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Titel |
Mapping crustal structure beneath southern Tibet: new seismic evidence for continental crustal underthrusting |
VerfasserIn |
Qiang Xu, Junmeng Zhao, Xiaohui Yuan, Hongbin Liu, Shunping Pei |
Konferenz |
EGU General Assembly 2013
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 15 (2013) |
Datensatznummer |
250076313
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Zusammenfassung |
Receiver function image along a temporary seismic array (ANTILOPE-2) reveals detailed information of the underthrusting of the Indian crust beneath southern Tibet. The Moho dips northward from ~50 km to 80 km depth beneath Himalaya terrane and reaches locally a depth of 90 km beneath the Indus-Yalung suture (IYS). It remains at ~80 km in Lhasa terrane and shallows to ~70 km in Qiangtang terrane. A lower crustal interface at ~60 km depth beneath Lhasa terrane can be clearly followed southward through the Main-Himalaya-Thrust (MHT) and connects the Main-Boundary-Thrust (MBT) at the surface, which represents the border of the Indian crust that is underthrusting the Tibetan crust until south of Bangong-Nujiang Suture (BNS) at ~32°N. We also observed a wide-spread mid-crustal low velocity zone with increasing depth from ~15 km in Lhasa terrane southward to ~35 km beneath high Himalaya that is terminated at the MHT. The low-velocity zone is thought to be formed by partial melt and/or aqueous fluids. |
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