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Crustal structure across the Altyn Tagh Range at the northern margin of the Tibetan Plateau and tectonic implications

Earth and Planetary Science Letters

By:
, , , , , and
DOI: 10.1016/j.epsl.2005.11.003

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Abstract

We present new seismic refraction/wide-angle-reflection data across the Altyn Tagh Range and its adjacent basins. We find that the crustal velocity structure, and by inference, the composition of the crust changes abruptly beneath the Cherchen fault, i.e., ???100 km north of the northern margin of the Tibetan plateau. North of the Cherchen fault, beneath the Tarim basin, a platform-type crust is evident. In contrast, south the Cherchen fault the crust is characterized by a missing high-velocity lower-crustal layer. Our seismic model indicates that the high topography (???3 km) of the Altyn Tagh Range is supported by a wedge-shaped region with a seismic velocity of 7.6-7.8 km/s that we interpret as a zone of crust-mantle mix. We infer that the Altyn Tagh Range formed by crustal-scale strike-slip motion along the North Altyn Tagh fault and northeast-southwest contraction over the range. The contraction is accommodated by (1) crustal thickening via upper-crustal thrusting and lower-crustal flow (i.e., creep), and (2) slip-parallel (SW-directed) underthrusting of only the lower crust and mantle of the eastern Tarim basin beneath the Altyn Tagh Range. ?? 2005 Elsevier B.V. All rights reserved.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Crustal structure across the Altyn Tagh Range at the northern margin of the Tibetan Plateau and tectonic implications
Series title:
Earth and Planetary Science Letters
DOI:
10.1016/j.epsl.2005.11.003
Volume
241
Issue:
3-4
Year Published:
2006
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Earth and Planetary Science Letters
First page:
804
Last page:
814
Number of Pages:
11