation in GPS networks, but quantitative assessments of displacement time series and their impacts on long-term rates are lacking. The GPS sites in the EVF indicate anomalously slow uplift (up to 1 mm/yr) which stays at the limit of GPS sensitivity and noise level for monitoring crustal deformation in geophysical applications. Since the primary aim of existing geodetic GNSS networks in west Germany is positioning service for land survey engineering and transportation applications, many sites have been installed on inexpensive and non-geodetic monuments, thus highly vulnerable to disturbances resulting from monument instability and near-field multipath sources. These potential pitfalls have not been fully addressed in previous studies. Here, we reprocess all available GNSS observations (combined GPS and GLONASS observations) using precise point positioning technique and present precise analysis of displacement time series to generate reliable long-term rates and uncertainties. Individual time series is examined to determine local motion, non-linear deformation due to regional and local hydrology and site-specific noise.

Volcán de Colima is active andesitic stratovolcano in México located at the height of about 3860 m above sea level. It belongs to the Colima Volcanic complex within the Trans-Mexican Volcanic Belt. This volcano is characterized by intermittency of explosive and effusive episodes of volcanic eruptions. For 2007-2009 slowly extruded magma led to a lava dome formation and growth in the volcanic crater. In this work, we present two-dimensional numerical models of the lava dome growth, which have been computed on the KIT SCC bwunicluster using the Ansys Fluent software. The aim of the numerical study is to understand the link between the rheological properties of the lava dome and the morphological shapes of the dome. Numerical models of lava dome growth incorporate the crystal growth kinetics and the realistic topography of the crater floor. We consider several scenarios of dome growth with different conduit shape, initial and equilibrium crystal contents to analyze the model parameters controlling the morphology of the growing dome. The extrusion rate, the characteristic time of crystal content growth in lava, and the characteristic lava viscosity have been used as tuning parameters to optimize the difference between the morphological shapes of the observed and modeled domes. The numerical results show a good agreement with observations and allow constraining the viscosity of lava dome.

The culture around sharing our data and software is evolving. Funders are starting to provide more clarity and requirements. Institutions are working to provide support and incentives. And journals are requiring that data be cited with some improvement on software as well. And yet, it is still difficult. Not all data can be shared. Not all data can be cited.

As us celebrate our progress we must also strengthen our collaboration and efforts in addressing the current challenges and those to come. Achieving FAIR, open and reproducible research through data and software management and preservation is both difficult and rewarding. Governance and sovereignty as represented by the CARE Principles give us a framework to expand research stakeholders to the people and community. In this talk we will share approaches that the AGU is taking to share data and software with stakeholders of the research ecosystem for better science, decision-making, and transparency. Persistence is necessary. Flexibility is key.

NFDI4Earth addresses digital needs of Earth System (ES) Sciences (ESS). ES scientists cooperate in international and interdisciplinary networks with the overarching aim to understand the functioning and interactions within the Earth system and address the multiple challenges of global change.

NFDI4Earth is a community-driven process providing researchers with FAIR, coherent, and open access to all relevant ES data, to innovative research data management (RDM) and data science methods. The NFDI4Earth work plan comprises four task areas (TA), of which TA1 and TA2 are first introduced here:

TA1 2Participate will engage with the ESS community and secures that NFDI4Earth is driven by user requirements: Pilots, small agile projects proposed by the community leverage existing technologies and manifest the researchers’ RDM needs. The Incubator Lab identifies promising new tools and scouts for trends in ES Data Science. EduHubs produce open, ready to use educational resources on implementing FAIR principles in the ESS. The Academy will connect young researchers and their data-driven research to NFDI4Earth.

TA2 2Facilitate realizes the OneStop4All as the web-based entry point to FAIR, open and innovative RDM in ESS. It supports on how to find, access, share, publish and work with ES data. Specific user requests beyond the scope of the OneStop4All will be routed to a distributed User Support Network. TA2 will also unlock the wealth of data that exists in governmental data repositories and will collaborate with all services on supporting long-term archiving.

