Organic geochemistry of Cretaceous black shales from Deep Sea Drilling Project Site 530, Leg 75, eastern South Atlantic.

Abstract

Cretaceous sediments were drilled north of the Walvis escarpment in Hole 530A. An immature stage of evolution for organic matter can be assigned to all the samples studied. Cyclic variations of organic matter observed for a sequence can occur for a set of sequences and even for some consecutive sets of sequences. Climatic factors are proposed to account for the cyclic sedimentation and distribution of organic matter for every sequence that includes a black bed.-from Authors