Variscides everywhere? Multi-stage sedimentary recycling in Central Europe

We used original detrital zircon morphology, trace element, and U-Pb age data obtained from Upper Rotliegend II strata (Upper Permian) to reveal sedimentary fluxes within the Central German Basin. Understanding the evolution of such a system is crucial for further studies, given that the North German Basin is storage to vast natural gas resources and may also serve as an intermediary sedimentary repository for younger strata.

The detrital zircon dating results revealed the presence of main age clusters from the Permian, Carboniferous, and Cambrian periods. Additionally, several minor clusters from the Neo-, Meso-, and Palaeoproterozoic eras were also identified. These ages are remnants of the Cadomian and Variscan orogenies and the opening and closure of the Rheic Ocean. Zircon grain morphologies varied from completely unrounded to completely rounded grains across the age range. The heterogeneity of the data obtained from the studied mineral grains is vital to understanding the sedimentary history of the Central German Basin. It suggests that the basin fill is most likely a mixture of repeatedly recycled material and directly derived material from bedrock sources.

The detrital zircon trace element data support these findings, showing a wide range of values indicating different magma sources. These results underline the complexity of detrital zircon, and shed further light on the sedimentary history of the Central German Basin. We also found that the North German Basin is an integral part of a sedimentary recycling system spanning Central Europe, which is active since the Neoproterozoic.