Teleseismic imaging of subducting lithosphere and Moho offsets beneath western Tibet

Teleseismic images suggest that the Tarim plate plunges similar to 45degreesS, down to similar to 300 kin depth, beneath NW Tibet. The 410 km discontinuity shallows by similar to10 km under the plateau, implying similar to 100degreesC cooler upper mantle. The deepest Moho on record ( similar to 90 km) lies under W Qiangtang. It rises abruptly by similar to 20 and similar to 10 km beneath the Altyn Tagh Fault and Bangong Suture, respectively. V-p/V-s ratios are normal, except in the Yecheng flexural basin and deep under the south Karakax volcanics (similar to 1.92). W Kunlun's Neogene tectonics are simply accounted for by oblique subduction of lithospheric mantle beneath an upward-extruding thrust wedge of the Tarim crust. (C) 2004 Elsevier B.V. All rights reserved.