青藏高原尼玛盆地东部古近系昆虫化石的发现及其对古气候的指示  

The discovery of Paleogene insect fossils in eastern Nima Basin,Tibet,and its implication for paleoclimate

作　　者：曾胜强[1,2] 陈文彬 付修根[4] 刘君豪 李金锋 仇季龙 ZENG Shengqiang;CHEN Wenbin;FU Xiugen;LIU Junhao;LI Jinfeng;QIU Jilong(Chengdu Center of China Geological Survey,Chengdu 610081,Sichuan,China;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,Sichuan,China;Key Laboratory for Sedimentary Basin and Oil and Gas Resources,Ministry of Natural Resources,Chengdu 610081,Sichuan,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,Sichuan,China;280 Institute of Nuclear Industry,Guanghan 618300,Sichuan,China)

机构地区：[1]中国地质调查局成都地质调查中心,四川成都610081 [2]成都理工大学沉积地质研究院,四川成都610059 [3]自然资源部沉积盆地与油气资源重点实验室,四川成都610081 [4]西南石油大学地球科学与技术学院,四川成都610500 [5]核工业二八○研究所,四川广汉618300

出　　处：《地质通报》2020年第7期1121-1124,共4页Geological Bulletin of China

基　　金：中国地质调查局项目《西藏羌南—措勤地区油气地质调查》(编号:DD20190116);国家自然科学基金项目《北羌塘盆地东部晚三叠世—早侏罗世沉积转换研究——来自地质浅钻岩芯记录的证据》(批准号:41702119)。

摘　　要：藏北尼玛盆地自白垩纪以来沉积了巨厚的陆相碎屑岩夹灰岩地层,由于缺乏生物化石证据,其地层时代一直存在较大的争议。最近,在尼玛盆地东部赛布错一带的细碎屑岩夹灰岩地层中发现大量的昆虫、鱼类和植物化石。昆虫化石主要为伦坡拉大黾蝽Aquarius lunpolaensis,与伦坡拉盆地达玉地区和尼玛盆地西部江弄淌噶地区报道的种属形态特征基本一致,显示该套地层为晚渐新世丁青湖组沉积,而不是竟柱山组或牛堡组。另外,伦坡拉大黾蝽主要生活在温暖湿润的低海拔地区,结合近年在青藏高原中部伦坡拉盆地和尼玛盆地晚渐新世地层中发现的热带-亚热带鱼类和大植物化石组合,指示青藏高原腹地在晚渐新世为温暖湿润的低地环境,而不是过去认为的高寒气候。Since the Cretaceous period,thick terrigenous clastic rocks interbedded with limestone strata have been deposited in the Nima Basin,northern Tibet,but the deposition age is still debatable due to the lack of fossil evidence.Recently,a lot of insect,fish and plant fossils were discovered from the fine clastic rocks interbedded with limestone strata in the Saibu Co area in the east of the Nima Basin.The insect fossils mainly consist of Aquarius lunpolaensis,which is consistent with the morphological characteristics of the species reported in the Dayu area in the Lunpola Basin and the Jiangnongtangga area in the west of Nima Basin,indicating that this set of strata was Late Oligocene Dingqinghu Formation rather than the Jingzhushan Formation or Niubao Formation.In addition,Aquarius lunpolaensis mainly existed in warm and humid environment at low elevation area and,in combination with tropical to subtropical fish and plant fossil assemblage in the Late Oligocene strata in the Lunpola and Nima basins of central Tibet found in recent years,the authors argue for a warm and humid lowlands environment in the Late Oligocene period in the central Tibet rather than high and cold climate as used to be considered.

关 键 词：昆虫化石 晚渐新世 丁青湖组 尼玛盆地 

分 类 号：P634.61[天文地球—地质矿产勘探] Q915[天文地球—地质学]