Foraminiferal Biostratigraphy Of The Cretaceous Oceanic Red Beds In Eastern Zhilong,Gyangze,Tibet

Cretaceous is a typical representative of the extreme greenhouse climate in geological history, which has long been regarded by the international earth science community as a case study of Earth System Science for a long period. The best Cretaceous marine strata in China is outcropped in Southern Tibet, which yields abundant microfossils such as foraminifera, and therefore is the ideal place to study Cretaceous marine biostratigraphy.During Cretaceous, Northern Tethyan Himalaya subzone(Kangmar- Gyangze)was located in a slope-basin environment with relatively deep water. The Cretaceous Oceanic Red Beds(CORBs) were widespread in northern subzone. CORBs usually contain few macrofossils, but yield abundant microfossils especially such as foraminifera and radiolarians. Therefore the study of microfossils is particularly important for us to determine the age and paleoecology of the CORBs. This thesis focuses the study on the planktonic foraminiferal biostratigraphy of the CORBS well-exposed in Eastern Zhilong section, Suojin, Gyangze, southern Tibet.Chuangde Formation in Eastern Zhilong Section contains abundantplanktonic foraminifera by studies.By systematic identification and study on the foraminifera of Eastern Zhilong Section, 85 species of 27 genera are indentified and 3 foraminiferal zones have been recognised from the CORBs: Globotruncanita elevate Zone, Globotruncana ventricosa Zone, Radotruncana calcarata Zone.Foraminiferal biostratigraphic sequence of the CORBs is initially built up bythe characteristics of foraminiferal assemblages in Eastern Zhilong Section, and the Planktonic foraminiferal fauna provides a Campanian age for the CORBs in the study area.