TA3 2Interoperate and TA4 2Coordinate will follow as a second abstract.

NFDI4Earth addresses digital needs of Earth System (ES) Sciences (ESS). ES scientists cooperate in international and interdisciplinary networks with the overarching aim to understand the functioning and interactions within the Earth system and address the multiple challenges of global change.

NFDI4Earth is a community-driven process providing researchers with FAIR, coherent, and open access to all relevant ES data, to innovative research data management (RDM) and data science methods. The NFDI4Earth 2021-26 work plan comprises four task areas (TA), of which TA3 and TA4 are finally introduced here:

TA3 2Interoperate aims at interoperability and coherence of the heterogeneous, segmented range of ESS RDM services. The ecosystems of ESS (meta-)data and software repositories, data science services and collaboration platforms get integrated iteratively into a common NFDI4Earth architecture. Based on commonly agreed-upon standards TA3 provide consistent methods for a self-evaluation of RDM offerings. TA3 works on NFDI cross-cutting topics and makes outcomes accessible as a Living Handbook. It ensures co-operation in international RDM initiatives and standardisation bodies.

TA4 2Coordinate facilitates the overall management of the NFDI4Earth consortium. TA4 acts as central support service and coordination of the technical implementations. It also offers virtual research environments. The NFDI4Earth Coordination Office will support the NFDI4Earth community in day-to-day operations and acts as the NFDI4Earth point of contact. It develops a commonly agreed model for a sustainable operation of NFDI4Earth.

A commonly accepted NFDI4Earth FAIRness and Openness Commitment is key to fostering a cultural change towards FAIR and Open RDM in the ESS community.

Digitalisation and FAIR data are overarching elements in the Helmholtz Research Field Earth and Environment (RF E&E) Program-Oriented Funding Phase IV (PoF IV). Already in the transition years from PoF III to PoF IV (2019/2020) different measures were implemented to facilitate this aim. One of them is the so-called DataHub, with the aim that all Earth System (ES) data that is generated by the RF E&E will be available as FAIR data via a common access point. To achieve this, three thematic SubHubs have been created: for atmospheric data (ATMO), for maritime data (MARE, also including DAM) and for terrestrial data (TERRA). The three SubHubs (ATMO, MARE, TERRA) are interlinked by thematic working groups and are continuously developed. In addition, the SubHubs are undergoing a continuous integration process that aims at a common access point and improved interoperability of data, products and services. Here, a presentation via web-based services will be available soon, with common thematic viewers that also provide stakeholder relevant products, in addition to the actual underlying data. The DataHub will be maintained and continuously developed as a long-lasting project that will also support aspects of the NFDI process in general and the NFDI4Earth in particular, thus benefiting the ES sciences in Germany in general.

Open data and open-source code are influencing each other: the availability of open data sparks new developments for data analysis and processing. Open-source codes on the other hand have the potential to show the value of open data. This symbiotic effect is well visible in the successful recent developments in the field of machine learning, which was strongly influenced by open data sets and benchmark tests, for example in the famous Kaggle competitions.

We outline here the evolving landscape of open-source software developments for (subsurface) geoscience applications. Our overview includes codes and software packages for processing of typical geological and geophysical data sets (borehole data, seismic data, wireline logs, geological maps, outcrop and laboratory data etc.), as well as packages for data processing, up to full 3-D geological modeling and geophysical inversion approaches.

The long-term maintenance of these packages is often a challenge, especially when they are developed in research projects. But a combination with open geological data has the potential to lead to transparent and reproducible decision processes, which are relevant in many cases where geological subsurface investigations are used for public decisions such as evaluating possible nuclear waste repository sites or for geothermal energy exploration.

A high number of 3d geological models are produced every year at mining companies, geological surveys, consulting offices and many other institutions. Many of these models are being created by different authors and usually have a slightly different purpose and need to meet different demands. Yet the underlying geology stays the same.

