Depositional Process and Mechanism of Organic Matter Accumulation of Lucaogou Shale in Southern Junggar Basin, Northwest China
Zhang Xun
Zhuang Xinguo
Tu Qijun
Xu Shiqi
Zhang Ya
Abstract：The lacustrine shale succession of the Permian Lucaogou Formation in southern Junggar basin,Northwest China,is the most important hydrocarbon source rock and an unconventional reservoir.However,there are relatively few studies on the deposition process of Lucaogou shale,the hydrologic conditions controlled by the paleoclimate,and the enrichment mechanism of organic matter in the shale.In this study,the Lucaogou shale was studied comprehensively,based on the results of its sedimentological and geochemical test data.Results show that the Lucaogou shale was deposited in a semi-deep to deep stratified lake,which has anoxic,highly saline bottom and oxic,less saline surface water.The lake catchment of the study area has climatic zonality,which presents as that the paleoclimate in the lake catchment of northeastern Bogda was warm and humid and the paleoclimate in the lake catchment of western Bogda was arid.Elevated precipitation in humid climate provides fresh water rich in nutrients to lake caused relatively high paleoproductivity and promotes lake stratification,which led to relatively high TOC in the Lucaogou shale of northeastern Bogda.Organic matter accumulation in the Lucaogou shale was influenced by surface water primary productivity and preservation in stable anoxic bottom water.
Keywords：Junggar basinLucaogou Formationshalepaleoclimateorganic matterpetroleum geology
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：13( 538-550 )