Main factors controlling the organic matter enrichment in the Lower Cambrian sediments of the Sichuan Basin, SW China

The Lower Cambrian Qiongzhusi Formation contains more than 200 m of marine sediments mainly consisting of mudstone and black shales, which are widely accepted as the most important hydrocarbon source rocks of the Ediacaran–Cambrian giant gas field in the Sichuan Basin. The geochemical compositions of biomarkers and trace elements obtained from black shales at the bottom of the Qiongzhusi Formation were used to reconstruct the palaeoproductivity...