HR: 11:40h
AN: T31E-12
TI: Conductivity Structure of the Bangong Suture Zone from INDEPTH Magnetotelluric Data
AU: * Solon, K D
EM: [email protected]
AF: Department of Earth Sciences Syracuse University, 204 HGL, Syracuse, NY 13244 United States
AU: Jones, A G
AF: Geological Survey of Canada, 615 Booth St. Room 218 , Ottawa, ONT K1A 0E9 Canada
AU: Nelson, K D
AF: Department of Earth Sciences Syracuse University, 204 HGL, Syracuse, NY 13244 United States
AU: Unsworth, M J
AF: Geophysics Program University of Washington, Box 351650, Seattle, WA 89195 United States
AU: Wei, W
AF: China University of Geosciences, Dept. of Applied Geophysics 29 Xueyuan Road , Beijing, 100083 China
AU: Tan, H
AF: China University of Geosciences, Dept. of Applied Geophysics 29 Xueyuan Road , Beijing, 100083 China
AB: As part of the collaborative and ongoing efforts of project INDEPTH, both broadband and long period magnetotelluric (MT) data were collected from July to August 1998 along a 400 km north-south profile ("500-line") in central Tibet. The profile crosses the Bangong Suture, which is the principal terrane boundary within the central Tibetan Plateau and coincides with marked south-to-north changes in the seismological properties of the plateau lithosphere. Tensor distortion analysis were applied to the MT data from the sites around the suture in order to determine dimentionality and derive a regional geoelectric strike direction and regional MT response functions. These analyses suggest that the regional electrical structure is two-dimensional to periods of 5000 seconds, with a strike direction of N53E. This strike direction was unexpected, as the surficial geological strike is 90 degrees in this region. Preliminary 2D inversions of the MT data show the following first-order features. (1) The regional midcrustal conductor sensed previously in the southern Tibetan Plateau continues into the central plateau, with its top at depths of 15-20 km beneath the suture zone. (2) The Bangong Suture coincides with a 40 km wide, south-dipping, conductive zone which extends upward from the regional midcrustal conductor to the near surface.(3)
DE: 8110 Continental tectonics--general (0905)
SC: T
MN: 1999 AGU Fall Meeting