Partitioning of India-Eurasia convergence in the Pamir-Hindu Kush from GPS measurements

Convergence of 29 ± 1 mm/yr between the NW corner of the Indian plate and Asia is accommodated by a combination of thrust and strike-slip faulting on prominent faults and apparent distributed deformation within the Hindu Kush, Pamir, South Tien Shan and Kohistan Ranges. An upper bound to the slip rate of known faults is obtained by ignoring distributed strain and rotation: convergence occurs on thrust faults north of the Peshawar Basin (13 ± 1 mm/yr) and in the Alai-South Tien Shan (12 ± 2 mm/yr), and shear on the northeast-trending northern Chaman-Gardiz-Konar system (18 ± 1mm/yr) and the Darvaz-Karakul fault zone (11 ± 2 mm/yr). Slip rates on the Herat and Talas-Ferghana faults are small (<2 mm/yr). Shortening not attributable to known active faults occurs within the Hindu Kush and central Pamir (16 ± 2 mm/yr) with concomitant east-west extension in the latter of 9 ± 2 mm/yr. This diversity of strain styles confirms the importance of mechanical heterogeneity to continental tectonics and shows that the Pamir, although less than half the size, behaves more like Tibet than like a linear belt of localized deformation.