Palaeoproductivity and organic matter accumulation during the deposition of the Chang 7 organic‐rich shale of the Upper Triassic Yanchang Formation, Ordos Basin, China

The lacustrine Chang 7 organic‐rich shale of the Upper Triassic Yanchang Formation is a very important hydrocarbon source rock and contains high total organic carbon content (average = 5.54 wt.%). Previous studies suggest that deposits of the Chang 7 accumulated slowly under dominantly oxic–suboxic bottom‐water conditions occasionally interrupted by the establishment of anoxic conditions. However, questions remain regarding the role of...