Vegetation cover poses a significant challenge in geological surveys. Utilizing plant chemistry to detect underlying geological features offers a non-invasive exploration tool. Here, we employ a novel approach in biogeochemical data analysis to distinguish between mineral deposits and bedrock void of mineralization. Different plant species and tissues exhibit distinct element compositions in a multivariate hyperspace, making direct comparisons in terms of absolute concentrations challenging. Our approach aims to overcome this traditional constraint by analyzing biogeochemical datasets irrespective of the specific species and tissue collected, as we will account for the physiological variations through data preprocessing. We use principles of compositional data analysis to transform biogeochemical datasets, enabling comparability across different sample materials and other plant datasets.

The corrected biogeochemical dataset for the sample type was analyzed using Linear Discriminant Analysis to identify element associations indicative of differences between samples collected over mineralized bedrock and those from rocks void of mineralization (barren). Results show differences in group means between samples sourced from pillow basalts and mafic rocks compared to their mineralized counterparts, distinguishing between mineralized and mineralization-free samples. For example, when comparing element ratios of Cu, Ca, and Rb to P and Sr, differentiation is observed across six distinct plant materials between barren pillow lavas and the corresponding mineralized bedrock.

The Pohjanmaa Belt in western Finland hosts orogenic Au deposits with enrichment in base metals, such as the Jouhineva Cu-Co-Au-Ag deposit (0.448 Mt at 0.811% Cu, 0.182% Co, 0.88 ppm Au, and 7.864 ppm Ag measured reserves). It is located 3 km NW of the Au-only Huhta occurrence along the same NNW-trending fault. We test if the different metal association in both deposits is related to temporally and structurally different mineralization events. Four deformation events are distinguished: D₁ formed a now EW- and NW-trending S₁, which is transposed during subsequent deformation; D₂ folded S₁ into a NW-SE to NNW-SSE trending S₂ crenulation cleavage; D₃ refolded S₂ into close to isoclinal folds and generated a NNW-SSE trending, axial planar S₃; D₄ formed a centimeter-spaced, EW-trending S₄ foliation. Huhta hosts syn-D₃ Lö-Apy-Au-Qtz veins with multiple stages of sulfide, arsenide, and sulfarsenide mineralization. Jouhineva hosts syn-D₃ Apy-Au-Ccp-Qtz and syn-D₄ Ccp-Au-Qtz veins. Titanite U-Pb and structural data indicate synchronous formation of Lö-Apy-Au-Qtz veins in Huhta and Apy-Au-Ccp-Qtz veins in Jouhineva at 1850-1820 Ma during D₃. Thus, the different mineralogy and metal endowments formed during the same tectonic event during the Svecofennian Orogeny. Only Jouhineva hosts additional Cu-Au mineralization that formed later during the retrograde evolution. The different metal association in both occurrences may be explained by different metal and fluid sources and compartmentalized fluid migration, distinct mineralization events during the 30 m.y. evolution that cannot be resolved by titanite geochronology, or different precipitation mechanisms although host rocks and PT conditions are similar.

The Gorno mining district is an example of Mississippi Valley-type (MVT) deposits in the Italian Orobic Alps. Spanning an area of ~100 km², it consists of stratabound Zn-Pb-Ag (± fluorite ± barite) mineralization hosted in a lower Carnian stratigraphic succession. Despite Vedra Metals S.r.l.´s acquisition of the exploration license for the deposits has reignited an economic interest, an updated metallogenic model has yet to be developed.

In the carbonate host rocks at Gorno, a complex series of dolomitization, silicification, brecciation, dissolution, and cementation occurred. Microthermometry of primary fluid inclusions in sphalerite and fluorite, alongside sphalerite trace-element geothermometry, indicates formation temperatures ranging from 80 to 140 °C (mean value: ~100 °C). Moreover, fluid inclusion microthermometry and micro-Raman spectroscopy document the involvement of high-salinity brines (up to ~25 eq.wt% NaCl) and gaseous hydrocarbons (e.g. CH₄) in ore deposition. Isotopic signatures from ore-related carbonates for carbon (0.5 to 2.5 ‰ PDB), oxygen (-6.6 to -12.1 ‰ PDB), and strontium (0.70840-0.70943) indicate that the ore fluid was likely seawater modified through interaction with the underlying Permian clastic sediments and/or with the metamorphic basement.

The presence of sulfide bodies in association with organic-rich shales implies a notable role of organic carbon in ore deposition. Organic matter and associated hydrocarbons likely served as reactive barriers, leading to the reduction of the ore fluid and initiating the precipitation of sulfide minerals.

Efficient transfer of S and chalcophile metals through the Earth’s crust in arc systems is paramount for the formation of large magmatic-hydrothermal ore deposits and can strongly affect the Earth’s climate. The formation of sulfide-volatile compound drops has been recognized as a potential key mechanism for such transfer but their fate during dynamic arc magmatism remains cryptic. We report evidence of compound drops preserved in the active Christiana-Santorini-Kolumbo volcanic field. The observed compound drops are micrometric sulfide blebs associated with vesicles trapped within silicate phenocrysts. The compound drops accumulate and coalesce at mafic-felsic melt interfaces where larger sulfide ovoids form. These ovoids are subsequently oxidized to magnetite during sulfide-volatile interaction. Comparison of metal concentrations between the sulfide phases and magnetite allows for determination of element mobility during oxidation. The formation and evolution of compound drops is an efficient mechanism for transferring S and chalcophile metals into shallow magmatic-hydrothermal arc systems.

There is still no consensus in the literature concerning the most critical processes for rare earth elements (REE) enrichment in carbonatite rocks. One-third of alkaline‑carbonatite complexes are associated with ultrabasic and basic rocks. Some basic rocks contain similarly high concentrations of LREE as carbonatites where perovskite [CaTiO3] is responsible for this enrichment. Carbonatites form later than ultrabasic and basic rocks, and carbonate melt penetrates into silicate rocks and reacts with them. The reaction was named “antiskarn reaction”. Until now there is no detailed study on whether perovskite from pyroxenites can become a source for REE enrichment of carbonatite melt during antiskarn reactions.

We studied three ultrabasic-alkaline carbonatite complexes from the Kola Alkaline Province (Russia) to focus on the comparison of REE contents from pyroxenites and carbonatites and the fate of perovskite. Ultrabasic/basic rocks and carbonatites show the same broad range of REE contents. In most analyzed pyroxenites, perovskite is the main REE carrier mineral. For carbonatites/phoscorites, apatite and calcite are the minerals that control rocks' REE enrichment. Several samples show considerable variations of REE concentrations related to carbonatite infiltration, sometimes even at a very low local scale (mm²). If perovskite was present it was replaced near the carbonatite melt by titanite that has much lower REE contents. Calcites and apatites from the infiltrated carbonatite are highly enriched in LREE but show large local element variations. Thus, we propose that LREE liberated by the perovskite replacement can be dissolved in the carbonatite melt and transferred to its crystallizing minerals (calcite, apatite).

The Kalahari Manganese Field (KMF) of the Northern Cape Province of South Africa hosts about 74% of all known minable manganese ores globally. It represents the largest known land-based Mn deposit. More than 90% of the resource can be best described as mangano-lutite, e.g., a microcrystalline, ovoid-rich, finely laminated chemo-sedimentary rock containing between 30-40 wt.% Mn. Despite its great geological age (2.42 Ga), the mangano-lutite and its surrounding volcano-sedimentary host rock succession (Transvaal Supergroup) have not experienced any significant metamorphic overprint. Owing to its exceptionally fine-grain size and unusual composition, the mineral paragenesis and diagenetic microfabric of the mangano-lutites remain poorly documented. This contribution aims to show that modern SEM-EDS-based image analysis platforms, such as the TESCAN TIMA instrument, can not only provide quantitative mineralogical data, but can also reveal unprecedented insight into diagenetic microfabric and a complex succession of mineral assemblages in the mangano-lutites. The instrumental approach developed for this application is of extreme industrial and economic importance due to increasingly complex ores and a mandatory need to beneficiate by-products in the shift to sustainable mining. It can be easily transferred to other applications on fine-grained rocks (e.g. carbonate mudstones, fault gouges), ores (e.g. nickel laterites, bauxites) or anthropogenic solid materials (e.g. tailings, flue dusts).

