青藏高原白垩纪沉积见于６条东西向延伸的条带内。双壳类主要发育于这些条带的Ｂｅｒｒｉａｓｉａｎ，Ａｐｔｉａｎ－Ａｌｂｉａｎ，Ｃｅｎｏｍａｎｉａｎ－Ｔｕｒｏｎｉａｎ，Ｃｏｎｉａｃｉａｎ－Ｓａｎｔｏｎｉａｎ和Ｃａｍｐａｎｉａｎ－Ｍａａｓｔｒｉｃｈｔｉａｎ５个时期的地层。雅鲁藏布江缝合线为白垩纪双壳类地理分布的主要控制界线。早白垩世期间，雅鲁藏布江缝合带以南的喜马拉雅地区的双壳类Ｐｅｔｒｏｃｅｒａｍｕｓ，

The Cretaceous marine deposits in Qinghai Xizang Plateau develop mainly in six belts, extending from east to west. The fossil bivalves occur chiefly in five epoches, namely Berriasian, Aptian Albian, Cenomanian Turonian, Coniacian Santonian and Campanian Maastrichtian. Palaeobiogeographically, the Yarlung Zangbo River Suture Zone was the main controller for the distribution of the Cretaceous bivalves. During Early Creataceous, the bivalves Retroceramus, Nototrigonia, Maccoyella, Eyrena etc. emerging in the Himalayan area, south of the Yarlung Zangbo River Suture Zone, were similar to those contemporaries from Australia, Antarctica, East Africa and South America, belonging to the Gondwana Land; but Gervillaria, Caestocorbula, Myopholas, Trigonioides etc., from the north of the suture zone, were the elements limited in the northern margin of the Tethys and eastern Asian. Undoubtedly, there existed a deep and vast ocean, namely the Tethys Ocean, between the south and north of the suture zone then. In Late Cretaceous, the bivalves of these two areas gradually mixed as a result of the narrowing of Tethys Ocean. Up to Maastrichtian, the reef building rudists of warm water type, widespead in the Tethyan Realm since Late Jurassic, had emerged at last in the Himalayan Area, such as Bournonia, Praeradiolites, Biradiolites etc. According to the present materials, the bivalve biogeographical units are divided, and the northward drifting process of the Indian Subcontinent is expounded.

Q915.653

国家和中国科学院青藏研究项目