Paleo-oceanographic Conditions of the Middle Cretaceous Marine Organic Carbon Accumulation in

摘要

INTRODUCTION Middle Cretaceous is one of the most important periods in global organic matter (OM) accumulations in the earth's history. The organic carbon-rich sediments are widely developed in the Middle East and Siberia, and are important hydrocarbon sources for many large oil fields (Klemme and Ulmishek, 1991). This period is also featured by a series of significant global geological events (Larson, 1991). The role of the environmental events and the biological pump in the organic matter accumulation remains largely unclear. In particular, the preservation (Schlanger and Jenkyns, 1976) and the productivity models for the organic accumulation are not well understood. It is thus necessary to investigate the paleo-oceanographic conditions to decipher the accumulation of the Middle Cretaceous marine organic carbon.