Li extraction as a byproduct in deep geothermal power plants is a promising option for the upcoming challenges in Li supply chains. In Germany, regions in the North German Basin and Upper Rhine Valley are suitable for these kind of operations as Li concentrations reach up to 375 mg/l in deep formation waters [1]. To provide further insights on the occurrence of Li in deep formation waters, its geochemical behavior and possible release reactions of Li from mineral dissolution or surface exchange in deep geothermal systems, experiments at in situ conditions (100 – 160 °C, 370 bar) with drill core material of reservoirs rock were conducted in Au capsule and flexible Dickson-type Au-Ti cells. In addition, rock samples were investigated by petrographic and geochemical analysis in order to identify the main Li-bearing mineral phases and their respective Li concentrations. Results of fs-LA-ICP-MS measurements identified chlorite and biotite to be the main Li-bearing minerals, but low Li concentrations were also found in multiple other mineral phases. Batch experiments revealed that a near-equilibrium concentrations for Li are attained rapidly in 3 to 6 days of experimental run time.

[1] Alms, K., Jagert, F., Blömer, J., & Gehrke, I. (2022). Co-production of geothermal energy and lithium from geothermal waters. In European Congress.

Der Terminus „kritische Rohstoffe“ erlangte als Gegenstand der „Mitteilung der Kommission an das Europäische Parlament, den Rat, den Europäischen Wirtschafts- und Sozialausschuss und den Ausschuss der Regionen – Grundstoffmärkte und Rohstoffe: Herausforderungen und Lösungsansätze“ in Europa 2011 erstmals größere öffentliche Aufmerksamkeit.

Eine damals 14 Positionen umfassende Liste wurde seitdem mehrfach erweitert und umfasst derzeit 34 Rohstoffe. Ergänzend wurden im Jahr 2023 „strategische Rohstoffe“ definiert, welche zum größten Teil „kritische Rohstoffe“ beinhalten.

In diesem Vortrag wird der Frage nachgegangen, inwieweit die derzeit bekannten Rohstoffvorkommen Sachsens auch die von der EU definierten kritischen Rohstoffe beinhalten. Weiterhin werden exemplarisch ausgewählte Herausforderungen betrachtet, welche einen entscheidenden Faktor darstellen, ob derartige sächsische Vorkommen (z.B. von Cu, In, REE etc.) auch tatsächlich kurzfristig zur Sicherung der Rohstoffversorgung genutzt werden können.

Für die aktuell funktionierende ökonomische Basis Sachsens ist eine sichere Versorgung mit wesentlich mehr Rohstoffen erforderlich, als derzeit in Form der EU-Liste kritischer Rohstoffe im Fokus der Aufmerksamkeit stehen. Dazu gehören beispielsweise Baurohstoffe. Aber auch die stetige Erweiterung der als „kritisch“ definierten Rohstoffe lässt es sinnvoll erscheinen, für eine langfristige Sicherung der Rohstoffbasis weit vorausschauende Planungen vorzunehmen und nicht zu warten, bis ein Rohstoff offiziell als kritisch erklärt wird. Demgemäß sollten auch derzeit noch als unkritisch betrachtete Rohstoffe bereits jetzt vorsorgend erkundet und zumindest planerisch für eine eventuelle spätere bergbauliche Gewinnung gesichert werden.

Parallel zu diesen Bemühungen gewinnt die Beantwortung der Frage an Aktualität, inwieweit das derzeit prognostizierte weitere Wachstum des Bedarfes an Primärrohstoffen mit einer nachhaltigen Existenz des globalen Ökosystems Erde vereinbar ist.

The Sora Ni-Cu-(PGE) sulfide mineralization is associated with a ~400 x 40 m dike-shaped gabbroic intrusion that is exposed in a dimension stone quarry about 5 km SW of Bautzen (Saxony/Germany). The Sora dike is one of several Ni-Cu-(PGE) sulfide-bearing gabbroic intrusions (e.g. Angstberg, Dahrener Berg, Sohland-Rožany, Kunratice) that occur in the Lausitz and Šluknov region on both sides of the German-Czech border. The gabbroic intrusions are part of interconnected magmatic plumbing systems that intruded Cadomian granodiorites of the Lausitz Block (northern Bohemian Massif) in the Middle to Late Devonian (~390–370 Ma). The Sora dike represents a composite intrusion with olivine gabbronorite, gabbro and diorite as major lithologies. The magmatic sulfide mineralization comprises blebby disseminated sulfides in the olivine gabbronorite and variable-shaped massive sulfide patches that locally occur along both contacts of the gabbroic dike to the granodioritic country rock. Subordinately, larger sulfide patches are also hosted by pegmatitic albite-amphibole-enriched schlieren within the olivine gabbronoritic part of the intrusion. The mineralization represents a typical magmatic sulfide mineral paragenesis with dominating pyrrhotite, pentlandite and chalcopyrite, variable amounts of Fe-Ti oxides and trace amounts of PGE-, Au-, Ag- and TABS-bearing minerals. The PGE mineral assemblage is dominated by Pd melonite. The magmatic sulfides are characterized by relatively high Ni tenors (metal content in 100 % sulfide) and variable Cu, Co, Pt, Pd and Au tenors (~0.3–9.0 wt.% Ni, ~0.2–7.0 wt.% Cu, ~0.1–0.4 wt.% Co, ~20–1210 ppb Pt, ~40–1400 ppb Pd and ~20–1230 ppb Au).

The eastern part of the Erzgebirge region hosts an exceptional abundance of greisen- and vein-hosted Li-Sn-(W) deposits (e.g., the Zinnwald-Cínovec district), located across the eastern part of Germany and the northwestern part of Czech Republic. However, only a few of those deposits have been reliably age-dated (e.g., the Sadisdorf district), leaving the timing of hydrothermal mineralization on the regional scale widely unconstrained.

Here, we report new U-Pb LA-ICP-MS ages of cassiterite from Li-Sn-(W) mineralization at Zinnwald, Altenberg, Niederpöbel, Schmiedeberg, Bärenfels, Lauenstein and Krupka. The new ages of the different localities span between 315.1±3.7/4.4 and 306.6±1.5/3.5 Ma. Therefore, greisen- and vein-hosted cassiterite ages constrain hydrothermal mineralization's timing, on a regional scale, to a narrow time window of ~10 Ma years and are significantly younger than previously proposed ages between 325 and 318 Ma. The new ages are consistent with recent zircon ages of (sub-)volcanic rhyolite units (315 to 313 Ma), which are the host rocks of some of the Li-Sn-(W) granites. Greisen formation and associated cassiterite crystallization thus temporally coincides with the formation of the 315-310 Ma ring dykes linked to the collapse of the Altenberg-Teplice caldera.

The Erzgebirge hosts numerous stratiform tin occurrences, which are located along the same structural level within the Variscan orogenic belt. One of these tin deposits, the Bockau tin occurrence, is located in the area between Aue-Bad Schlema – Bockau – Zschorlau with alternating sequences of quartzite and metaschist. This layered sequence records geochemical signatures of intensely weathered sedimentary rocks. Their protolith probably formed during the Ordovician at the passive continental margin of Gondwana. The mineral assemblage consists of quartz + biotite + garnet + muscovite + andalusite + chlorite + cassiterite + accessory-phases. Cassiterite grains are concentrated in layers concordant to the foliation plane, occur as inclusions within foliation parallel biotite, and are overgrown by garnet blasts. These textures indicate that cassiterite has been present prior to the Variscan continental collision. The frequent occurrence of cassiterite also correlates with the high Sn-contents of the tin bearing metasediments (mainly ranging from < 50 to 2000 ppm). Different methods of conventional thermobarometry and pseudosection modelling were applied to reconstruct the regional metamorphic overprint at 550 ± 50 °C / 8 - 9 kbar and a subsequent thermal peak of at least 600 °C. These results are characteristic for the regional metamorphic conditions reached along the north-western border of the Erzgebirge, though the maximum temperatures reached are slightly higher than previously thought. There is a lack of evidence for a post-magmatic / metasomatic history of the Bockau tin occurrence by the applied methods and petrographic observations.

The Werra Potash District is located on the border of the federal states of Thuringia and Hesse. Mining has taken place in this area for more than 125 years. The mined area is larger than the city of Munich. The two potash seams in this area, called the Thuringia and Hesse Potash Seams, are generally between 3 and 5 meters thick and are located in the Werra Salt, which is 300 m thick. There are two active mines, Hattorf-Wintershall and Unterbreizbach, in which approximately 19 million tonnes of raw salt are mined annually. Exploration is very important for mining in terms of being able to forecast and obtain information about the thickness and mineralogy of the potash seams, the presence of basalt dikes and areas with hydrogeological risks or gas hazard areas.

In general, exploration can be divided into two categories: surface exploration and underground exploration.

