关键词: 转换波, 深部探测, 速度结构, 塔里木

Abstract: A deep sounding survey by the method of converted waves of earthquakes has been completed along the Kuche Tazhong Tanan profile in the central part of the Tarim Basin. The lithosphere of study region is characterized by the layered blocked structures with the crustal thickness about 40～50km. The crustal thickness is about 40km in the uplifted region and it is about 50km in the subsided region. The upper crust (the granitic gneiss layer) is obviosely thinning to the central part of the Tarim Basin. The velocity of the middle crust is relatively high( V_P= 6.4 ～6.5km/s, V_S=3.4～3.5km/s). There are some thin low velocity layers in the upper part of the lower crust. The average velocity of the crystalline crust of the Tarim basin is higher than the surrounding Qing Zhang plateau and Tianshan mountain regions. The velocity structures of the basin show its continental crust character. All the data of the investigation show that since the Cenozoic Era under the action of strong compression force from the India plate,the quasi synchronous bend deformation of all lithospheric layers and the adjusted movement of the rigid crust blocks along the deep sited faults may be the main deep dynamic processes in the lithosphere of the Tarim basin.

Key words: Converted wave, Deep sounding, Velocity structure, Tarim