The depositional environment of Jurassic organic-rich sedimentary rocks in NW Europe : a biomarker approach

Abstract

Information on the depositional environment of sediments and sedimentary rocks can be obtained in several ways, using e.g. sedimentological, palynological or (micro)palaeontological approaches. In this thesis, results are presented of molecular organic geochemical investigations, aimed at palaeoenvironmental reconstruction, of organic-rich sedimentary rocks of Jurassic age. Sample locations are in France, England and Germany. Particular attention has been paid to organic sulfur compounds, which have proven valuable biomarkers in earlier studies of Cretaceous and younger samples. The structural elucidation of the molecular fossils was performed by gas chromatography-mass spectrometry and thermal and chemical degradation techniques. Compound-specific stable carbon isotope analysis was applied to obtain additional information on the origin of molecular fossils (e.g. habitat ofthe source organism, way of carbon uptake of the source organism).