Surface exploration: there are many surface drill holes and shafts from the last century that allow conclusions to be drawn about the geology and mineralogy of the potash seams and the overburden.

In addition, numerous geophysical measurements are carried out like seismic surveying, gravimetric surveying and geomagnetic measurements.

Underground exploration: in the two active mines, underground drilling with a length of more than 80 km per year is carried out. All underground drill holes are measured using 3D radar. All geological data are processed in a 3D geological model, which enables forecasts for mine planning, resource estimation as well as geomechanical modeling.

In-mine seismics provide a better resolution and spatial coverage than surface exploration methods such as 2D or 3D seismics, enhancing the exploration around underground facilities. Over the past decades, seismic exploration techniques have been developed to address challenges in exploring ahead and around tunnels and mines. Methods such as reflection seismics and tomography are applied, taking into account the constraints on resolution and exploration range due to the distribution, accessibility, and shape of in-ground cavities.

The major challenges for the application of underground seismic exploration include avoiding cost-intensive downtimes of construction and production, as well as minimizing risks to underground facilities for safety reasons. The Integrated Seismic Imaging System (ISIS) largely integrates seismic exploration into the workflow of tunnel construction. ISIS has been improved to 3D underground seismics within the Helmholtz Innovation Lab 3D-Underground Seismics. For a detailed seismic exploration, seismic sources and receivers are used in all accessible underground spaces. The exploration capabilities were enhanced with a seismic borehole tool for exploration ahead, a borehole receiver chain, and a borehole source in exploration boreholes.

With efficient impact hammers or magnetostrictive vibrators as sources and three-component receivers, our 3D underground seismics can resolve and image 3D structures in underground with reconnaissance depths up to several hundred meters and resolutions of dm to m. Especially for exploration in clay-bearing salt reservoirs 3D underground seismics is an alternative to the established GPR. We present the components of our 3D-underground seismics and discuss their applications based on case studies in various salt mines.

We explore this question using the example of salt structures in Northern Germany. The salt mines in the North German basin are among the best explored in the world. The question now arises as to whether findings on the internal structure of these salt structures also allow conclusions to be drawn about previously unexplored diapirs. BGR worked on the crucial question posed by BGE on the prediction of homogeneous salt volumes in saline rocks. However, improvements in the prognosis could also support the exploration and possible future economic use (as storage caverns) of underexplored salt structures, for example in the German North Sea. Our method is based on the definition of several basin-wide assessable proxies, which suggest an influence on the internal structure and its variability with regard to the utilization of the salt structure. Furthermore, additional findings on genesis, kinematics or the detailed internal structure are discussed which cannot be directly transferred into a basin-wide proxy but can contribute to the evaluation of the variability of the internal structure. Due to the wide range of influencing factors to be discussed, our presentation will focus in particular on new findings on salt tectonics from the comparison of the analyzed structures, but also on the given limitations of a prediction of the internal structure. In summary, certain types of salt structures that have passed through certain evolutionary stages indicate a higher probability of larger salt homogeneous volumes in economically exploitable depths.

Rock salt is a valuable commodity for the food and fertiliser industries. It is also used as a host for artificial underground structures, such as caverns. As part of Germany's transition to net-zero energy by 2045, rock salt caverns will continue to be needed, but they must be suitable for storing green hydrogen. Salt deposits could also provide a potential source of lithium, with German demand currently being met by imports. However, more information is required to understand the potential of rock salt deposits and to decipher their suitability.

Several stratigraphic salt horizons occur in the geological record of Schleswig-Holstein, ranging in age from the Triassic (Keuper, Muschelkalk, Bunter) to the Permian (Zechstein, Rotliegend). The economically exploited horizons are of Zechstein and Rotliegend ages and often form salt domes and walls. A special feature is the so-called "Doppelsalinare", where older Rotliegend salt is intruded into younger Zechstein salt due to rheological processes.

The aim of this study was to characterise the different salt horizons in terms of their mineralogy and geochemistry and to identify any potential lithium resources. To achieve this, rock salt samples were examined by polarised microscopy, quantitative mineralogy was determined by X-ray diffraction, while geochemistry was analysed by X-ray fluorescence and inductively coupled plasma mass spectrometry.

Our results show that each stratigraphic salt horizon is characterised by a unique Br-Cl spectrum, with lithium and other trace elements also showing distinct patterns.

Two significant potash-bearing basins occur within Central Asia. The Pricaspian Basin refers to an approximately 600 km wide (east-west) structure at the northern end of the Caspian Sea. This structure is filled with up to 4.5 km thick Permian (Kungurian and Roadian (Kazanian)) evaporite rocks and covered mainly by clastic sediments. Due to the large thickness of overlying sediments, diapirism of the salt rocks started with an initial movement phase between the late Permian and the Triassic and a later movement phase in the period between the Juraissic to the Neogene. Several hundreds of salt structure, that bring the potash salt close to the surface are known within the basin.

The Central Asian Salt Basin is a Jurassic to Early Cretaceous evaporite basin that spans across Uzbekistan, Turkmenistan, Tajikistan and Afghanistan. Occurrences of potash salts are largely confined to the Late Jurassic Gaurdak Formation, though evaporites of Paleogene age are also known. The deposition of the salt deposit is connected to the development of the Neotethys. Maximum thickness of the Gaurdak Formation is about 1,200 m with the evaporites being thickest in the vicinity of the Gissar Range. Clastic and carbonatic sedimentary rocks make up the hanging wall of the formation. The basin was divided by uplift of the Gissar range in Miocene times into the Amu Darya Basin towards the west and the Afghan-Tajik Basin to the east. Salt rocks are present at or close to the surface around the Gissar range.

The Mesoarchaean West Rand Group displays a layer-cake stratigraphy with lithostratigraphic units correlatable on a basin-wide scale. The ~5 km thick succession consists of fluvial braidplain and shelf deposits, which range from shallow inner shelf marine orthoquartzites, outer shelf argillites to starved shelf iron-formations. Three major sequences are present: Sequence I (Hospital Hill Subgroup), Sequence II (Government Subgroup) and Sequence III (Jeppestown Subgroup).

Sequence I was deposited during a period of highstand of sea-level, sequence II during a period of relative lowstand, and sequence III during a period of relative highstand coupled with high rates of sediment supply. Isopach, depofacies and palaeocurrent analyses indicate that strata in the western to northwestern parts of the basin were deposited under more proximal sedimentary conditions compared to those in the central or southeastern parts. Little relationship between the present outline of the basin and the distribution of depofacies suggests that the original sedimentary basin was significantly larger in areal extent.

Depofacies and thickness distribution, as well as synsedimentary deformation of strata, indicate that the basin was most probably of flexural tectonic origin. These findings support deposition in a wide, shallow, and rather stationary foreland basin, with an axial zone towards the west/northwest and low amplitude peripheral bulge to the east/southeast. Such shallow foreland basins, with abundant sediment bypassing, are thought to be associated with windward-facing orogenic fronts. High rates of erosion along such fold-thrust belts lead to ineffective loading and advancement of the orogenic front, as well as an oversupply of sediment.

The Bromacker Project (https://bromacker.de/) investigates the “Ursaurier” vertebrate Lagerstätte of the same name in Early Permian redbeds of the Tambach Formation. Its geologic-paleontologic subproject contributes key parameters such as paleoecology, paleoclimate, paleogeography, and depositional environments to the reconstruction of the Tambach Basin.

Two research boreholes were drilled in 2022 and 2023 to complement information from outcrops and several legacy boreholes near the Bromacker site. Forschungsbohrung (Fb) Altenbergen 01/2022, located in the northwest of the basin, cored 250 m of the Tambach Formation and terminated in the basal Bielstein Conglomerate Member. Fb Tambach-Dietharz 01/2023 in the southeast of the basin terminated at 199 m depth in the pre-Tambach Rotterode Fm. The Bielstein Conglomerate Member is correlated between both boreholes; it consists of well-rounded volcanic clasts of a braided river setting. In the Altenbergen borehole, fluvial deposits of the Tambach Sandstone Member consist of massive mudstones interbedded with laminated shale in fluvial floodplain settings interspersed with temporary ponds and paleosols; whereas this member is present as gravelly fluvial-channel sandstone facies in the Tambach-Dietharz borehole. Fluvial channel deposition is terminated by prograding alluvial fan sedimentation represented by the Finsterbergen Conglomerate Member present in both cores. The influx of fluvial sandstones bearing plutonic and metamorphic clasts, observed in both boreholes, marks the exposure of the Ruhla Crystalline Complex to the west.

Especially the Tambach Sandstone Member shows different sedimentary facies throughout the core on a distance within the basin of around 4 km, showing also a clear distinction between habitats within the Tambach Basin.