While the data providers can publish a variety of 2d data sets 3d are lacking behind. This leads to a loss of knowledge, e.g. when domain experts have been creating a particular 3d model and refined it over the years but also to the loss of investments. The whole creation process must be executed by a second modeler.

With a database for 3d models the existing and new models can organized in such way that they are centrally accessible. In a first step within the organization. In further steps models might be shared with a broader audience. A flexible data model should be easily applicable and allow to apply any metadata model to the data to make it even easier to find the desired data.

In order to not only act a data silo a management system should provide an API such that the data is interoperable and allows to implement any needed data format or moreover to reuse the data directly in different programs or scripts.

With GST its users are being enable to layout a foundation for a FAIR geological management solution and apply several layers to make 3d models easily accessible.

Several glacial ice advances shaped the present-day morphology of central Europe during the Quaternary. Two Pleistocene glaciations, the Elsterian and the Saalian stages, advanced as far as the north-eastern part of the onshore Netherlands. Remains of these glacial advances and retreats are deep erosional glacial valleys of the Elsterian glaciation and till sheets, glacio-tectonic ridges and glacial basins assigned to the Saalian complex.

In this study, we present the effects of sequential loading and unloading of ice sheets on the temperature distribution and rock properties of the subsurface using 3D basin and petroleum systems modelling in the northeast Netherlands. A 3D basin and petroleum systems model was set up, incorporating the Neogene to Quaternary Upper North Sea Group down to the Carboniferous Limestone Group, was used and extended to incorporate sequential loading and unloading of ice sheets in the Pleistocene.

Subsurface temperatures are decreased due to low ground and ice sheet base temperatures, with minimum temperatures observed at the beginning of a glacial stage. During an ice sheet coverage, the subsidence caused by loading leads to an increase in temperatures, therefore counteracting a low ice sheet base temperatures. Generally, a lower geothermal gradient is observed in the upper layers of the 3D model. Pore pressures build up during glacials caused by extra loading and then retreat to a pre-loading state with time, depending on the strength of ice loading, the depth of the layer, as well as the rock properties of the overburden.

The La Baja Guajira Basin (LBGB) is the primary gas-producing region of Colombia and represents South America's northernmost prolongation. This study presents an analysis of regional 2D-seismic reflection data of LBGB integrated with borehole and gravity information. The deepest basement in the study area occurs in the northwestern offshore. This depocenter is oriented NW-SE. In the basin, four fault groups occur: 1) NW-SE-striking basement normal faults; 2) strike-slip faults; 3) inverted normal faults, and 4) local thrust faults. Prominent bottom simulating reflectors (BSRs) are present in the NW deep-water areas.

2D gravity modelling was used to comprehend the basin's geometry and basement type. It indicates that the crust under LBGB is best simulated with rocks of continental nature. 1D petroleum system modelling was applied to reconstruct and evaluate the basin's burial and thermal history. Modelling results show that the study area experienced two episodes of rapid tectonic subsidence (lower Middle Miocene, Late Miocene). During the Lower and Middle Miocene, sediment input into the LBGB was from east to west. In the Late Miocene, the Andean uplift provided an additional and significant sediments contribution from the south. A period of erosion due to uplift is evident in the northern area between the uppermost Middle and Upper Miocene. From the Pliocene to recent, relative tectonic quiescence is observed. Sediments in well Mero-1 (southern offshore) were subjected to high temperatures causing Middle Miocene source rocks to reach maturation indicated by 0.69 %VRr values; however, greater depths and temperatures are required for hydrocarbon generation.

