STRUCTURAL AND SEDIMENTARY FEATURES OF TWO TYPES OF MESOZOIC CONTINENTAL MARGIN IN SOUTHERN XIZANG （TIBET）

Two major types of late Mesozoic continental margin can be distinguished in southern Xizang. One is the Pacific-type （active） continental margin characterized by a typical trench-arc system at the northern side of the Yarlung Zangbo suture,and the other is the Atlantic-type （stable） continental margin characterized by continental shelf-slope-rise at the southern side. Their structural and sedimentary units are differnt, as shown in the following table: This paper further discusses the characteristics of sedimentary, formations,tectonic deformation and evolution history of either enviroment according to the data of stratigraphic, sedimentary facies, paleontology, paleomagnetism and isotope geochronology.