A common tool in provenance studies of clastic sedimentary rocks is the geochemical composition for identification and differentiation of potential catchment areas. However, not only source rock lithologies but also for instance sorting, alteration, leaching or new mineral formation influenced by the climate during erosion, transport and deposition or by diagenesis during burial influence the geochemical provenance signal (Augustsson et al., 2023). Therefore, the consideration of the genetic and diagenetic changes of the deposits, i.e. their development over time, plays an important role for a meaningful interpretation of geochemical data for provenance studies.

To test this, we investigate Permo-Carboniferous terrestrial sandstone and conglomerate. The units represent changing palaeogeographic and climatic conditions. In addition, the deposits underwent diagenetic changes during deep burial and partial uplift to present-day borehole depths of 1500-2500 m. We use polarization, cathodoluminescence, and scanning electron microscopy, microprobe analyses, XRD, XRF, and ICP analyzes. Initial results indicate correlations of the Chemical Index of Alteration and K₂O/Na₂O with the preservation state of detrital feldspar and the diagenetic clay minerals kaolinite and illite. Th/Sc and Y/Zr correlate with lithoclast composition (felsic versus mafic igneous and metamorphic) and the intergranular components (matrix versus cement). This allows the separation of Carboniferous and Permian samples. It is a result of changing climatic and diagenetic conditions.

Reference: Augustsson, C., Aehnelt, M., Olivarius, M., Voigt, T., Gaupp, R., & Hilse, U. (2023). Provenance from the geochemical composition of terrestrial clastic deposits-a review with case study from the intracontinental Permo-Triassic of European Pangea. Sedimentary Geology, 106496.

The Triassic Skagerrak Formation in the Central Graben of the North Sea is a fluvial-lacustrine succession that is historically difficult to subdivide in the subsurface into lithostratigraphic units, and to correlate between different wells and licence blocks. The formation consists of various sandstone members interspersed by mudstone members with relatively poor age constraints. Raman spectroscopy of heavy minerals in combination with chemostratigraphy is an effective tool to identify lithological differences and to reconstruct provenance of the individual members. The lower parts of the Skagerrak Formation (Judy Sandstone Member) are generally characterised by ultra-stable heavy mineral assemblages, indicating multi-recycling of nearby Palaeozoic cover units, while the directly underlying Bunter Sandstone additionally has several unstable mafic heavy mineral species, probably derived from local basement highs (e.g., Forties Montrose High). Up-section within the lower parts of the Joanne Sandstone Member there is a switch to more immature apatite-rich heavy mineral assemblages, likely related to a source change to Fennoscandian basement at the Norwegian margin. A mafic marker horizon within the upper Joanne Sandstone indicates input from contemporaneous volcanism at the Carnian-Norian boundary, and may represent a significant basin-wide unconformity.

The present-day hyperarid Sahara is the largest hot desert in the world, but its development in deep time is largely unknown. The inception of persistent Northern African aridification has been variously linked to the onset of Northern Hemisphere glaciation at the beginning of the Pleistocene. However, eolian bedforms and dust records, reinforced by modelling studies, indicate transient periods of aridity have started North Africa already in the latest Miocene during times of Northern Hemisphere cooling. For the globally warm Pliocene epoch intermittent aridity is suggested for the western Sahara by dust records from the Canary Islands. In contrast, onshore evidence of contemporary North African climate is missing, because of the lack of well-dated Neogene sections in the Sahara.

Here we present a thoroughly sedimentological, paleoenvironmental and geochronological investigation of the Neogene continental Wadi El Natrun Formation in the northern fringe of eastern Sahara (Wadi El Natrun, northern Egypt). We differentiate seven sedimentological facies types, each distinguished by characteristic palaeobiota. These are in an ascending order: braided river and overbank facies, which contain abundant fluvial and riparian vertebrates; a lacustrine black shale facies rich in phytoclasts; a lacustrine limestone facies with characean algae; a marine limestone facies with planktonic foraminifera and marine molluscs; a playa lake facies with a thalassosaline ostracod and gastropod fauna; an ephemeral stream facies with Skolithos and Ophiomorpha ichnofabrics; and finally an eolian dune facies with polydomic ichnofabrics.

These changes in sedimentological facies indicate the long-term temporal progression of desertification in Northern Africa well before the Quaternary.

Deep-time reconstruction of palaeoenvironments is of great importance for many geoscientific and life science disciplines. Various geoarchives provide information on ancient dust fluxes that affect climate and biodiversity and which also hold clues to palaeogeography. Furthermore, "rates" are integral to almost all related research questions, requiring the use of state-of-the-art dating techniques on various materials that act as dust traps.

Intercontinental dust fluxes, such as those from the African deserts to South America cause large-scale geo-bio interactions. Such wind-blown particles fertilise the vibrant ecosystems of the Amazon rainforrest, where the dust is rapidly metabolised or bioturbated by countless organisms. Saharan dust transported to Europe is also difficult to trace back through time, as single events rarely result in detectable deposits. This calls for alternatives to conventional drilling or outcrop studies. Datable dust archives containing detrital heavy minerals provide snapshots of dust transport in a high spatio-temporal resolution. Therefore, analyses like LA-ICP-MS U-Pb age determination on detrital zircon or SEM-EDX chemical characterisation on large numbers of individual terrestrial dust particles are applied.

However, even the most advanced techniques for exploiting new geoarchives are of limited benefit without information on the original dust sources and their availability over time. For this reason, the evolution of drainage systems through time is studied in particular, as rivers are often the primary source of desert sediments. This whole approach involves compilation and processing of large datasets, e.g. a circum-Atlantic zircon age database (N>5000, n>275000). Initial results are very encouraging and go beyond the proof-of-concept stage.

Astronomical insolation forcing is well established as the underlying metronome of Quaternary ice ages and Cenozoic climate changes. However, its effects on earlier eras (Mesozoic, Paleozoic, and pre-Cambrian) are less understood. In the first part of this presentation, I will argue that formally defining 405,000-year eccentricity cycles as chronostratigraphic units (astrochronozones) throughout the Phanerozoic eon is a crucial research goal for the next decade. Establishing a common cyclostratigraphic framework to harmonize cyclostratigraphies between key sections in Europe and North America (in particular for the Devonian) is of primary importance. The goal of defining Phanerozoic astrochronozones would enhance our understanding of how astronomical forcing has shaped Earth's climate over geologic time.

Subsequently, I will discuss several lines of evidence suggesting that Devonian oxygen deficiency was sensitive to rhythmic astronomical forcing. Nonetheless, the question of why some anoxic events were more severe than others remains unresolved. Therefore, it is increasingly important to employ cyclostratigraphy to distinguish between different climate modes of the Devonian and to improve our understanding of the role of astronomical forcing in Devonian ocean anoxic events.

Rhenish Massif and Ardennes are the type regions of the classic Gedinnian, Siegenian, and Emsian stages (and subunits) of the Lower Devonian, which are mainly defined by brachiopods. In the course of the ongoing taxonomic revision of the Rhenish Lower Devonian representatives of the phylum, numerous new biostratigraphic data have been obtained. The revised biostratigraphy includes 25 taxon range and 20 assemblage zones from the Pridoli to the Eifelian, which can be further subdivided into subzones. Although Lochkovian, Pragian, and Emsian GSSPs have long been defined elsewhere on the basis of pelagic guide fossils, the classic Ardenno-Rhenish stratigraphy is still an important reference in the Lower Devonian, e.g., for the envisaged redefinition of the basal Emsian GSSP.

The biostratigraphic utility of brachiopods is restricted both by their limited palaeogeographic distribution and their dependence on the facies. In the case of the Rhenish Lower Devonian, specific subtypes of the rhenotypic facies have to be considered (e.g., eurhenotypic, allorhenotypic and pararhenotypic facies). Nevertheless, the Rhenish brachiopods are excellent guide fossils, and thanks to close palaeobiogeographic relationships the revised biostratigraphy can be used with reservations in Western Europe and North Africa, i.e., within the boundaries of a ‘Maghrebo-European’ palaeobiogeographic unit. Here, correlations of regional brachiopod and global pelagic biostratigraphies are possible. To conclude, it can be said that the revised Lower Devonian brachiopod stratigraphy has the potential of providing a fine-scaled biochronological framework for future stratigraphic, palaeoecological, and palaeobiogeographic studies.

