西藏羌北—昌都地区三叠纪岩石地层及印支运动

TRIASSIC LITHOSTRATIGRAPHY AND INDOSINIAN MOVEMENT IN THE QANGBEI QAMDO AREA,TIBET

摘要: 西藏羌北—昌都地区地处阿尔卑斯—喜马拉雅构造域东段弧形转弯部分，位于“劳亚大陆”与“冈瓦纳大陆”之间，是一个具有过渡性质的中间陆块，即常被称为“三江褶皱系”。羌北—昌都地区属于“褶皱系”的北段，其岩石地层、生物地层、岩浆活动、火山作用、构造运动、地壳变形变质作用等方面都具有独立的特征，但与周围也具有诸多的联系。从现代地层学、沉积学的观点研究认为，羌塘—昌都地区的印支运动主要受到３个区域性构造运动界面的控制，形成两个主要的构造层，属于印支运动的主幕有两期。印支期的海水进退、岩石地层沉积、岩浆火山活动、变形变质作用与成矿作用等都可分属这两期构造运动的产物。

Abstract: This paper discusses two Triassic transgression events,Triassic lithostratigraphy and Indosinian movement in the Qangbei Qamdo area,Tidet.Modern stratigraphic and sedimentologic studies suggest that during the Indosinian movement in the Qangtang Qamdo area was mainly controlled by three boundries of regional tectonic movements,forming two structural layers.Only two stages belonged to the main phase of the Indosinian movement.All the Indosinian sea transgressions and regressions,sedimentation,magmatism and volcanism,deformation metamorphism and mineralization are products of the two stages of tectonic movements.