A novel model of the carbon cycle in the Cambrian ocean

作     者：Huajian WANG Shuichang ZHANG Xiaomei WANG Jin SU Yuntao YE Yuke LIU 

作者机构：Key Laboratory of Petroleum GeochemistryResearch Institute of Petroleum Exploration and DevelopmentChina National Petroleum CorporationBeijing 100083China Key Laboratory of Orogenic Belts and Crustal EvolutionSchool of Earth and Space SciencesPeking UniversityBeijing 100871China 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2024年第67卷第6期

页      面：1759-1778页

核心收录：

学科分类：070903[理学-古生物学与地层学(含：古人类学)] 0709[理学-地质学] 07[理学] 0708[理学-地球物理学] 

基　　金：financially supported by the National Natural Science Foundation of China(Grant Nos.42225303,42372162,42102146) the Basic and Forward-Looking Major Technology Projects of China National Petroleum Corporation(Grant No.2023ZZ0203) the National Key Research and Development Program of China(Grant No.2017YFC0603101) the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA14010101) 

主　　题：Carbon isotope Organic carbon BACE SPICE Dissolved organic carbon Climate change Black shale 

摘      要：The classic model of the carbon cycle suggests that the extensive burial of ^(12)C-enriched organic carbon leads to a positive carbon isotope(δ^(13)C)excursion(CIE),while massive oxidation of organic carbon results in a negative ***,global events such as the BAsal Cambrian Carbon isotope Excursion(BACE)and the Steptoean Positive Carbon Isotope Excursion(SPICE)are global negative and positive δ^(13)C excursions,respectively,and they also exhibit significant organic carbon burial anomalies,displaying decoupling between carbon isotope anomalies and organic carbon *** on the analyses of the Cambrian carbon cycle and paleoceanographic evolution records from well Tadong2 in the Tarim Basin,we propose a novel model of the carbon cycle in the Cambrian ocean that incorporates oceanic dissolved organic carbon(DOC).Our findings are as follows.(1)The Cambrian ocean maintained substantial DOC reservoirs,which were regulated by ocean currents and paleo-redox conditions and exerted significant influence on the oceanic carbon cycle.(2)The oxidation of the oceanic DOC reservoirs during the early Cambrian led to the BACE and the Asian Phenomenon of the Cambrian petroleum systems,while the expansion of the oceanic DOC reservoirs during the SPICE resulted in a global positive δ^(13)C excursion and the absence of significant organic carbon burial.(3)The deep-basin sedimentary environment in the eastern depression of the Tarim Basin may have fostered the development of organic-rich black shales during the Furongian Series,corresponding to organic carbon burial during the SPICE and representing potential prospects for ultra-deep oil and gas *** research should focus on the formation mechanism,reserve scale,and influencing factors of the oceanic DOC reservoirs,as well as their resource and environmental *** is expected that new breakthroughs will be made in the fields of Earth system science and oil and gas exploration.