路1%张 2012年2月
代地质现
GEOSCIENCE
西藏南部岗巴地区白垩纪化石碳酸盐岩
微相与沉积环境研究
刘云龙，李国彪
（中国地质大学地球科学与资源学院，北京100083）
Vol 26 Na. 1 Feb.2012
摘要：西藏南部岗巴地区发育着我国最完整的海相白垩纪地层，对该时期海相沉积演化特征的研究，能够较好地反映该地区在印度板块和欧亚板块磁擦前的演化信息。对白垩纪岗巴地区的化石碳酸盐岩微相进行了较为详细和系统的分析与研究。初步识别出12种微相和7种生物相类型，在此基础上对西特提斯白垩纪沉积环境的演变进行了初步的探讨。西藏特提斯在白垩纪的海水进退规程总体上表现为：Berriasian—Aptian期发生海侵，Albian早期发生海退，Albian 晚期—Cenomanian期水体有进一步加深的趋势，Turonian期再次发生大规模海侵，Santonian-Coniacian期海侵持续进行，Maastrichtian期海水急剧变浅。
关键调：西藏特提斯；白墨纪；有孔虫动物群；碳酸盐岩微相；沉积环境
中图分类号：P534.53
文献标志码：A
文章编号：10008527(2012)01-0022-14
MicrofaciesandSedimentaryEnvironmentsofCretaceous
FossilCarbonatein Gamba,SouthernTibet
LIU Yun-long,LI Guo-biao
(School of Earth Sciences and Resources, China Uninersity of Geociences, Beijing100083, China)
Abstract: Cretaceous marine strata are well exposed in Gamba, southem Tibet, and the study of which may provide abundant information about the evolution of Tibet-Tethyan ocean before the collision between Indian and Asian plates. This research carried out a detailed study on the Cretaceous fossil carbonate microfacies of Gam-ba. Twelve types of microfacies (MF1-MF12) and seven types of biofacies had been recognized. On the basis of these, the research made a preliminary discussion on the environmental evolution of Tibetan-Tethys during Cre taceous, which could be concluded as follows: a transgression took place during the Barremian-Aptian; in the early of Albian, Gamba area was generally in a regressive environment; from the Late Albian to Cenomanian the seawater had a deepening trend; there was a big transgression which took place during the Turonian and lasted to Santonian-Coniacian; the seawater became shallow rapidly during the Maastrichtian.
Key words: Tibetan-Tethys; Cretaceous; foraminifera; carbonate microfacies; sedimentary environment
引言 0
发生许多重大地质事件，如大洋缺氧事件（Oceanic AnoxicEvent，OAE）、大洋富氧事件（白垩纪大洋
白垩纪是地质历史上一个重要时期，该时期红层CORBs）、大火成岩省（LargeIgneousProv-收稿日期：2011-08-25；改回日期：2011-10-20；责任编辑：令枝。
基金项目：国家"973"计划项目（2012CB8220001）；国家自然科学基金项目（40972028）；中国地质大学（北京）优秀教师研究项
（53200959212)。
作者简介：刘云龙，男，本科生，1988年出生，古生物学与地层学专业，主要从事微体古生物与地层的研究工作。
Email;lyl007t@163.eom
通信作者：李国题，男，教授，博士生导师，1968年出生，古生物学与地层学专业，主要从事地层古生物学的科研和教学工
作。Email;shaowuren@tom.com。