川西藏东板块构造体系及特提斯地质演化

川西藏东可划分为巴颜喀拉、羌塘和拉萨3个板块构造体系。每个体系由结合带、岛弧褶皱带、弧后盆地褶皱带和盆后隆起组成。它们是在晚二叠世冈瓦纳古陆和劳亚古陆沿巴塘拼合带碰撞拼合的基础上，自ＮＥ而ＳＷ经历了三叠纪巴颜喀拉板块构造体系的形成、株罗纪羌塘板块构造体系的形成和白垩纪拉萨板块构造体系的形成以及新生代以来陆－陆碰撞造山和高原隆升而逐渐形成的。

Plate Tectonic Systems and Tethys Geologocal Evolution in Western Sichuan and Eastern Tibet

The western Sichuan and eastern Tibet region is located in the turning position where the east west trending eastern Tethys tectonic domain changes to be the north-south trending one.There arethree plate tectonic systems in this region,i.e.The Bayan Har,Qiangtang and Lhasa plate tectonicsystems,each consisting of a suture zone,an island-arc fold belt,a back-arc basin fold belt,and aback-basin rise.The tectonic framework of this Tethys domain was formed via five stages of geological cvolution:1.collision of the Geondwana land and Laurasia land along the Batang suture zone during the LotePermian;2.floor sprcading of the Jinshajiang Tethys Sea,subouction of the oceanic crust,and conti-nent-continent collision,which resulted in the Bayan Har plate tectonic system during the Triassic pe-ried;3.floor sprcading of the Nujiang Tethys Sea,subduction of the oceanic crust,and continent continent collision, which led to for mation of the Qiangtang plate tectonic system during the Jurassicperiod;4floor spreading of Yarlung Zangbo Tethys Sea,sutxluction of the oceanic crust,and conti-nent-continent collision,which brought about forming the Lhasa pfate tectonic system during the Cre-taceous-Eocene;5.intracontinental convergence and uplifting of the Qinghai-Tibet plateau during theCenozoic Era.It has been suggested that the plateau was fotmd under the northward complessive stress exted bythe Indea plate,through three stages:1. thickening of the lower and middle crust of the overridingptates caused by the subduction of the oceanic crust mainly during the Cretaceous-Eocene;2.folding,faulting and orogeny which made the upper crust of the overriding plates shortened and thickenedmainly during the Oligocene-Miocene;3.Overall uplifting of the plateau since the Pliocene.