After implementation of the Repository Site Selection Act (StandAG) in 2017, the Federal Company for Radioactive Waste Disposal mbH (BGE mbH), as the German waste-management organization, started the site-selection procedure for a nuclear repository for high-level radioactive waste in Germany. On the way towards the repository site with the best possible safety, the site-selection procedure is required to be a participatory, transparent, learning and self-questioning process based on scientific expertise. With the Sub-areas Interim Report published in 2020, first results were presented, outlining sub-areas with favorable geological conditions in preparation for defining the site regions for surface exploration. The identified 90 sub-areas with favorable geological conditions cover approximately 54% of the area of Germany. Currently, one of the main tasks in the site selection procedure is to conduct the representative preliminary safety assessments for each sub-area.

Apart from the technical descriptions of the repository system, the geoscientific characterization and interpretation (Geosynthesis) of the host rock, the overburden and the geological processes serve as a basis for the safety assessment. The main character of the Geosynthesis is therefore to compile all geoscientific information, relevant to the safety of a repository. Additionally, we describe how the Geosynthesis could be used to identify potentially suitable areas within large sub-areas. These areas with the most favourable geological conditions will then be evaluated in more detail during the representative preliminary safety assessments.

Ultramafic-hosted mineralized systems commonly form massive sulphides at the seafloor which are enriched in base (Cu, Zn, Ni), critical (Co) and precious (Au, Ag) metals. In present-day settings, the limited conditions of observation at the seafloor prevents a complete understanding of these hydrothermal systems, especially concerning deep hydrothermal processes. A way to unravel deep hydrothermal processes that occur in these systems is to focus on fossil analogues preserved on-land which noticeably well crop out in mountain belts.

We adopted this strategy here and focused on a mineralized system preserved in the Platta nappe (SE Switzerland), a remnant of the Jurassic opening of the Alpine Tethys Ocean. The geometry and petrographic assemblages of the hydrothermal system, previously established, served as a base for the present study. We performed a geochemical tracing both on whole rocks and in-situ metal-bearing phases (sulphides and oxides) sampled at three distinct structural positions of the hydrothermal system. Among the geochemical tracers, Co, Ni and Se appear as good proxies to constrain hydrothermal processes. Indeed, at given structural position, the Co/Ni ratio increases in the most mineralized and altered sample suggesting this ratio is linked to the intensity of hydrothermal alteration. Also, towards the top of the system, a general trend showing respective decrease and increase of the Co/Ni ratio and of the Se content in metal-bearing phases was observed. The evolution of these geochemical tracers together with petrographic evidences supports a genetic model for the Marmorera-Cotschen hydrothermal system involving hydrothermal fluid progressively mixing with seawater.

Volcanogenic massive sulfide (VMS) deposits associated with mafic-ultramafic rocks show strong structural control and are located at or in the vicinity of low angle detachment faults such as oceanic core complexes (OCC) in mid-ocean ridge environments. These ultramafic VMS deposits are variably enriched in precious (Au-Ag) critical (Co) and the base metals Cu, Zn, and Ni but the source of the metals remains poorly known. The Troodos ophiolite, Cyprus, and the ODP Hole 735B on the Atlantis Bank are investigated to better characterize the source of metals and the deposit genesis. The ODP Hole 735B recovers gabbroic rocks down to 1508 meters below seafloor (mbsf) and shows evidence for high temperature hydrothermal alteration in the upper 250 mbsf. There the rocks are significantly depleted in Cu and S and primary magmatic sulfides are absent, implying efficient metal mobilization. Similarly, the Troodos ophiolite shows evidences for relics of OCC with seafloor-related high temperature hydrothermal alteration and associated massive sulfide mineralizations. Within the western Limassol Forest complex in the Troodos ophiolite, the Dhierna main shear zone separates serpentinized ultramafic rocks from sheeted dykes. Here, massive sulfide mineralizations enriched in As, Au, Co, Cu and Ni are observed and are characterized by pyrrhotite, pentlandite, chalcopyrite, cubanite and cobaltite. Additionally concentrations of Cu, Zn, Ni and Co in the peridotites decrease with increasing serpentinization towards the detachment fault also implying metal mobilization during hydrothermal alteration along the detachment fault.

