【作者】 万晓樵；

【Author】 Wan Xiaoqiao (Beijing Graduate School,Wuhan College of Geology)

【机构】 武汉地质学院北京研究生部；

【摘要】 <正>中国海相白垩系主要分布于西藏大部及新疆塔里术西沿,由于受环境因素控制,各地有孔虫发育情况不同。西塔里木属于海湾及泻湖环境,生存有底栖小有孔虫动物群;西藏雅鲁藏布江以北的广大地区在白垩纪中期处于滨浅海环境,繁盛着圆笠虫动物群;雅鲁藏布江以南为广海环境,据沉积环境又可进一步分成南北两个相带,南带属于正常浅海陆棚环境,有孔虫动物群是浮游与底栖的混合类型;北带属于较深海环境,生存着浮游有孔虫更多还原

【Abstract】 The marine Cretaceous succession of Xizang(Tibet)is discussed,with emphasis on the planktonic foraminifera.The Lower Cretaceous is poor in plank- tonic foraminifera.Single-keeled Rotalipora faunas characterize the Middle Cretaceous,and single-keeled and double-keeled Globotruncana faunas typify the Upper Cretaceous.Radiometric data and phylogenetic analysis of the Cre- taceous planktonic foraminifera suggest the phylogenetic lines.The Cretaceous deposits of Xizang are divided into eleven planktonic foraminitera zones rang- ing in age from Albian to Companian.These zones are designated by their ch- aracteristic species,which are restricted to respective zones.They can be corre- lated with the zones of Pakistan and those of Europe and America.更多还原