【作者】 高茂龙；

【导师】 李国彪；

【作者基本信息】 中国地质大学（北京） ， 古生物学与地层学， 2011， 硕士

【摘要】 白垩纪是地质历史中的一个极为特殊的时期,介于侏罗纪和古近纪之间,是中生代的最后一个纪。在白垩纪时期,无论是无机界还是有机界都经历了重要变革,发生了众多重大地质事件。因此,白垩纪被认为是地史时期地球系统研究的典型范例时期。在西藏南部,我国的海相白垩纪地层广泛分布在特提斯—喜马拉雅带。从上世纪初开始,国外学者开始对这一地区加大研究力度。新中国成立之后,我国逐步建立起详细的地层系统。但随着国外相关研究精度的提高以及新技术的不断出现,有必要重新对藏南海相白垩系地层进行高精度的浮游有孔虫生物地层研究。本次研究在强东剖面中采集的样品中获得大量的有孔虫化石,共鉴定出有孔虫有58属、121种。其中浮游类型属有15个,浮游类型种有74个;底栖类型属有43个;底栖类型种有47个。根据强东剖面有孔虫的特征,参考白垩纪浮游有孔虫标准化石带,并通过与西藏特提斯其它地区资料的对比,本文对强东剖面进行了有孔虫化石带的划分,共识别出11个有孔虫化石带,自下而上分别是Rotalipora subticinensis,R. ticinensis带,R. appenninica带,R. reicheli带,R. cushmani带,Whiteinella archeocretacea带,Helvetoglobotruncana helvetica带,Marginotruncana sigali带,Dicarinella primitiva带,D. concavata带,D. asymetrica带,Globotruncanita elevata带,Globotruncana ventricosa带。结合前人的研究成果,并通过与其它地区进行对比,本文初步建立起研究区的有孔虫生物地层序列,从而为研究西藏特提斯洋的演化过程及期间发生的重大地质事件打下了一个较好的基础。最后,本文根据浮游有孔虫化石鉴定结果试对西藏定日地区晚白垩世古地理演化进行了探讨。更多还原

【Abstract】 The Cretaceous is a special period between Jurassic and Paleogene in the geological history. A significant change happened in organic and inorganic world during Cretaecous,aacompanying with many major geological events. Therefore,the Cretaceous period was considered as a classical example for earth system research of geologic history period. The Cretaceous marine strata are well exposed in South Tibet and the stratigraphic framework has been established. With the improvement of related research resolution overseas and accumulation of plenty of new date are the necessity and importance of high precision planktonic foraminiferabiostratigraphic research is gradually increasing.In this work,aboundant foraminiferal fossils have been gained from the samples of the Qiangdong section of Gamba. Identified plantic foraminifera include 15 genus and 74 species,and benthic foraminiferas include 43 genus and 47 species. According to the distributional character of the foraminiferal fossils from the Qiangdong section,comparising them with the foraminiferal data from other areas of Tibetan Himalaya,eleven foraminiferal zones are established from the Qiangdong section,which are Rotalipora subticinensis,R. ticinensis,R. appenninica,R. reicheli,R. cushmani,Whiteinella archeocretacea,Helvetoglobotruncana helvetica,Marginotruncana sigali,Dicarinella primitiva,D. concavata,D. asymetrica,Globotruncanita elevata,and Globotruncana ventricosa zones. Comparising the research about this paper and other predecessors’ achievements in this area,we can establish the relatively complete spatio-temporal framework for research,thus defining the late cretaceous’ stratum. The formation boundary for other accurately dividing and global contrast to lay a solid foundation.更多还原