察尔汗钻孔介形类记录及其对察尔汗古湖晚更新世高湖面的指示  

Ostracod records from a drill core in the Qarhan and its implications for Late Pleistocene high lake level in paleo-lake Qarhan

作　　者：宋博文[1,2] 柯学[1,2] 宋泰忠 张克信[1,2] 杨文军 张金明[3,4] 张小瑾[3,4] SONG Bowen;KE Xue;SONG Taizhong;ZHANG Kexin;YANG Wenjun;ZHANG Jinming;ZHANG Xiaojin(Institute of Geological Survey,China University of Geosciences,Wuhan,Hubei 430074,China;State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan,Hubei 430074,China;Qinghai Geological Survey Institute,Xining,Qinghai 810012,China;Qinghai Provincial Key Laboratory of Geological Processes and Mineral Resources of Northern Qinghai-Tibet Plateau,Xining,Qinghai 810012,China)

机构地区：[1]中国地质大学(武汉)地质调查研究院,湖北武汉430074 [2]中国地质大学(武汉)生物地质与环境地质国家重点实验室,湖北武汉430074 [3]青海省地质调查院,青海西宁810012 [4]青海省青藏高原北部地质过程与矿产资源重点实验室,青海西宁810012

出　　处：《地质学报》2023年第10期3168-3179,共12页Acta Geologica Sinica

基　　金：青海省地质矿产勘查开发局地质勘查项目(编号青地矿科[2022]32号);中国地质调查局项目(编号DD20221645);国家自然科学基金项目(编号42072141)联合资助的成果。

摘　　要：察尔汗盐湖作为柴达木盆地第四纪的沉积中心,沉积了巨厚的第四系湖相沉积,其演化历史研究对于揭示柴达木盆地及青藏高原北部第四纪古气候、古环境演变历史具有重要意义。本文在AMS^(14)C测年的基础上,以察尔汗盐湖晚更新世钻孔(ZK53630-1)岩芯中介形类微体化石为研究对象,通过系统的采样和室内分析,共识别出7属10种。基于分类学研究,识别出2个介形类组合(自下而上):Ilyocypris biplicata-Limnocythere inopinata和Ilyocypris bradyi-Ilyocypris sebeiensis。介形类及其伴生化石均显示察尔汗古湖在距今34~28 ka期间的晚更新世晚期(MIS 3a)主体为淡水—微咸水湖泊,气候温暖湿润,与现今极端干旱的盐湖环境截然不同。The Qarhan salt lake is the depocentre of the Qaidam basin during the Quaternary,with a very thick sequence of lacustrine sediments.Continuous lacustrine sediments provide excellent archives of detailed paleo-environmental data regarding climatic change in the Qaidam basin and northern Tibetan Plateau.In this study,fossil ostracods from the drill core(ZK53630-1)sediment were analyzed in conjunction with AMS^(14)C dating.A totalof 10 ostracod species belonging to 7 genera are identified.The ostracod fauna can be subdivided into two assemblages from bottom to top:Ilyocypris biplicata-Limnocythere inopinata and Ilyocypris bradyi-Ilyocypris sebeiensis.The ostracod fauna and associated micro-fossils suggest the existence of a large freshwater to oligohaline lake in the Qarhan area during the Late Pleistocene(MIS 3a,34~28 ka),coevaled with a warm and humid climate,which was completely different from the present-day hyper-arid salt lake environment.

关 键 词：介形类群落 察尔汗古湖 柴达木盆地 MIS 3阶段 古环境 

分 类 号：P532[天文地球—古生物学与地层学]