HR: 10:20h
AN: T22C-01    [Abstracts]
TI: Lithospheric structure of the Arabia-Eurasia collision zone in Eastern Anatolia from magnetotelluric exploration
AU: * Turkoglu, E
EM: eturk@phys.ualberta.ca
AF: University of Alberta, Department of Physics, University of Alberta, Edmonton, AB T6G 2J1, Canada
AU: Unsworth, M
EM: unsworth@phys.ualberta.ca
AF: University of Alberta, Department of Physics, University of Alberta, Edmonton, AB T6G 2J1, Canada
AU: Caglar, I
EM: caglari@itu.edu.tr
AF: Istanbul Technical University, Department of Geotechnical Engineering, Maslak, Istanbul, 34390, Turkey
AU: Tuncer, V
EM: vtuncer
AF: University of Alberta, Department of Physics, University of Alberta, Edmonton, AB T6G 2J1, Canada
AU: Avsar, U
EM: avsaru@itu.edu.tr
AF: Istanbul Technical University, Department of Geotechnical Engineering, Maslak, Istanbul, 34390, Turkey
AB: Continent-continent collisions are a fundamental tectonic process that has shaped the evolution of the Earth. A series of these collisions have occurred in the Alpine-Himalaya Mountain belt and produced high elevation plateau. Eastern Anatolia is the location of a relatively young (~13 Ma) continent-continent collision between the Arabian and Eurasian Plates. In contrast to the Tibetan Plateau, limited geophysical data is available to constrain the mode of deformation in Eastern Anatolia. The first long-period magnetotelluric (MT) data were collected in Eastern Anatolia in 2005 on profiles extending from the Arabian plate to the Black Sea. Geoelectric strike directions were mostly east-west, rather than parallel to the major strike-slip faults that define the boundaries of the tectonic blocks. Two dimensional MT inversions were used to obtain resistivity sections along the profiles. The Anatolian block that is being extruded to the west is characterized by a low resistivity (fluid rich?) lower crust underlain by normal upper mantle structure. In contrast, the Anatolian plateau is underlain by an upper mantle with an anomalously low electrical resistivity that could be accounted for by a few percent partial melt. The lower crust beneath the Anatolian plateau exhibits an abnormally low resistivity that also requires an elevated fluid content. This could have originated by under-thrusting of the Eastern Anatolian Accretionary Complex. The presence of fluids in both the crust and upper mantle may weaken the lithosphere sufficiently to permit lateral flow, and may also allow a decoupling of the upper and lower portions of the lithosphere. The lithospheric structure of the Anatolian Plateau is quite similar to that of the Tibetan Plateau, with widespread zones of elevated fluid content and weak rheology. This is despite the fact that the two areas have undergone quite different styles of tectonic evolution.
DE: 8108 Continental tectonics: compressional
DE: 8111 Continental tectonics: strike-slip and transform
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting