青藏特提斯沉积地质演化

<title>Sedimentary geological evolution of the Qinghai-Xizang Tethys

组成青藏高原的主要微板块在不同的阶段经历了各具特色的地质演化历程和发展特点,形成了不同的地壳结构。青藏高原的沉积地质历史演化经历了区内各主要微板块的基底形成与盖层沉积演化的前特提斯阶段;以板块汇聚边缘与碰撞时期的构造背景为基础,划出古特提斯、中特提斯和新特提斯三个沉积地质历史发展及其所形成的弧盆体系格架的特提斯形成演化阶段;随着始新世末期残留海的消失,青藏地区形成统一大陆,并进入统一应力场的青藏统一陆壳形成阶段;从中上新世开始的青藏高原隆升阶段,青藏高原上发育了一些大中型中新生代沉积盆地,如羌塘盆地、措勤盆地、昌都盆地等都经历过从弧后盆地向前陆盆地转化的演化阶段,并具有受喜马拉雅运动统一改造的特征,这些沉积盆地中油气藏前景良好。

<Abstrcat> The historical evolution of sedimentary geology of the QinghaiXizang Plateau is involved in: (1) the PreTethys stage, when the basement and cover of individual microplates were initiated; (2) the Tethys stage that may be divided into Palaeo, Meso and NeoTethys stages, when the frameworks of arcbasin systems were developed; (3) the formation of the Plateau continental crust with the collapse of the residual seas and unified stress fields during the latest Eocene, and (4) the formation and uplift of the Plateau since the Miocene and Oligocene. Some large or mediumsized Mesozoic and Cenezoic basins on the Plateau such as Qiangtang, Coqen and Qamdo basins were once evolved from backarc basins to foreland basins and reworked without exceptions by the Himalayan orogeny, and thus have the potential of oil and gas resources.