Late Cenozoic volcanism and rates of active faulting in eastern Iran

Walker, R. T. and Gans, P. and Allen, M. B. and Jackson, J. A. and Khatib, M. and Marsh, N. and Zarrinkoub, M. (2009) Late Cenozoic volcanism and rates of active faulting in eastern Iran. Geophysical journal international, 177 (2). pp. 783-805. ISSN Online ISSN 1365-246X Print ISSN 0956-540X DOI 10.1111/j.1365-246X.2008.04024.x

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Abstract

We present new 40Ar/39Ar ages of samples of volcanic rock exposed along the remote margins of the Dasht-e Lut desert in eastern Iran. Close spatial relationships between the volcanic rocks and the trace of active strike-slip faults allow us to determine the slip rates of two major faults, averaged since eruption of the volcanics. Our study shows that the Nayband fault at the western margin of the Dasht-e Lut has a slip rate of 223C1.4 o?= 0.5 mm yr22121 averaged over 2.25 Ma. The East Neh fault, one of several active strike-slip faults within the Sistan Suture Zone at the eastern margin of the Dasht-e Lut, has a minimum slip rate of 223C1.2 mm yr22121 averaged over 223C1.7 Ma. The rates of slip on major active faults in eastern Iran are largely unknown, and the slip rates our data provide, though limited, are a significant increase on what is known of the faulting within this remote and relatively inaccessible desert region. We also present analyses of the major and trace element concentrations within the volcanic rocks. The chemistry of the volcanic rocks is typical of intracontinental melts with an overall signature similar to that of ocean island basalts. Inversion of rare earth element distributions suggests some melting has occurred at depths of 223C80 km, indicating the presence of a relatively thin lithosphere beneath eastern Iran, in agreement with recently published maps of lithospheric thickness derived from shear wave velocities.

Item Type:	Article
Additional Information:	© 2009 The Authors Journal compilation © 2009 RAS
Uncontrolled Keywords:	08AREP IA57
Subjects:	02 - Geodynamics, Geophysics and Tectonics
Divisions:	02 - Geodynamics, Geophysics and Tectonics
Journal or Publication Title:	Geophysical journal international
Volume:	177
Page Range:	pp. 783-805
Identification Number:	10.1111/j.1365-246X.2008.04024.x
Depositing User:	Sarah Humbert
Date Deposited:	07 Jul 2015 15:10
Last Modified:	07 Jul 2015 15:16
URI:	http://eprints.esc.cam.ac.uk/id/eprint/3398

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