The super-continent Pangea was characterised by strong continentality because of climatic change from an icehouse earth during late Pennsylvanian and early Permian via an increasingly warm earth during middle–late Permian into the early Triassic super-hot house. Consequently, marine incursions, caused by the glacial cycles (cyclothems), decreased during the early Permian. Because of increasingly absent marine deposits in the Permian, the correlation of the continental deposits with marine zone-fossils (ammonoids, conodonts, fusulinids) becomes complicated. Very helpful for the correlation would be radioisotopic ages from intercalated volcanites. Unfortunately, during late early Permian, volcanism decreased in the continental Euramerica. In the middle and late Permian, no radioisotopic ages exist so far for Euramerica. Newest Late Pennsylvanian and earliest Permian radioisotopic ages based on the U-Pb CA-ID-TIMS (chemical abrasion-isotope dilution-thermal ionisation mass spectrometry) method fit well with continental and marine biostratigraphic correlations. However, some new high-precision U-Pb CA-ID-TIMS ages, especially from the Thuringian Forest Basin, conflict with the biostratigraphy and other radioisotopic ages in European basins. They are even in contrast to the climate-stratigraphy in Euramerica, particularly to the outspread of wet and, later, dry reds beds, which, of course, only provide rough interregional time markers. The question arises, what do these highly precise radioisotopic ages tell us? Are they really the decisive eruption ages or do they represent (far) older crystallisation processes in the magma chamber? In any case, we should only trust ages (and even biostratigraphic data) that are supported by cross-correlations with data from different independent stratigraphic methods.

The world’s largest ammonite, Parapuzosia (P.) seppenradensis (Landois, 1895), has fascinated the world since the discovery in 1895 of a specimen measuring 1.74 metres (m) in diameter near Seppenrade in Westfalia, Germany. Subsequent findings of this taxon have been rare. For this study (Ifrim et al., 2021), the historical specimens have been revised, and abudant material from England and Mexico was documented. It comprises 154 specimens of large (< 1 m diameter) to giant (> 1m diameter) Parapuzosia from the Santonian and lower Campanian, mostly with stratigraphical information. High-resolution integrated stratigraphy allows for precise trans-Atlantic correlation of these occurrences. The Tepeyac section in northeastern Mexico, where 66 specimens of diameters from 10 to 150 cm were found in their original layer was documented with integrated stratigraphy. With 330 ammonoids and >100 inoceramids, among other fossils, it is the section with the richest fossil record in that interval. It has become Associated Stratotype Section and Point for the base of the Campanian (Gale et al. 2023). The high- resolution correlation allows for further insight into the palaeobiology, evolution and dispersal of worlds largest ammonite

References
Gale, A., et al. 2023. The Global Boundary Stratotype Section and Point (GSSP) of the Campanian Stage at Bottaccione (Gubbio, Italy) and its Auxiliary Sections: Seaford Head (UK), Bocieniec (Poland), Postalm (Austria), Smoky Hill, Kansas (U.S.A), Tepayac (Mexico). Episodes. doi: 10.18814/epiiugs/2022/022048.
Ifrim, C. et al. 2021. Ontogeny, Evolution and palaeobiogeographic distribution of Parapuzosia (P.) seppenradensis, the world's largest ammonite. PLoS ONE 16, e0258510. doi: 10.1371/journal.pone.0258510.

After the peak warmth’s of mid-Cretaceous times, progressive climate cooling occurred during the late Cretaceous, with a global temperature decline in the order of Cenozoic cooling without signs of major and persistent glaciation. Thereby, the Maastrichtian marks a cool greenhouse period with different non-analog boundary conditions in comparison to today. Global mean temperatures, polar ice extents, regions of deep-water formation, types of vegetation, as well as patterns and variability of precipitation and evaporation were all different. Repeated multi-million-year long periods of climate cooling and warming occurred during the cool Maastrichtian greenhouse. Particularly, the latest Campanian–early Maastrichtian witnessed substantial deep-water cooling as well as a carbon cycle perturbation expressed by a long-lasting negative carbon isotope excursion. Our understanding of climate and carbon cycle dynamics is still limited for times prior 66 million years, particularly for the Campanian–Maastrichtian transition. The lack of highly resolved stratigraphy introduces severe uncertainties in the quality and interpretation of global correlation. Here we present the present state in the development of an astrochronology for the Maastrichtian stage that integrates sedimentary cyclicity, carbon isotope and magnetostratigraphy in combination with biostratigraphic events from the successions of Zumaia, Sopela, Bidart and the GSSP locality Tercis-les-Bains belonging to the Basque-Cantabrian and Aquitain basins in Spain and France. The development of a Bay of Biscay Maastrichtian record will provide new insights about the phase relation between orbital forcing and carbon cycle response, as well as temporal relations to changes in ocean chemistry, circulation and sea level, and the ecosystem response.

In recent decades, mining-related activities in the Lusatian lignite mining area have led to an extensive pyrite weathering, contributing thereby to the elevation of sulfate and iron concentrations in the groundwater and surface water.

Due to the complicated pathways of pyrite oxidation and the complex spatial distribution of the pyrite-bearing layers, it is difficult to develop a comprehensive restoration plan. Therefore, developing a quick and non-intrusive geophysical measuring technique for estimating pyrite oxidation in various depths and areas is highly desirable. Previous laboratory studies have shown the effect of iron bearing minerals on the nuclear magnetic resonance (NMR) response signal. However, further research is required to link these findings to the subsurface pyrite oxidation state or the accompanied sulfate concentrations in the groundwater.

To this end, column experiments containing different pyrite mass-percentages are performed under various redox conditions. The pyrite oxidation in the columns is measured via the mass balance between the inlet, the initial content, and the outlet. In addition, laboratory NMR is used to constantly monitor the column for the entire experiment duration. For modeling purposes, we developed a PHREEQC-based reactive transport model to simulate pyrite oxidation inside the columns. A comparison between the model results, laboratory NMR data, and the experimental measurements provides a basis for the future surface-based NMR applications in the field.

The outcome ultimately enables us to estimate the groundwater contamination due to pyrite oxidation with a NMR-based technique that is less time-consuming, more reliable, and less labor-intensive.

In Germany, all nuclear power plants have been shut down and some are already in various stages of decommissioning. All waste volumes that are not deposited in a repository must pass through officially approved clearance procedures, which are regulated in the German Radiation Protection Ordinance (StrlSchV 2021). After clearance, the materials can be fed into further material cycles or disposed of in accordance with the type of release. The release values of the Radiation Protection Ordinance are based on the 10 µSv criterion. This criterion is intended to ensure the protection of the population from ionizing radiation.

Numerical groundwater models can be used to simulate the distribution of radionuclides and provide information on concentrations in space and time, which can be used as input parameters for calculating possible ingestion doses for different exposure paths.

The basic transport processes of advection, diffusion, dispersion, and sorption are implemented in the simulation codes "Simulation of Processes in Groundwater (SPRING)" (König et al. 2023), “DuMux – Dune for Multiphase flow and transport” (Koch et al. 2021) and "distributed density-driven flow (d3f++)" (Fein & Schneider 1999, Fein 2004). Decay chains can also be modeled in the codes.

The model area represents a simple 2D model and a generic landfill body with its various layer compartments and an associated aquifer. In a further model, the infiltration of precipitation water into contaminated soil with mass transport into the saturated zone is considered. This work presents the first results of the generic numerical groundwater models.

The main objectives of this research are to access ground water,a primary source of drinking water in the urban areas of Hawler Erbil and Bnaslawa in northern Iraq, and the non -carcinogenic human health risks of nitrate contamination associated with drinking water quality. For this purpose, twenty seven ground water samples were collected from wells to asses the hydrogeochemical characteristics and ground water quality for both natural and anthropogenic purposes during the wet (May 2020) and dry (September 2020) seasons.During the wet and dry seasons, NO3 in ground water ranged from 14to 61 mg/L and 12 to 60 mg/L with an average value of 35.7 and 29 mg /L, respectively. Approximately 25.92% of the samples exceeded the permissible limit of the WHO (2011) drinking water standard.the ratio of NO3 /Na vs.Cl/Na and SO4/Na vs. NO3 /Na indicate the effect of agricultural activities and waste water leakage from cesspools or septic tanks on the quality of ground water during the wet and dry seasons. The entropy weighted water quality index method ranked 62.5% and 75% of the urban ground water as not recommended for drinking, the remaing samples are moderately suitable in both wet and dry seasons.Due to high nitrate in drinking water, non-carcinogenic human health risk levels vary as infants >child> adults.The main findings obtained from this study can assist policymakers in better understanding the hydrogeochemical properties of ground water in terms of drinking water safety, thereby facilitating the management of water resources to take the necessary measures.