With the establishment of the Research Center of Post-Mining (FZN) at the Technische Hochschule Georg Agricola University in Bochum in 2015, the development of an extensive archive for the systematic collection and evaluation of all post-mining related information began. In addition to the current collection of more than 4500 books and journals, over 1000 maps, as well as slides, photographs and lecture notes, a Thesaurus Post-Mining is currently being created.

The combination of historic data and modern geomonitoring techniques such as remote sensing via satellite and unmanned aerial systems, allows the contemporary handling of post-mining issues. Based in concepts of various mining companies an adjusted approach is currently developed to integrate the variety of different datasets within a spatial data infrastructure (SDI). All this information not only supports the researchers of the FZN in their work, but also creates transparency in dealing with the legacy of mining and its significance for the present and the orientation towards a more sustainable future in post-mining regions. The goal is therefore not only the ongoing digitization of existing materials, but also the creation of an open-access database on the subject of post-mining and the establishment of a server-based spatial data infrastructure for internal and external users. In the long run, this step will ensure a transdisciplinary and inter-institutional evaluation of spatial data, while the research results as well as the already existing historical information can be made easily accessible to the public within the framework of the EU INSPIRE directive.

Fluid-mediated mass transfer in subduction zones is crucial for chemical cycling on Earth. Particularly little is, however, known about such processes at shallow subduction levels.

We used thermodynamic models to reproduce the metamorphic history of ocean island basalt (OIB) clasts recovered from the Mariana forearc during IODP Expedition 366. The OIBs were subducted to ~30 km depth, metamorphosed/metasomatized, and subsequently recycled to the seafloor via mud volcanism (Fryer et al., 2020). The rocks exhibit K₂O contents (median = 4.6 wt.%) and H₂O (median = 5.3 wt.%) much higher than OIBs situated on the Pacific plate (Deng et al., 2021), suggesting that these have been added during subduction. This interpretation is in line with the presence of abundant phengite in the samples. Additionally, mass balance calculations point to the addition of SiO₂, and high Cs, Rb, Th, and U concentrations imply an uptake whereas low Ba and Sr contents indicate the removal of trace elements.

We show that the metasomatic change in composition and the formation of phengite can be explained by (i) the dehydration of altered oceanic crust releasing K₂O-rich fluids and (ii) the subsequent reaction of such fluids with OIB. These processes are predicted to initiate at temperatures of <200°C and pressures of <5 kbar.

Our study provides direct evidence for fluid–rock interactions and metasomatism in an active subduction zone. We demonstrate that mass transfer from subducted oceanic crust initiates at low pressure/temperature conditions. Subducted volcanics can hence undergo significant compositional changes even at shallow depths.

The panalpine project "DOVE" (Drilling Overdeepened Alpine Valleys), co-funded by the International Continental Scientific Drilling Program (ICDP), is drilling a series of overdeepened glacial troughs around the Alps that were formed by subglacial erosion during past glaciations.

In the northeastern section of the DOVE project, we (re)investigate the inneralpine basin of Bad Aussee (Traun glacier area, Austria), the subalpine basin of the Salzach Foreland glacier (Neusillersdorf, Bavaria), and the tongue basin area of the Pleistocene Isar-Loisach-Foreland glaciers (Schäftlarn). Depths of the inneralpine glacial erosion below Bad Aussee reach down to –400 m below sea level (the level of the Dead Sea in the Levant, the lowest part of today’s surface topography on Earth). 880 m of core material have been drilled into the basin and will be reinvestigated and physically dated by luminescence and cosmogenic isotopes.

In Neusillersdorf (Bavaria), we continue to study the basin infill of a branch basin of the Salzach Foreland glacier. We know from former dating attempts that sediments from the penultimate glaciation and older are available in the basin.

Finally, the sequence in former tongue basin area of the Isar Loisach Foreland glacier area, close to Munich, offers about 100 m of lake sediments, which are interpreted to contain sediments from Middle Pleistocene glaciations.

