Abstract: The Tuotegongbaizi-Aerpaleike fault is located in the epicentral area of the 1902 Artux,Xinjiang earthquake of M S 81/4. It is a gently dipping reverse fault, merging downward into the decollement of South Tianshan Foreland Thrust belt at about 3km depth below the Earth surface. To the north of the epicentral area, lies the Muziduke thin-skinned arcuate nappe of the South Tianshan Foreland Thrust belt, while to the south lies the Mushi-Kashi-Artux arcuate recoil fold-thrust belt of northwest Tarim. The epicentral area is just located at the triangle zone of frontal structure of the juncture between these two major tectonic units. In the epicentral area a deep fault exists under the decollement of the thin-skinned nappe, extending downward to the Moho. It is located at the sharp gradient zone of the crust-mantle boundary between the South Tianshan and the Tarim basin. The projection of epicenter falls at a zone of abrupt change of crustal thickness. It seems that this great earthquake was the result of rapid faulting at the gradient zone of the crust-mantle boundary due to the action of N-S trending regional tectonic stress field. Because the focal depth is great, no earthquake faulting is observed on the surface. The deformation of the magistoseismic area is characterized mainly by physicogeologic phenomena such as collapse, landslides, and ground-fissures, accompanied by coseismic ruptures and folding of the active thin-skinned structures above the decollement.

Key words: Seismic rupture, Gradient zone of crust-mantle boundary, Seismogenic model

摘要： 在收集、分析前人资料及野外考察的基础上,重点研究了1902年阿图什8级地震形变特征与区域地震构造环境的关系,并结合震中区的地球物理探测成果,对该地震的发震模式进行了探讨。认为,阿图什大震的发生是塔里木与南天山两大块体相向对冲挤压的结果。较大的震源深度,使得震中区变形以较大规模和范围的崩塌、滑坡、地裂缝等重力地质现象为主,浅部薄皮活动构造亦发生了同震破裂及褶皱变形。

关键词: 地震形变特征, 壳幔界面陡变带, 发震模式