The Research About Foeaminiferal In The Upper Cretaceous In Gangba Qiang Dong Area, South Tibet

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.