西藏札达盆地形成演化与喜马拉雅山隆升

The Formation and Evolution of Zhada Basin in Tibet and the Uplift of the Himalayas

通过野外地质调查、实测地层剖面和室内综合研究,笔者将札达盆地上新世-早更新世形成演化划分为6个阶段:①盆地初始断陷阶段;②盆地加速断陷阶段;③盆地强烈断陷阶段;④盆地断陷止息阶段;⑤盆地二次初始断陷阶段;⑥盆地二次加速断陷阶段.并以札达盆地形成演化为基础将喜马拉雅山此阶段的隆升划分为5个阶段:①慢速隆升阶段(5.4～4.4Ma);②中速隆升阶段(4.4～3.5 Ma);③快速隆升阶段(3.5～3.2Ma);④停止隆升阶段(3.2～2.7 Ma);⑤快速隆升阶段(2.7Ma).研究表明,喜马拉雅山的隆升是一个多阶段、不等速和非均变的复杂过程.

According to field geological investigation, stratigraphic section survey and indoor integrated studies, the authors have divided the evolution of Zhada basin during Pliocene_Early Pleistocene into six stages, namely, ① the initial fault depression, ② the accelerated fault depression, ③ the intense fault depression, ④ the stop of fault depression, ⑤ the second initial fault depression and ⑥ the second accelerated fault depression. On the basis of the shaping and evolution of Zhada basin, the uplift of the Himalayas has been divided into five stages, i.e., ① the slow uplift stage (5.4～4.4 Ma), ② the intermediate_speed uplift stage (4.4～3.5 Ma), ③ the high_speed uplift stage (3.5～3.2 Ma), ④ the stop of the uplift (3.2～2.7 Ma) and ⑤ the fast uplift stage (2.7 Ma). It is obviously shown that the uplift of the Himalayas is a complex process characterized by poly_stages, nonuniform velocity and nonuniformity.