All available cores will be studied with state-of-the-art tools and methods in modern sedimentology and dating technics. Especially the combined investigation and interpretation of several drillholes will offer the opportunity to develop a modern reconstruction of past (Eastern) Alpine glacial environments.

The panalpine project "DOVE" (Drilling Overdeepened Alpine Valleys), co-funded by the International Continental Scientific Drilling Program (ICDP), is drilling a series of overdeepened glacial troughs around the Alps that were formed by subglacial erosion during past glaciations. The sedimentary fill of these troughs, consisting of multiple stacked and nested glacial sequences, provide the best archives of when and where glaciers reached the Alpine forelands. The combined data from all DOVE sites, comprising synchronous or asynchronous ice advances and ice extents in the different regions, will eventually provide a critical database to evaluate the various patterns in glacial-interglacial paleoclimates and landscape evolution back to the Mid-Pleistocene.

The Tannwald Basin forms a distal, overdeepened part of the Rhine glacial landscape, ca. 50 km north of Lake Constance, and has a maximum depth of 240 m. Core and flush drilling on the western flank of the basin began in April 2021 and reached the bedrock, i.e. top Tertiary Molasse, at a depth of 154 m. The glacial basin is filled by 100 m-thick fine clastics of the Dietmanns Formation (Hosskirchian – Rissian age). This is overlain by 42 m coarse clastics of the Illmensee Formation (Rissian - Wurmian age). We aim to chronologically date the sediments using borehole and core geophysics, OSL, pollen, and noble gases from pore water. Together with detailed sedimentology, these data will be used to constrain the glacial history of the basin. We show the preliminary results of the flush and core drilling, together with the borehole geophysics.

The panalpine project "DOVE" (Drilling Overdeepened Alpine Valleys), co-funded by the International Continental Scientific Drilling Program (ICDP), is drilling a series of overdeepened glacial troughs around the Alps that were formed by subglacial erosion during past glaciations. The sedimentary fill of these troughs, consisting of multiple stacked and nested glacial sequences, provides the best archives of when and where glaciers reached the Alpine forelands. The combined data from all DOVE sites comprising synchronous or asynchronous ice advances and ice extents in the different regions, will eventually provide a critical database to evaluate the various patterns in glacial-interglacial paleoclimates and landscape evolution back to the Mid-Pleistocene.

One of the DOVE sites drilled the overdeepened Basadingen Trough, located in Northern Switzerland, within the extents of several Middle-Late Pleistocene foreland glaciations of a lobe of the Rheine Glacier. The trough is a narrow, ca. 250-300 m deep structure that runs SSE-NNW, forming a so-far poorly understood, old overdeepened valley system that connected the present-day Thur Valley with the Rhine Valley – a connection that does not exist in the present surface morphology and that was probably only active during the Middle Pleistocene. New high-resolution 2-D seismic displays a detailed seismic stratigraphy with several depositional sequences, indicating that the valley fill consists of deposits from multiple glaciations, making the Basadingen Trough an ideal target for DOVE. We aim to establish a chronostratigraphic and sedimentological model to identify and understand the older glaciations that affected the Basadingen Trough and the Northern Alpine foreland in general.

The panalpine project "DOVE" (Drilling Overdeepened Alpine Valleys), co-funded by the International Continental Scientific Drilling Program (ICDP), is drilling a series of overdeepened glacial troughs around the Alps that were formed by subglacial erosion during past glaciations. The sedimentary fill of these troughs, consisting of multiple stacked and nested glacial sequences, provides the best archives of when and where glaciers reached the Alpine forelands. The combined data from all DOVE sites comprising synchronous or asynchronous ice advances and ice extents in the different regions, will eventually provide a critical database to evaluate the various patterns in glacial-interglacial paleoclimates and landscape evolution back to the Mid-Pleistocene.

