TY  - JOUR
A1  - Haghipour, Negar
A1  - Burg, Jean-Pierre
A1  - Kober, Florian
A1  - Zeilinger, Gerold
A1  - Ivy-Ochs, Susan
A1  - Kubik, Peter W.
A1  - Faridi, Mohammad
T1  - Rate of crustal shortening and non-Coulomb behaviour of an active accretionary wedge - the folded fluvial terraces in Makran (SE, Iran)
JF  - Earth & planetary science letters
N2  - We surveyed fluvial terraces to decipher the Quaternary increment of crustal shortening and shortening rate in the on-shore Makran Accretionary Wedge. We focused on three major catchment basins and associated fold systems. Terrace profiles reconstructed from differential GPS measurements combined with DEM revealed two regional dominant wavelengths, about 5 km in the northern part of the study area and about 15 km to the south. These two wavelengths suggest the existence of two active decollement layers at two rooting depths. The average shortening rate due to folding is estimated at 0.8-1.2 mm/a over the last 130 ka. This accounts for 10-15% of the shortening rate (similar to 8 mm/a) given by kinematic GPS measurements between Chabahar and Bazman and 3% of the convergence between Arabia and Eurasia, across the Makran subduction zone. Despite active deformation and a relatively high shortening rate, the geophysical record shows nearly absent seismic activity in Makran. We propose that strain accumulated in folds over intermediate decollement levels within a thick, incompletely lithified sedimentary cover explains the essentially aseismic, recent tectonics in this region. The importance of folds points to imperfect Coulomb behaviour of the wedge. (C) 2012 Elsevier B.V. All rights reserved.
KW  - fluvial terraces
KW  - Be-10 dating
KW  - accretionary wedge
KW  - shortening rate
Y1  - 2012
U6  - https://doi.org/10.1016/j.epsl.2012.09.001
SN  - 0012-821X
VL  - 355
SP  - 187
EP  - 198
PB  - Elsevier
CY  - Amsterdam
ER  -