西藏改则盆地晚始新世康托组介形类动物群及地质意义  

THE OSTRACOD FAUNA AND ITS GEOLOGICAL SIGNIFICANCE FROM THE LATE EOCENE KANGTUO FORMATION,GAIZE BASIN,SOUTHERN TIBET PLATEAU,CHINA

作　　者：姜高磊[1,2] 袁爱华[1,2] 张克信[1,2,3] 

机构地区：[1]中国地质大学(武汉)生物地质与环境地质国家重点实验室,武汉430074 [2]中国地质大学(武汉)地球科学学院,武汉430074 [3]中国地质大学(武汉)地质调查研究院,武汉430074

出　　处：《微体古生物学报》2014年第4期405-419,共15页Acta Micropalaeontologica Sinica

基　　金：中国地质调查局项目(编号:1212011121261);大学生自主创新计划(编号:1410491A04)联合资助

摘　　要：西藏改则盆地新生代陆相康托组地层发育,记录了青藏高原腹地始新世气候变化和隆升历史。本文通过对改则盆地中南部改则县嘎热村康托组剖面进行系统的采样和室内处理,获得363个介形类个体,共鉴定11属27种(包括1个未定种)。通过研究区介形类动物群的特征分子Heterocypris igneus及与东濮、渤海、华北、江汉等地区介形类动物群对比研究,认为康托组上部的沉积时代应为晚始新世。本文首次报道了改则盆地康托组的介形类动物群面貌,据介形类组合厘定了康托组沉积时代,为研究青藏高原腹地新生代地层提供了基础资料。The Kangtuo Formation （Fm.） composed of sandstones, siltstones and mudstones, is mainly of Cenozoic lacustrine facies sediments in the Gaize Basin. It is an important record for the study of the Cenozoic climate and uplift history of the southern Tibet Plateau. However, the exact sedimentary age of the Kangtuo Fm. has been controver- sial. Ostracoda is an usable tool to indicate the geological time especially when other fossils are absent. In this study, 27 ostracod species （including 1 indetermined species） belonging to 11 genera are described from the Kangtuo Fro. It is the first report of.ostracod fauna from the lacustrine sediments of the Kangtuo Fro. in the hinderland of Tibet Pla- teau. In this fauna, Heteroeypris igneus is the dominant species and has high abundance in the upper part of the stu- died section. This species haS been reported from the Shahejie Fro. in Dongpu and Bohai area, the Dainan Fro. in Jiang- su Province, ahd the K6ngdian Fro. in North China, which indicates a Late Eocene age. Therefore the Upper Kang- tuo Formation could be deposited at the Late Eocene, which provides significant clue for further study on the CenOzoic stratigraphy of the southern Tibet Plateau.

关 键 词：介形类 康托组 晚始新世 改则盆地 西藏 

分 类 号：Q915[天文地球—古生物学与地层学]