Seismic image of the Tarim basin and its collision with Tibet
- 1Institute of Earth Sciences, Academia Sinica, Nankang, Taipei 115, ROC
- 2Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, PRC
- 3Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan 701, ROC
- 4Institute of Geophysics, National Central University, Chung-Li, Taiwan 320, ROC, and Seismology Center, Central Weather Bureau, Taipei 100, ROC
- 5Department of Geological Sciences, State University of New York, Binghamton, New York 13902, USA
Abstract
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.
Footnotes
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- Accepted March 15, 2001.
- Received October 5, 2000.
- Revision received March 2, 2001.
- Geological Society of America