Understanding the biogeochemical processes that lead to the enrichment of dissolved phosphorus in groundwater is crucial, especially as concentrations exceeding 1 mg L^-1 occur in many floodplain and delta aquifers. These elevated concentrations of primarily inorganic orthophosphate can cause eutrophication in surface waters and mobilize toxic elements like arsenic.

Here, we provide a comprehensive overview of the biogeochemistry of phosphorus within groundwater systems, aiming to elucidate how phosphorus interactions with other elements influence its behaviour. Our methods include chemical analyses of groundwater and aquifer materials, laboratory and field experiments, isotope analysis, and geochemical modeling.

Our findings indicate three primary processes responsible for the release of phosphorus into groundwater: apatite weathering; microbial mineralization of organic matter, which generates dissolved phosphorus as a by-product; and the reductive dissolution of iron-(hydr)oxides that serve as hosts for phosphorus. Additionally, phosphorus undergoes microbial processing during its transport, as evidenced by phosphate-bound stable oxygen isotope analysis. Phosphorus may also be immobilized by (co-)precipitation of secondary minerals (e.g., calcium-phosphates or iron minerals) or through surface adsorption. Notably, phosphorus immobilization often takes precedence over arsenic immobilization, enhancing the mobility of the latter.

The occurrence of these mobilization and/or immobilization processes largely depends on local groundwater characteristics and the aquifer's mineralogical composition. Our results highlight the intricate links between the fate of phosphorus and the biogeochemical cycles of calcium, carbon, iron, arsenic, and possibly sulphur, suggesting potential strategies for in-situ groundwater remediation approaches.

Sinich/Sinigo, situated within the Athesian Volcanic District in Northern Italy, yielded an exceptional plant fossil assemblage from the middle Kungurian (Cisuralian), including permineralized stems, compressions, and molds of such diverse plant groups as lycopsids, sphenophytes, ferns, seed ferns, cordaitaleans, and conifers. Notably, the site features the earliest record of coexistence of walchian and voltzian Voltziales conifers, whose exceptional three-dimensional preservation provides evidence of xeromorphic adaptations such as fleshy and deciduous leaves. Additionally, the basin contains the oldest in situ fossil forest in Italy, which was preserved in its original growth position on a deltaic sheetflood fan and subsequently buried by mass flows, illustrating the conifers' significant ecomorphological adaptability in response to waterlogged conditions. Palynological analyses reveal a predominance of woody tissue and charcoal in the lower and middle part of the succession with an increase of spores and pollen in the upper part of the succession. Geochemical analyses on trace elements are rather monotonous in the lower part of the successions but show notable fluctuations in the upper part with pronounced peaks in the abundance of S, As, Pb. Indices of chemical alteration (CIA, PIA, CIW) support significant environmental changes in the later stages of the evolution of the basin, while the isotopic composition of bulk organic carbon remained stable. These analyses underscore Sinich/Sinigo as a key site for understanding the ecological and environmental dynamics of the middle Kungurian, offering valuable insights into the interactions between volcanic activity, weathering and biotic responses.

Since its appearance on land in the early Paleozoic, life has conquered the continents with astonishing diversity. From the deepest caves to the atmosphere, numerous evolutionary innovations such as active flight or seeds paved the way for life beyond water. However, we still have a rough idea of the timelines of terrestrialization, mainly because fossil evidence remains patchy. It is therefore crucial to know the age and taphonomy of the few finds well. One such example is Tridentinosaurus antiquus, Italy’s oldest fossil reptile from the lower Permian Athesian Volcanic Group, Southern Alps. This specimen potentially enlightens the earliest ecosystems that coped with extensive volcanism, but its stratigraphic context is barely referenced. We clarify the provenience, age, fossilization and paleoecological meaning of T. antiquus using sampling-history review, field mapping, mineral chemistry and U-Pb radioisotopic dating. Accordingly, rock petrography and biotite composition prove that a crystal-rich, monotonous intermediate tuff from the Regnana Formation at Stramaiolo, Northern Italy, is the host rock of T. antiquus. Biotite crystallization in both field samples and the rock attached to the fossil yield values of 670±17°C and 1.7–2.0 kbar close to the granite solidus, strengthening a common magmatic history. The tuff formed from hot, diluted pyroclastic density currents that filled a paleo-valley between small volcanoes around 275 Ma. T. antiquus, hence, is par-autochthonous and truly inhabited the volcanic landscapes. Along with fossil plants and other similar taphocoenoses worldwide, this fossil documents the presence of differentiated ecosystems in late Paleozoic volcanic environments.

The reconstruction of paleocurrents is crucial for understanding ancient environments and the past climate. Such reconstructions are often based on the distribution of marine species as well as on geochemical proxies. In this talk, a new approach is proposed which uses the occurrence of glendonites as a proxy for cool bottom currents. Glendonites are pseudomorphs after the hydrous carbonate mineral ikaite that only forms in environments characterised by near-freezing temperatures. The pseudomorph has been identified in a number of Phanerozoic successions deposited in high latitudes. However, occurrences in mid-latitudinal sections have also been reported. These occurrences are of particular interest as they document the formation of glendonite in temperate areas, where the prevailing temperatures were above the threshold required for the precipitation of the precursor mineral ikaite.

This study investigates a recently discovered glendonite-bearing interval from the Buttenheim clay pit section (Bavaria, Germany), which represents the southernmost glendonite occurrence in the late Pliensbachian (Early Jurassic). Based on geochemical and sedimentological analyses, the glendonite-bearing interval is interpreted as the result of cold bottom-water masses which originated in the Arctic Sea and migrated southward into the Tethys Ocean, thereby passing the extensive shelf areas of the European epicontinental sea. The influx of cold water caused a significant temperature decrease in the deeper parts of the epeiric sea, which led to the formation of glendonites in lower latitudes. This model can help to explain unexpected mid-latitudinal glendonite occurrences and can serve as a valuable tool for the reconstruction of paleocurrent patterns.

The Late Cretaceous epoch was characterized by extreme greenhouse climates and widespread glaucony formation in marine shallow water settings. In the Danubian Cretaceous Basin (DCB, Bavaria, SE-Germany), contemporaneous and closely-spaced shallow-marine accumulation of glauconitic strata in the eastern and the glaucony-free Neuburger Siliceous Earth in the western parts of the basin during Cenomanian–early Turonian times represents an unsolved phenomenon with great potential to unravel important aspects of the poorly understood mechanisms of Late Cretaceous glaucony formation.

An integrated sedimentologic, stratigraphic, mineralogic and geochemical approach reveals that the striking small-scale lithofacies differences can be attributed to the geological structure of the hinterland and the nature of elemental influx: in the eastern DCB, deeply chemically weathered granites and gneisses of the Bohemian Massif were leached due to the warm climate and high precipitation rates, and elements crucial for glaucony formation (K, Fe, Si, Al) were amply supplied by rivers, fueling a shallow marine greensand giant (Regensburg Formation). In the western DCB, a hinterland consisting of karstified Jurassic carbonates devoid of elements necessary for glaucony formation and a lack of significant fluvial input repressed the shallow marine glaucony factory. Furthermore, the originally rather marly sediment of the Neuburg Siliceous Earth of the Wellheim Formation was affected by early diagenetic silicification due to a combination of inflowing silica-rich groundwater from karst aquifers and dissolution of biogenic siliceous components. Additionally, our geochemical data provide the first evidence of a redox-sensitive trace metal drawdown during Oceanic Anoxic Event 2 in shallow water/coastal settings in Germany.

Massive and (geologically) fast shallow-marine glaucony formation was a widespread phenomenon during the Cretaceous greenhouse world that has no recent analogue. Based on several integrated case studies from different basins around the Mid-European Island, we intend to better understand the geochemical and depositional constraints on Late Cretaceous glaucony formation. X-ray diffraction analyses showed that the abundant green grains and matrix of all sites definitely constitute glauconitic minerals with high-order, 1M-type layer stacking. Inorganic geochemical analyses, normalized to Al and compared to average shale (AS), demonstrate that most element/Al ratios of greensand deposits are higher than AS values, including the chemical index of alteration (CIX). These observations suggest an intense chemical weathering of the exposed hinterlands, resulting in a continuous supply of essential elements required for glaucony authigenesis in nearshore settings under variably reducing and/or oxidizing redox conditions, associated with somewhat increased palaeo-productivities. The leaching of palaeosols and swampy coastal low-/wetlands during major transgressions related to eustatic Late Cretaceous sea-level rises was an important process for trace metal and nutrient mobilization. Furthermore, the significant influx of terrestrial organic matter from the densely vegetated continents suggests a significant impact of plant-decay-related potassium to glaucony maturation. In a nutshell, our new integrated data provide novel insights into the anactualistic formative processes of authigenic glauconitic minerals during greenhouse phases of Earth history.

