天山造山带地壳结构与构造──乌鲁木齐─库尔勒地震转换波测深剖面

沿乌鲁木齐－库尔勒３５０余公里长的测线上完成了穿越天山的地震转换波野外观测，得出天山造山带的深部构造剖面图和壳内Ｐ，Ｓ波速度结构模型．天山的结晶地壳可分为４层，各层的速度分别是：Ｖｐ值为５．９，６．３，６．６，６．９ｋｍ／ｓ；Ｖｓ值为３．２，３．５，３．７，３．９ｋｍ／ｓ。上地幔顶部的波速：Ｖｐ值为８．１０ｋｍ／ｓ。Ｖｓ值为４．６ｋｍ／ｓ。天山地区的地壳厚度为４２－５６ｋｍ，中天山最厚，达到５０－５６ｋｍ。地壳中部存在低速透镜体。探测结果表明，天山大地构造可分为北天山、中天山和南天山３个区，其地壳深部构造特征各不相同。用颤动构造理论来解释天山造山带的形成机制和演化较板块构造理论更为合理。

THE CRUST STRUCTURES OF TIANSHAN OROGENIC BELT: A DEEP SOUNDING WORK BY CONVERTED WAVES OF EARTHQUAKES ALONG RMQI-KORLA PROFILE

A deep-sounding observations by using the PS converted waves of the earthquakes along the rmqi-Korla profile across the Tianshan mountains have been conducted with the cooperation efforts of Chinese, Kazakhstan and Kirghizstan scientists in 1992. As a results a cross-ection of deep crust structures and the velocity models of P and S waves along the profile were obtained. The consolidate crust of the Tianshan mountains is consisted of 4 layers with the velocities of Vp=5.9km/s, 6.3km/s, 6.6km/s, 6.9km/s, Vs=3.2km/s, 3.5km/s, 3.7km/s, 3.9km/s. The velocities of the top of the upper mantle are: Vp = 8.1km/s and Vs=4.6km/s. The thickness of the crust is ranging between 42km and 56km. The maximum thickness of the crust in middle Tianshan reaching to 53-56km. There are some low-velocity lens in the middle part of the crust. The results show that the Tianshan mountains are divided into three tectonic zones: northern, central and southern Tianshan, different in the characteristics of the deep crustal structures, and it seems that the formation and the evolution of the Tianshan mountains can be explained with the theory of Surge Tectonics-a new hypothesis of Earth dynamics more resonably then the theory of Plate Tectonics.