HR: 1340h
AN: GP33B-1253    [Abstracts]
TI: Magnetotelluric Evidence of Thick-skinned Thrusting in the Southern Tien Shan, Kyrgyzstan and China?
AU: * Park, S K
EM: magneto@ucrmt.ucr.edu
AF: Department of Earth Sciences, University of California, Riverside, CA 92521, United States
AU: Rybin, A
EM: rybin@gdirc.ru
AF: Scientific Station of the Russian Academy of Sciences, 720049, Bishkek-49, Bishkek, 720049, Kyrgyzstan
AU: Batalev, V
EM: batalev@gdirc.ru
AF: Scientific Station of the Russian Academy of Sciences, 720049, Bishkek-49, Bishkek, 720049, Kyrgyzstan
AU: Jianing, S
EM: sunjn116@163.com
AF: Xinjiang Seismological Bureau, No. 42 South Beijing Road Urumqi, Xinjiang Province, Urumqi, 830011, China
AB: A profile of broadband MT stations was acquired in 2005 in association with a planned 500 km long seismic reflection line shot in 2007. This profile extended from south of Kashgar, China, to just south of Bishkek, Kyrgyzstan and consisted of 73 stations spanning the northern part of the Tarim Basin and most of the Tien Shan mountains in Kyrgyzstan. Here, we report on a model derived from the southernmost 40 broadband and long period stations that coincides with a seismic line shot by Chinese geophysicists. Broadband data confirm earlier results that the conductive sediments in the Tarim Basin extend to almost 10 km depth. Most intriguing is an antiformal feature that spans depths from 10 to 40 km whose crest lies beneath the Kashgar anticline. This antiformal feature lies beneath detachment faults at depths of 6 to 8 km that have been identified from surface geology and seismic reflection data by other authors. It also lies beneath the deepest structures visible in the 2007 reflection line. While it is possible that the structure is a basement relict from an earlier tectonic phase, the spatial association with late Cenozoic deformation supports an interpretation that it is young. If so, then the lithosphere beneath the shallower detachment faults is also deforming.
DE: 0925 Magnetic and electrical methods (5109)
DE: 8110 Continental tectonics: general (0905)
DE: 8124 Earth's interior: composition and state (1212, 7207, 7208, 8105)
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Fall Meeting