The continental response to global climate forcing remains difficult to predict due to the intricate feedbacks among climate, vegetation and other land surface changes. This is exemplified by the Eocene-Oligocene Transition (EOT; 34 Ma), where a 2-3°C cooling event is observed in marine records around the world, but continental records from the North American Great Plains suggest more extreme cooling of 7-8°C instead. Here we present a new Oligocene record from the adjacent high-elevation North American Cordillera (Cook Ranch section; SW Montana) constrained by four radiometrically dated tuffs. Dual clumped isotopes (Δ₄₇ and Δ₄₈) of this record suggest no major changes in temperature across the EOT, but instead show extreme cooling of 10±1°C in the early Oligocene (32-30 Ma). Based on paleobotanical and climate model data, we interpret this as summer cooling coeval with a decrease in atmospheric CO₂ identified in recent proxy compilations. This long-term Oligocene cooling may explain the lack in mammal response observed in North American fossils compared with other continents.

By our DFG funded project “On sedimentation pattern of the eastern Canary Islands”, we are concentrating on two sediment archives, the dune sequences on Fuerteventura and the Vega sequences on Lanzarote. So called “Vegas” are dammed valleys which act as sediment trap since the damming. The vega sediments consist of redeposited (soil-)sediments from the slopes, volcanic material and dust deposits originating from the northern African continent. In those vegas well differentiated sediment layers can be recognised with alternating pale calcified layers (pcl) and reddish clay dominated layers (rcl). This alternation shows a recurring pattern within the profile. So far we interprete such a sequence of one pcl and one rcl as follows:

A massive deposition of silt dominated dust is followed by a period of de- and recalcification. At the same time, soil formation takes place on slope positions within the catchment due to more humid conditions. With the onset of aridisation, clay dominated material (> 80% clay) from the slopes is transported to the valley floor with a simultaneous increase in dust accumulation. The aridisation culminates in a next massive aggradation of silt dominated dust.

The transition from a pcl to a rcl above is characterised by a quartz and Zr minimum. Within the rcl layer the quartz and Zr contents increase continuously (due to increasing dust input) and reach its peak during the next massive dust event. Whereby massive dust events seem to be linked to terminations of African Humid Periods.

Microfossils as part of multi proxy analyses are a powerful tool to reconstruct environmental changes, sea level fluctuations and coastal development. In combination with datasets, deriving from sedimentological and geochemistry analyses it is possible to follow coastal evolution from open marine to coastal limnic environments. The method is also used in geoarchaeological studies, especially to present an active phase of an ancient harbour, but the infilling of a harbour basin can also use as geo-bio archives. Concerning the microfossil inventory, harbours are very similar to lagoons in habitat type and ecology due to their protected position. In harbour basins, eutrophication is common, caused by the input of human waste and the reduced exchange of water. This is reflected by a ubiquitous faunal association, adapted to temporary deficiency in oxygen. Often, the sedimentation rate is higher than in natural lagoons. Silting up of a harbour leads to the separation from the sea followed by a freshening of the water body with a characteristic freshwater fauna and an increase of organic matter during the final phase. This marked change in the faunal composition, including ostracod freshwater species and the rapid reduction of foraminifer species indicates the disconnection to the sea and the end of the harbour activity. In this study we present the Roman Harbour of Ephesos and the Hellenistic Harbour of Elaia regarding microfossil distribution, sedimentation processes, landscape evolution and human impact. The key difference between the two harbour sites are the various sedimentation rates and the human impact.

Due to their widespread use in high-tech products and processes, the rare earths and yttrium (REY) are nowadays considered as emerging microcontaminants in the environment. Accordingly, a good understanding of their biogeochemistry is highly relevant. Yet, the knowledge gap regarding the incorporation and fractionation of REY in biological and biogenic samples is still surprisingly large.

In contrast to marine and freshwater mollusc shells, only little has been published on REY in terrestrial mollusc shells. This is rather surprising as “Roman snails”, for example, are used for human consumption and considered a delicacy of the “French Cuisine”. The habitat of this land snail (Helix pomatia) extends over many countries in Europe. Its aragonitic shell precipitates from the snail’s mantle epithelium, implying that all REY incorporated into the shell must have been bioavailable to the organism.

We will present complete REY data for Helix pomatia shells from locations with different lithologies from several European countries. The shale-normalised REY (REY_SN) patterns of all shells show a light and/or middle REY enrichment relative to heavy REY. Furthermore, most samples show small positive La_SN, pronounced negative Ce_SN and slightly positive Y_SN anomalies. We will discuss these features and compare the REY_SN patterns with data of ambient substrate (rock or soil), plant samples and Cepaea snails, which are among the most widespread snails in Europe.

As a result of their widespread use in various high-tech applications, Rare Earths and Yttrium (REY) have become microcontaminants in freshwater systems. However, their biogeochemical behavior, particularly their uptake by aquatic organisms, remains poorly understood. In this study, we investigated the distribution of REY in different soft tissues and shells of freshwater bivalve A. anatina, along with REY levels in ambient water from the Danube River in Hungary and the Vistula River in Poland, as well as in their potential food sources. Regardless of the origin of the samples, all compartments of the mussels exhibit very similar shale-normalized REY patterns. Despite Gd contamination of the river waters from MRI contrast agents, no anthropogenic positive Gd anomalies were observed in any mussel sub-samples. This suggests that anthropogenic Gd from MRI contrast agents may not be bioavailable in freshwater, or that REY from ambient river water do not significantly contribute to the REY uptake of freshwater mussels.

Compared to ambient water, bivalves accumulate REY, particularly Ce and light REY. However, REY concentrations in mussels are generally lower than those in their potential food sources, with minor fractionation along the REY series, except for preferential uptake of La and Y. Comparison of shells and tissues does not indicate any major fractionation during transfer within the mussels or shell formation. Mussel shells, therefore, may serve as convenient indicators for environmental monitoring of REY, without significant interference from vital effects.

The Great Barrier Reef (GBR)is a unique environment almost 300 times bigger than the next biggest barrier reef system. One of the key questions about this system is what conditions allowed the formation of this environment. Given the influence of Sea Surface Temperature (SST) on modern reef environments, it was originally assumed that it was related to changes in SST. However, there is a lack of SST records for the late Pleistocene for the area around the Great GBR. We used TEX₈₆^H to produce a new SST record starting at 900 ka from ODP Site 820 next to the northern GBR. Before MIS 17, summer SSTs were as low as 26-24 degrees during glacials. While reefs can persist at these temperatures, reef expansion is limited by the cold conditions. Then, there is an increase in temperature around MIS 17. This is followed by a period of relatively of stable SST between MIS 17-13, with glacial summer SSTs above 27 degrees. This period matches the establishment of the GBR at MIS 17 (700 ka) and then the development of the permanent reef system around MIS 13 (500 ka). This period of relatively stable SSTs might have allowed the system to develop and expand within a narrow window ideal for coral Reef growth, even during glacials. Therefore, our research suggests that major steps in the development of the Great Barrier Reef system are linked to changes in the SSTs.

Oxygen isotopes (δ¹⁸O) from biogenic apatite are used for the calculation of seawater temperatures in paleoclimatic reconstructions. While conventional δ¹⁸O analyses by IRMS (isotope ratio mass spectrometry) requires sample quantities of more than 1 mg, in situ SIMS (secondary ion mass spectrometry) minimizes sample size and thus the risk of contamination of the primary δ¹⁸O signal. Despite this obvious advantage, there are some critical points that could influence the final δ¹⁸O values and their interpretation: (1) The conventional IRMS method exclusively measures the δ¹⁸O from the isolated PO₄³⁻ group of biogenic apatite (Ca₅(PO₄, CO₃, F)₃(OH, F, Cl, CO₃)). In contrast, SIMS releases the oxygen from all molecular groups and from organics. But, to what extent do these non-PO₄³⁻ bound oxygen isotopes bias the final δ¹⁸O values? (2) Thermometer equations are based on IRMS analyses. Are these equations also applicable to SIMS data? (3) Thermometer equations assume, that the δ¹⁸O of seawater signature is –1‰ or 0‰ (VSMOW) for ice-free or ice-covered oceans, respectively. These data are based on sub-recent glacial-interglacial cycles and the associated δ¹⁸O seawater signatures. Whether the oxygen isotopic composition of seawater has changed during the earth history is still under debate.

