Preface Foreword On the Classification of the Sedimentary Facies-belts in the Yarlung ZangboXiangquan River Subsidence Region and their Sedimentary Models Wang Lien-cheng,Wang Tung-an 1.Description of some main Sections in this Region 2.Division of Sedimentary Facies-belts and Characteristics of eachFacies-belt 3.Sedimentary History of the Yarlung Zangbo-Xiangquan River Subsidence Region and the Sedimentary Model The Characteristics and Origin of Siliceous Rocks from Yarlung Zangbo Deep Fault Belt Wang Tung-an 1.Occurrence of Siliceous Rocks 2.Mineral Suite and Characteristics of Texture and Structure 3.Chemical Composition of Siliceous Rocks and its Property 4.Origin of Siliceous Rocks and Relation between it and the Plate Suture 5.Conclusions The Pebble Slates in Southern Xizang Wang Lien-cheng,Guo Shi-zeng 1.Introduction 2.Description of some Sections and Comparison of Stratigraphic levels 3.Petrologic Features of the Pebble Slates 4.Discussion on Origin of the Pebble Slates 5.Conclusions Plates