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Teleseismic primary (P) to secondary (S) converted waves recorded on the INDEPTH III seismic array have been used to detect lithospheric-scale deformation structures of the central Tibetan Plateau from the central Lhasa terrane to the central Qiangtang terrane. A south-dipping crustal converter is seen from the upper crust near the 500-km-long metamorphic core complex exposures in the Qiangtang terrane to the lower crust near the Bangong-Nujiang suture. At deeper depths, a southeast-dipping mantle converter is seen extending from ~50 km north of the Bangong-Nujiang suture at the depth of the Moho, to a depth of ~180 km, ~100 km south of the Bangong-Nujiang suture. We found the observations to be most consistent with a model of lithospheric deformation involving (1) southward subduction of the Tibetan lithospheric mantle along the Bangong-Nujiang suture and (2) thickening of the central Tibetan crust through a thick-skinned, crustal accretionary thrust-wedge structure in response to the India's collision with Asia. Keywords: receiver function, lithospheric structure, continental collision, Tibetan Plateau.

A broadband seismic deployment in 1998-1999 in southwestern Tarim provided data for imaging the crust and upper mantle across the contact between the Tarim block and the Tibetan Plateau. A profile composed of migrated teleseismic receiver functions clearly shows lateral structural changes. The crust under the Tarim basin is relatively simple. The Moho discontinuity is mapped at a depth of 42 km near the northern end of the array and dips gently toward the south to ~50 km under the Kunlun foreland. The Tarim basin appears to be rigid, with little shortening. Farther to the south, the imaging reveals a complex of reflectors in the lower crust and the upper mantle. There are both north- and south-dipping upper mantle structures under the Kunlun foreland and Kunlun Shan region. We found the observations to be more consistent with a model of lithospheric collision in which the crust and the upper mantle on both sides interpenetrate and deform. Keywords: receiver function image, lithospheric collision, Tarim, Tibet.