Reconstructing the evolution of the latest Pennsylvanian-earliest Permian Lake Odernheim based on stable isotope geochemistry and palynofacies: A case study from the Saar-Nahe Basin, Gennany

摘要

Finely laminated sediments archived the evolution of the latest Pennsylvanian-earliest Permian Lake Odernheim, Saar-Nahe Basin, Germany. A succession of evolutionary stages can be distinguished based on variable carbonate carbon (-5 to +2 parts per thousand) and oxygen (-7 to +5 parts per thousand) isotopic compositions of dolomite. Sedimentary organic matter represents primarily a mixture of detrital vascular plant material (delta C-13 around -21 parts per thousand) and lake derived photosynthetic algal matter (delta C-13 around -27 parts per thousand). This distinction based on organic carbon isotopes is further supported by palynofacies analyses and Rock-Eval data. An additional contribution from bacterial biomass is likely. Bacterial sulphate reduction, and thus anaerobic remineralization of sedimentary organic matter, is indicated by the presence of sedimentary pyrite.