HR: 0800h
AN: T41B-1294    [Abstracts]
TI: Strike-slip faulting, rotation, and along-strike extension in the Kopeh Dagh mountains, NE Iran
AU: * Hollingsworth, J
EM: hollingsworth@esc.cam.ac.uk
AF: University of Cambridge, Bullard Laboratories, Department of Earth Sciences, Madingley Road, Cambridge., CB30EZ United Kingdom
AU: Jackson, J
EM: jackson@esc.cam.ac.uk
AF: University of Cambridge, Bullard Laboratories, Department of Earth Sciences, Madingley Road, Cambridge., CB30EZ United Kingdom
AU: Walker, R
EM: richard.walker@earth.ox.ac.uk
AF: University of Oxford, Department of Earth Sciences, Parks Road, Oxford., OX13PR United Kingdom
AU: Gheitanchi, M R
EM: mrghchee@chamran.ut.ac.ir
AF: Tehran University, Institute of Geophysics, PO Box 13145--1137, Tehran., 13145 Iran (Islamic Republic of)
AU: Bolourchi, M J
EM: amir_blur@yahoo.com
AF: Geological Survey of Iran, Azadi Square, Meraj Avenue, PO Box 13185--1494, Tehran., 13185 Iran (Islamic Republic of)
AB: The Kopeh Dagh is a linear mountain range separating the shortening in Iran from the stable, flat Turkmenistan shield. In its central part is an array of active right-lateral strike-slip faults that obliquely cut the range and produce offsets of several kilometers in the geomorphology and geological structure. They are responsible for major destructive earthquakes in the 19th and 20th centuries and represent an important seismic hazard for this now-populous region of NE Iran. These strike-slip faults all end in thrusts, revealed by the uplift and incision of late Quaternary river terraces, and do not continue beyond the Atrek river valley, which forms the southern margin of the Kopeh Dagh. The cumulative offset on these strike-slip faults, and their associated rotation about vertical axes, can account for ~ 60~km of N-S shortening. This value is similar to the Late Quaternary N-S right-lateral shear between central Iran and Afghanistan, which must be accommodated in NE Iran. The strike-slip faults also require ~ 30~km of along-strike extension of the Kopeh Dagh, which is taken up by the westward component of motion between the South Caspian Basin and both Eurasia and central Iran. It is probable that these motions occurred over the last ~ 10~Ma.
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
DE: 8040 Remote sensing
DE: 8107 Continental neotectonics (8002)
DE: 8111 Continental tectonics: strike-slip and transform
DE: 8175 Tectonics and landscape evolution
SC: Tectonophysics [T]
MN: Fall Meeting 2005