The North German Basin – A story told by zircon of drill core G1/86

Zircon from North German drill cores represent an important archive for reconstructing sedimentary processes. In this study, we analyzed magmatic zircons from rhyolites (Lower Permian) and detrital zircon grains from the Upper Rotliegend II strata (Upper Permian) in the southern North German Basin, using a multi-proxy approach that includes morphology, trace element composition, U–Pb geochronology, and Lu–Hf isotopic data. The dataset allow us to trace sedimentary fluxes and provenance pathways within the basin. Understanding the evolution of such an extensive sedimentary system is essential, considering the basin’s significance in reconstructing sediment dynamics within a supercontinent configuration.

We dated a rhyolite marking the base of the succession to 296±2 Ma. This volcanic unit is overlain by fine-grained sandstones. Detrital zircon grains from these sandstones exhibit a progressive change in roundness—from predominantly angular to mostly rounded—across all age groups, indicating varying degrees of sedimentary reworking. U–Pb dating of zircons from the lower core sections reveals major age populations corresponding to the Permian, Carboniferous, and Cambrian periods, alongside minor contributions from the Neo-, Meso-, and Paleoproterozoic eras. These age spectra reflect the tectonothermal imprints of the Cadomian and Variscan orogenies and sediment recycling linked to the evolution of the Rheic Ocean. In contrast, the upper core shows an influx of Meso- to Paleoproterozoic material, likely sourced from Baltica. This compositional and morphological diversity highlights the complexity of sedimentary processes in the Central German Basin and points to a dynamic interplay between recycled detritus and input from exposed crystalline bedrock.