Cutting samples of 23 geological formations from different depths (measured depth, MD) between 1.4 and 4.4 km of the geothermal research well Groß Schönebeck site were analyzed with focus on lithium (Li), copper (Cu), and strontium (Sr).
To determine how strong and to which components these critical raw materials (CRM) are bound within the rocks, leaching and sequential extraction experiments were performed on five selected formation rock samples that are considered either for geothermal exploitation (Muschelkalk, Buntsandstein, Rotliegend sandstone) and/or as potential source for the CRM Li, Cu, Sr from the Permo-Carboniferous volcanic rocks and/or the Ohre anhydrite. In addition, electron probe micro analyses (EPMA) and laser ablation ICP-OES was performed on thin sections of the Rotliegend formation.
Real-time fluid monitoring began in late 2020 in the East Eifel and currently includes 12 sites, such as abandoned CO₂ wells, mofettes, CO₂-rich springs, CO₂-rich soil, and a cold-water geyser in the West Eifel. For the first time, fluid data are being recorded continuously with a high temporal resolution of up to 1 Hz. Depending on the local site conditions, the following parameters are being monitored: instrument temperature and battery voltage; barometric pressure and temperature; meteorological parameters; water level, wellhead pressure, water temperature; radon in free gas phase; CO2 concentration and CO2 flux in soil gas. Data are transmitted hourly via FTP to GFZ. While we generally observe small seasonal variations, short-term transients related to heavy rain or local and distant earthquakes are indicated. Over longer periods, we observe trend changes in helium isotope ratios, radon concentration, and water temperature. For example, two sites exhibited significant helium isotope changes from 2021 to 2025, which appear to correlate with earthquake swarms at depth. These examples demonstrate the necessity of jointly interpreting meteorological, hydrogeological, geophysical, and geodetic data.
The Herat-Panjshir-Badakhshan—the Paleo-Tethys—suture zone of Afghanistan marks the vestige of the subducted Paleozoic-early Mesozoic Paleo-Tethys oceanic lithosphere. We investigate the evolution of rocks north of this suture in the Hindu Kush and Pamir of Afghanistan. Our study identifies Carboniferous and Middle-Late Triassic continental arc magmatism, Paleo-Tethys oceanic relicts, and a mostly Middle Triassic accretionary wedge that underwent Late Triassic amphibolite-facies metamorphism and migmatization.
The Supporting Information to the publication provides: data tables of the analytical results (Tables S1, S3, and S4); a summary of the U-Th-Pb petrochronology (Table S2); a stratigraphic column of the hanging wall (north side in present coordinates) of the Paleo-Tethys suture zone (Turan-Karakum block) (Figure S1); a graphical representation of the U-Th-Pb petrochronology and specific zircon, titanite, and allanite trace element relationships (Figure S2); 40Ar/39Ar spectra and inverse isochron plots (Figure S3); rock classification diagrams with a petrographic thin-section documentation (Figure S4); and supplementary geochemistry plots (Figures S5 and S6).