In this context, we accomplished several seismic surveys at the Tannwald Basin and Basadingen Valley as well as the Lienz Basin. Deploying small-scale vibratory sources in vertical and horizontal orientations, we examined both P- and S-wave reflection imaging. We were able to image (1) the bedrock topography and (2) the interior of overdeepened valleys in high resolution in all investigated sites. Especially, the sedimentary succession and thickness of the deposits vary in detail across the sites. Even the infills of valleys in the same catchment area differ significantly (e.g. Tannwald Basin and Basadingen Valley in the Rhine Glacier arena). Nonetheless, foreland and intra-mountainous valleys show the same overall structure for each accumulation cycle (more or less from bottom to top: basal till, basin fines, fluvial deposits). As conclusion, a detailed seismic study of each overdeepened valley is mandatory for a comprehensive understanding of overdeepened structures.

Restricted basins, such as the Baltic Sea, are particularly affected by global warming, which leads to intensifying stratification, severe oxygen depletion and increasing water temperatures. This, in turn, results in significant and lasting ecosystem alterations. Sediment cores recovered during IODP Expedition 347 allow reconstructing such changes. We analysed Holocene sediments from the Landsort Deep (IODP Site M0063) using combined palynological and biogeochemical approaches to reconstruct palaeoclimate variations as well as ecosystem changes and to identify anthropogenic influences. Comparison of pollen data with organic-walled dinoflagellate cysts and other palynomorphs provides a direct land-sea comparison, while increasing palynomorph concentrations are indicative for dysoxic conditions and better preservation. Our results indicate particularly warm conditions (based on TEX₈₆) that are paralleled by high primary productivity (high TOC) and increased anoxia (low pristane/phytane ratios) around the Holocene Thermal Maximum (~7 to 5 kyr BP), Medieval Climate Optimum (~1 kyr BP) and Modern Hypoxic Period (since ~1950). For the late to middle Holocene (~7 to ~4 kyr BP), our data imply a decreasing brackish-marine influence until 4 to 3 kyr BP, accompanied by diminished aquatic primary productivity indicated by declining abundances of dinoflagellate cysts and an increase of the terrestrial vs. aquatic ratio (TAR_HC). Our data do not reveal equally strong terrestrial ecosystem changes until the past ca. 1000 years, which witnessed increased agricultural activity, implied by higher abundances of rye pollen as well as probably anthropogenically induced deforestation, implied by a relative decrease in non-saccate tree pollen and increase in non-arboreal pollen.

Understanding past variability and forcing of the Indian Summer Monsoon (ISM) is essential for better anticipating its behaviour under future climate change scenarios and the resulting consequences for the subsistence of a large part of the world’s population. However, long-term high-resolution proxy records of terrestrial hydroclimate variability from the ISM core zone are still relatively scarce. To reconstruct ISM variability and associated vegetation changes in northern India during the last ~75 kyr, we analysed the stable hydrogen and carbon isotope composition (δD, δ¹³C) of long-chain n-alkanes (n-C₂₉, n-C₃₁) from higher terrestrial plants that are preserved in marine sediments from IODP Site U1446 in the northwestern Bay of Bengal. Being located within the reach of several large rivers, this site is characterized by high riverine input of terrestrial organic matter and thus ideal for establishing representative records of past hydroclimate and vegetation changes on the northern Indian subcontinent. The obtained δD data reveal a stepwise ISM intensification at the last glacial-interglacial transition but also several distinct centennial- to millennial-scale reductions in ISM intensity during the last glacial period. These so-called Weak Monsoon Intervals (WMIs) occurred parallel to cold events in the North Atlantic realm, e.g. during Heinrich events H1, H2, H4, H5 and H6, pointing at a close hemisphere-scale climatic teleconnection between the North Atlantic and Asia. In contrast, hydroclimate-driven changes in vegetation composition during the WMIs – reflected by the δ¹³C data – were only very subtle, possibly reflecting a partial resilience of the vegetation during the last glacial period.