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使用TIBET-31N无源地震台阵以及以前临时地震台阵记录到的远震体波数据进行了有限频层析成像反演,对青藏高原南部及中部的三维速度结构成像。在喜马拉雅和拉萨地块下方存在向北倾角40°的高速体。我们把这些高速异常区域解释为俯冲的印度大陆岩石层(ICL)。印度大陆岩石层似乎在青藏高原中部比东部向北延伸更多——沿85°E在31°N到达350km深处,而沿91°E则是在30°N到达350km深度。P波和S波低速异常区在当惹雍错裂谷、亚东—谷露裂谷和错那裂谷下方从下地壳延伸至≥180km深度,这表明青藏高原南部的裂谷可能包含了整个岩石层的变形。当惹雍错裂谷下方的异常区向下延伸到约180km,而亚东—谷露裂谷西部和错那裂谷东部的异常延伸到了超过300km的深度。亚东—谷露裂谷西部的低速区上地幔延伸至最北,并且似乎与青藏高原中部下方广阔的上地幔低速区相连。于是,北向俯冲的印度板块沿着南北走向的裂缝撕裂。这些裂缝允许或者导致的软流层上涌同青藏高原北部上地幔相类似。
Finite-frequency tomographic inversion of TIBET-31N passive seismic array and teleseismic body-wave data previously recorded by the temporary seismic array were performed to image the 3D velocity structure in the southern and central Tibetan Plateau. Below the Himalayas and Lhasa massifs there is a high-speed body with a 40 ° dip to the north. We interpret these high-velocity anomalies as subducted Indian continental lithologies (ICLs). The Indian continental lithosphere appears to extend north-east of the central Tibetan Plateau more than east to the east - reaching a depth of 350 km at 31 ° N along 85 ° E and a depth of 350 km at 91 ° E at 30 ° N. The P-wave and S-wave low-rate anomalous zones extend from the lower crust to the depth of ≥180km below the Jyrong fault, Yadong-Gulu rift and faulty rift, suggesting that the southern rift in the Tibetan Plateau may contain the entire Deformation of the rock layer. When the anomaly zone below the Jurche fault extends downwards to about 180 km, the anomaly in the west of the Yadong-Gulluk Valley and the eastern part of the Wakana rift extends beyond 300 km. The upper mantle extends to the far north in the low-velocity region of the Yadong-Gulu rift, and appears to be connected to the vast low-velocity upper mantle beneath the central Tibetan Plateau. As a result, the subducted Indian plate tearing along the north-south crack. These cracks allow or cause the upwelling of the asthenosphere to be similar to the upper mantle in the northern part of the Tibetan Plateau.