Sources Of Organic Matter And Environment Of The Hongshuizhuang Formation Of The Yanliao Gully In The Middle Proterozoic Of Hebei Province

The discovery of several buried hill reservoirs and sets of high-quality source rocks in the Mesoproterozoic in North China Craton has proved that China's Mesoproterozoic has good oil and gas exploration potential.The preservation environment of deposition has important significance for the formation of source of organic matter,and the main source of sedimentary organic matter in the Middle Proterozoic is still unclear.In order to clarify the occurrence environment of ancient source rocks and the source of parent material,this paper selects the samples of each layer of the Middle Proterozoic Hongshuizhuang Formation in North China,and conducts research through various geochemical methods:(1)The marine environment nutrient status of the Hongshuizhuang Formation was generally good,and its content change was mainly controlled by the redox environment.Most important part of the Hongshuizhuang Formation was developed in the marine environment that reduction and oxidation-reduction are alternated,and the buried organic carbon in the sediment is formed in a medium to high paleoproductivity background.(2)The main types of source of organic matter in the Hongshuizhuang Formation are protokaryon plankton and bacteria.At the same time,sterane that originates from eukaryotic algae was also detected in bitumen "A" extraction.However,although there are eukaryotic algae contributes in the organic source of Hongshuizhuang Formation,the portion of contribution is very low,and the source of organic matter is mainly contributed by lower prokaryotes.In summary,this paper proposes that the sedimentary environment of black shale's organic matter in the Middle Proterozoic Hongshuizhuang Formation in China is an anoxic environment with high organic carbon content.The source of organic matter is mainly prokaryote,contribution from eukaryotic algae exists but its contribution is not high.This is of great significance for the evaluation of source rocks in oil and gas exploration in the Middle Proterozoic.