Deep Crustal Contact Between the Pamir and Tarim Basin Deduced From Receiver Functions

Abstract The deep crustal deformation in the east Pamir in response to the Cenozoic collision with the Tien Shan and the Tarim Basin is so far poorly constrained. We present new insights into the crustal structure of the east Pamir and its surrounding regions using P receiver functions from 40 temporary and permanent seismic stations. The crustal thickness reaches a maximum of 88 km beneath the central and southern east Pamir and decreases sharply to 50–60 km along the southern Tien Shan and to 41–50 km below the Tarim Basin. The most prominent crustal structures involve a double Moho, suggesting eastward underthrusting of the Pamir lower crust beneath southern east Pamir, and two Moho offsets, supporting delamination of Asian lower crust below the central east Pamir and pure shear shortening along the northeastern margin between the Pamir and Tarim Basin.