塔里木盆地库车河剖面有机碳同位素地层学及三叠系—侏罗系界线  

Organic Carbon Isotope Stratigraphy in the Kuqa River Section,Tarim Basin,and the Corresponding Triassic-Jurassic Boundary

作　　者：方琳浩 彭博 邓胜徽[4] 卢远征[4] 张新智 邱若原 彭佳里 张小宇 鲜本忠[1,2] 师生宝[1,2] FANG LinHao;PENG Bo;DENG ShengHui;LU YuanZheng;ZHANG XinZhi;QIU RuoYuan;PENG JiaLi;ZHANG XiaoYu;XIAN BenZhong;SHI ShengBao(College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum(Beijing),Beijing 02249,China;PetroChina Hangzhou Research Institute of Geology,Hangzhou 310023,China;Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China;Cores and Samples Center of Natural Resources,CGS,Sanhe,Hebei 065201,China)

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]中国石油杭州地质研究院,杭州310023 [4]中国石油天然气股份有限公司勘探开发研究院,北京100083 [5]中国地质调查局自然资源实物地质资料中心,河北三河065201

出　　处：《沉积学报》2022年第6期1635-1648,共14页Acta Sedimentologica Sinica

基　　金：国家自然科学基金(41502024);中国石油大学(北京)青年拔尖人才项目(2462014YJRC027)。

摘　　要：三叠纪—侏罗纪之交发生了地史上五次最大规模之一的生物灭绝事件、中大西洋大火成岩省喷发、泛大陆进一步裂解导致的中大西洋开启以及大气CO_(2)浓度急剧升高等。然而该时期中国各板块主要发育陆相沉积,其三叠系—侏罗系界线(TJB)很难与定义于海相地层的全球层型剖面和点(GSSP)进行精细对比。应用基于C3植物的碳同位素地层学,进行了两次独立地、系统地以高等植物木质部为研究对象的采样和测试,获得了可以指示同期大气CO_(2)的δ^(13)C演化和进行全球等时对比的碳同位素地层曲线。并在植物大化石和孢粉的生物地层约束基础上,首次完成了库车河剖面与海相三叠纪末期生物大灭绝事件(ETE)底界和TJB的精细对比;推测与全球其他剖面ETE等时的地层界线位于38层底部附近,与TJB的GSSP等时地层界线位于41层底部附近。海相与陆相的ETE和TJB层位附近均出现了δ13C负偏,指示全球性的碳同位素的波动,推论该时期发生了全球规模的、地表圈层的碳储库扰动。The boundary between the Triassic and Jurassic periods is a key moment in Earth history,which is distin⁃guished by one of the five biggest mass extinctions,Pangea progressively breaking apart with the opening of the cen⁃tral Atlantic Ocean,eruption of Central Atlantic Magma Province,and a dramatic increase in the CO_(2) concentration.However,the major occurrence of terrestrial sediments in China has been difficult to bio-stratigraphically correlate with the Global Stratotype Section and Point(GSSP)defined in marine strata from the Triassic-Jurassic boundary(TJB).Two new δ^(13)C wood stratigraphic curves in the Kuqa River section were generated from two independent sam⁃plings,focusing on the materials within the charcoal and coalified fossil wood and representing the synchronous evolu⁃tion of δ^(13)C in atmospheric CO_(2).The consistency of the two results proves the repeatability of this study,verifying the method of carbon-isotope stratigraphic sampling.The terrestrial Kuqa River section in the Tarim Basin is well correlat⁃ed with the TJB of GSSP in Austria and other typical global sections,as constrained by the biostratigraphy of sporopollen assemblages and mega-plant fossils.The end-Triassic mass extinction(ETE)beginning horizon and synchro⁃nous TJB of GSSP are located near the bottom of Beds 38 and 41,respectively.The obvious negative carbon isotope excursion took place at the of the ETE beginning horizon and TJB.The significant fluctuations of carbon-isotope re⁃cords in both marine and terrestrial strata across the ETE and TJB have been discovered globally,suggesting a global perturbation of carbon reservoirs within Earth surface cycles during this period.

关 键 词：三叠系—侏罗系界线 生物大灭绝 地层对比 碳同位素地层学 塔里木盆地 

分 类 号：P539[天文地球—古生物学与地层学]