Clarification of these aspects is crucial for a reliable assessment of δ¹⁸O values and the calculation of seawater temperatures. For this reason, we compare δ¹⁸O data of recent shark teeth analyzed by IRMS and SIMS. Our sharks lived during documented seawater temperatures, ph-values, and δ¹⁸O signatures and are therefore the ideal subjects for our study.

Seit über 300 Jahren wird Kaolin in Sachsen abgebaut. Ehemals allein zur Herstellung von Porzellan wird heute Kaolin auch in der Papierindustrie, Farben- und Lackindustrie und vielen weiteren Anwendungen verwendet. Primärkaolin in Sachsen entstand maßgeblich während des Paläogen und Neogen durch tropische Verwitterung aus feldspatreichen felsischen bis intermediären magmatischen Gesteinen oder klastischen Sedimentgesteinen. Diese Verwitterungskrusten waren einst weiträumig in Mitteleuropa verbreitet, wurden jedoch meist erodiert. Die Primärkaoline sind nur dort erhalten, wo sie durch tektonische Bewegung versenkt und überdeckt wurden.

Wie alle staatlichen geologischen Dienste ist auch der sächsischen dazu verpflichteten Karten der oberflächennahen Rohstoffe (KOR50) zu erstellen und regelmäßig zu aktualisieren. In früheren Umsetzungen dieser Karten wurde ein theoriedominerter Ansatz zur Erstellung der KOR50 für Kaolin gewählt. Dabei wurde von einer flächendeckenden, ungestörten Verbreitung von Kaolin liegend zu Schichten des Paläogen ausgegangen. Notwendige Vorbedingungen wie das Vorhandensein geeignete Ausgangsgesteine oder die Abtragung der Kaolinkrusten wurde dabei vernachlässig.

Für die aktuelle Überarbeitung der KOR50 für Kaolin wurde ein stärker evidenzbasierter Ansatz zur Erstellung der Rohstoffpotenzialflächen gewählt. Als Arbeitsgrundlage zur Überarbeitung diente vor allem die sächsische Bohrdatenbank. Außerdem wurden Abstandsregeln von Bohrungen festgelegt, sowie weitere Bedingungen welche den Erkundungsgrad einer Rohstoffpotentialfläche bestimmen. Mit Hilfe von SQL-Abfragen konnte die Anzahl der zu sichtenden Bohrungen stark reduziert werden. Anhand dieser ausgewählten Bohrungen konnten zahlreiche neue Kaolinvorkommen identifiziert werden. Insgesamt wurde 854 Kaolinpotentialflächen an den aktuellen Kenntnisstand angepasst, neuentdeckt oder ehemalige Flächen verworfen. Außerdem wurden durch Interviews mit Kaolinabbaubetreibenden Firmen Kriterien bestimmt, die in einen weiterentwickelten Bewertungsschlüssel für Kaolinvorkommen einflossen.

Calcined clays are promising sustainable alternative materials for cement production. By calcining natural clay minerals (usually 600–900 °C), they become reactive and can be used as a partial replacement for Portland clinker in cement production. This results in a lower carbon footprint and reduced energy consumption in the production process.

Replacing cement clinker with so-called supplementary cementitious materials (SCM) such as fly ash and blast furnace slag has been done for several decades. Calcined clays have also been used, mostly in the form of metakaolin, which significantly improves the strength and durability of mortar and concrete. However, its limited availability and high cost restrict its practical application to a few specialist applications.

In comparison, 2:1 clay minerals such as illite or smectites are more widely available and economically attractive due to their lower costs. Recent research has explored the use of calcined 2:1 clay minerals as SCM, but their properties and efficient production are still not fully understood.

In the present work, different clays from Germany are characterized and tested as potential calcined clay. Besides conventional calcination using a rotary kiln, fluidized bed calcination is used to improve the reactivity of the calcined clays while being less time-consuming and therefore more energy efficient.

Rohstoffvorkommen und deren Gewinnung spielen in Sachsen seit Jahrhunderten eine große Rolle. Erzen und Spaten kommt dabei eine besondere Bedeutung zu, begründete doch vor allem der Bergbau auf Silber den Reichtum Sachsens. Die Aufgabe, das Wissen über Bodenschätze und Bergbau zu sammeln und zu erhalten, wird im Freistaat von verschiedenen Institutionen wahrgenommen, z.B. vom Geologischen Dienst Sachsens als Teil des Landesamtes für Umwelt, Landwirtschaft und Geologie (LfULG), vom Sächsischen Oberbergamt (OBA) und vom Sächsischen Bergarchiv.

Bereits 2012 beschloss die Sächsische Staatsregierung die 1. Sächsische Rohstoffstrategie mit dem Ziel, die Rahmenbedingun­gen für den heimischen Bergbau hinsichtlich wirtschaftlicher und nachhaltiger Aspekte zukünftig aktiv zu gestalten. Ein entscheidender Faktor um sich diesem Ziel zu nähern, ist die Verfügbarkeit von Daten zur Geologie, den Lagerstätten und den Rohstoffen. Diese Daten sind jedoch geschichtlich begründet großräumig über verschiedenste Institutionen, Ämter, Behörden und ehemalige Bergbaubetriebe mehrerer Bundesländer verteilt. Um sächsische Rohstoffdaten für Wirtschaft, Wissenschaft und Fachverwaltung in Wert zu setzen, startete 2013, aufbauend auf einer Initiative und umfangreichen Vorarbeiten des Geokompetenzzentrums Freiberg e.V., das Projekt ROHSA 3 (Rohstoffdaten Sachsen). Mit Ressourcen des Freistaates Sachsen wurden durch ein Projektteam des LfULG und des OBA aus über 20 Archiven bisher über 10.000 Metadaten von Dokumenten recherchiert und erschlossen, 45.000 Dokumente gesichert und gescannt sowie 700 Wismut-Bohrungen, 220.000 geophysikalische und 250.000 geochemische Punktdaten digitalisiert. Um diesen wertvollen Datenschatz nutzen zu können, wurde eine neue Onlineplattform erstellt, mit deren Hilfe direkt auf die Daten zugegriffen werden kann (www.rohsa.sachsen.de/suche).

Die Sächsische Staatsregierung verfolgt mit ihrer Rohstoffstrategie unter anderem das Ziel, die Entwicklung des gesellschaftlichen Rohstoffbewusstseins zu unterstützen. Das Rohstoffbewusstsein ist im Unterschied zum Umweltbewusstsein in der Bevölkerung weit weniger präsent, obwohl auch die Rohstoffwirtschaft eine wesentliche Lebensgrundlage der menschlichen Gesellschaft darstellt.

Das Sächsische Oberbergamt unterstützte dieses Anliegen mit der Erstellung des Sächsischen Naturwerksteinkatasters. Für die wichtigsten Natursteinlagerstätten im Freistaat Sachsen soll das Kataster die potentiellen Natursteinnutzer (staatliche und private Bauherren, Architekten, Planer, …) auf den Gebieten der Denkmalpflege, des Gesellschafts- und Industriebaus sowie im privaten Bausektor zur Auswahl einheimischer Materialien anregen.

Gleichzeitig ist das Kataster auch dafür gedacht, den Bekanntheitsgrad sächsischer Natursteine in der breiten Öffentlichkeit zu erhöhen. Dafür wurden neben wesentlichen bauenden Lagerstätten auch einige historische, nicht mehr bebaute Lagerstätten in das Kataster einbezogen, da sie für eine Reihe sehr bekannter Naturwerksteine stehen, wie zum Beispiel der Chemnitzer Zeisigwaldtuff, der Zöblitzer Serpentinit oder der Wildenfelser Marmor.

Das Kataster beinhaltet einen umfangreichen bauhistorischen Abriss zur Werksteinnutzung in Sachsen, einen Überblick über die Geologie der Naturwerksteine in Sachsen, eine Abhandlung über die Bestimmung und den Aussagewert ihrer petrophysikalischen und gesteinstechnischen Kennwerte sowie eine Übersicht über weitere historisch bedeutsame sächsische Baugesteine.

Der spezielle Teil des Katasters beinhaltet für 34 Gesteine/Steinbrüche Datenblätter, in denen Daten zu den Steinbrüchen und den gesteinstechnischen Kennwerten der Gesteine, aber auch makroskopische und mikroskopische Gesteinsbeschreibungen, der Mineralbestand, zur Verwendung der Gesteine, den Referenzobjekten und zum heutigen Zustand der Steinbrüche zusammengestellt sind. Das Kataster ist mit einer Vielzahl hochwertiger Fotos illustriert.