Reconstruction of sedimentary paleoenvironment of Permian Lucaogou Formation and its implications for the organic matter enrichment in south-eastern Junggar Basin,China  

作　　者：Yong TANG Xiatian WANG Tao WANG Chenlu HEI Shuang LIANG Hu CHENG 

机构地区：[1]Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay 834000,China [2]School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China

出　　处：《Frontiers of Earth Science》2024年第3期526-537,共12页地球科学前沿（英文版）

基　　金：supported by the PetroChina Xinjiang Oilfield Branch(Exploration and Development Research Institute)Project“Formation Environment,Abundance Conditions and Scientific Exploration Well Site Selection 2021 of Permian Hydrocarbon Source Rock in Junggar Basin”(No.33412022047).

摘　　要：The Permian Lucaogou Formation represents one of the most important hydrocarbon source rock intervals in the Junggar Basin,although the sedimentary paleoenvironment and organic matter enrichment mechanism of the Lucaogou Formation remain controversial.We studied the temporal evolution of the sedimentary paleoenvironment in the Lucaogou Formation by analyzing the elemental composition and total organic carbon content of 27 hydrocarbon source rock samples from the J305 well in the Jimsar Sag.Using these data,we found that the Lucaogou Formation overall was deposited in a semisaline to saline,reducing lake basin under an arid climate.We identified five organic matter-enriched intervals,which can be correlated with the parameters that indicate a wetter climate and a more anoxic lake environment.To compare sedimentary environments spatially,we compiled environmental indicators from 10 cores and outcrops in three sags around the Bogda Mountains.The compilation shows that the organic matter-enriched Jimsar Sag experienced a more arid climate and a more saline and anoxic lake environment during the deposition of the Lucaogou Formation,which was possibly controlled by the paleogeographic position.We conclude that the spatially arid climate and anoxic environment induced organic matter burial in the Jimsar Sag,while temporal events of a more humid climate and more anoxic environment triggered the enrichment of organic matter in some intervals of the Lucaogou Formation.

关 键 词：PALEOENVIRONMENT organic matter enrichment Lucaogou Formation Jimsar Sag Junggar Basin 

分 类 号：P618.13[天文地球—矿床学]