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穿越NE向阿尔金断裂带,首次进行天然地震探测获取了大量远震与近震资料。对数据进行了层析分析、接收函数和震源定位的研究。提供了阿尔金断裂深部构造的新资料。地震层析资料表明,软流圈的大致深度在100 km、地壳各部位的速度特征有较大差异,推断南缘断裂产状较陡。沿此断裂出现的幔源物质,在层析图象上呈低速体。北缘的断裂带属高速带,但深部则为相对的低速体。接收函数的结果显示北缘断裂带在浅部产状缓。北缘断裂带在深部应与南缘断裂相会,可能正是塔里木地块的地壳向柴达木地块下部(向南东)插入的表现。可以认为,塔里木地块在岩石圈深部进入了青藏高原的下部,而阿尔金断裂带控制着青藏高原地块向北挤出。
A large number of teleseismic and near-earthquakes data have been obtained through the first NEO seismic exploration to the Altyn Tagh fault. The data were analyzed by tomography, receiver function and source localization. Provides new information on the deep structure of the Altyn Tagh fault. Seismic tomographic data show that the approximate depth of the asthenosphere is about 100 km, and the velocity characteristics of various parts of the crust are quite different. It is inferred that the occurrence of the southern margin is steeper. The mantle-derived material that appears along the fault appears as a low velocity body on the tomographic image. The northern margin of the fault belt is a high-speed zone, but the deep is relatively low-speed body. The results of the receiver function show that the northern margin of fault ruptures in the shallow part. The north margin fault zone should meet in the deep with the southern margin fault, which may be the result of the insertion of the crust of the Tarim block into the lower part of the Qaidam block (to the south and east). It can be considered that the Tarim block has entered the lower part of the Qinghai-Tibet Plateau in the deep lithosphere while the Altyn Tagh fault controlled the massif of the Qinghai-Tibet Plateau to the north.