Biomarkers, stable carbon isotope, and trace element distribution of source rocks in the Orange Basin, South Africa: implications for paleoenvironmental reconstruction, provenance, and tectonic setting

Abstract Aptian to Campanian sediments from the Western offshore Central Orange Basin were studied by integrating molecular geochemistry, inorganic and isotopic studies recognize their geochemical characteristics via reconstruction of basin’s paleoweathering, paleosalinity, paleovegetation, paleoclimate, tectonic records. Molecular analyses both aliphatic aromatic compounds reveal an input dominantly a marine source. The source rocks accumulated in reduced, anoxic, saline water column. Based on various biomarker proxies vitrinite reflectance data, some samples are thermally mature produce petroleum, while others not. According V/Ni ratio, South Africa mainly with only few ranging suboxic anoxic. This is congruent isotope that further indicate presence marine-derived terrestrial remains generating hydrocarbons. investigated made up intermediate igneous have undergone moderate chemical weathering. Geochemical figures setting discriminant function diagrams revealed continental rift passive margin settings. As result, extrapolated crustal processes directly analogous genesis evolution Basin, demonstrating Gondwana’s breaking opening Atlantic Ocean Margin.