Slip partitioning in the northeast Pamir-Tian Shan convergence zone

Based on a detailed analysis of satellite imagery combined with field geologic and geomorphic observations, we have mapped late Cenozoic folds and faults in the northeastern Pamir-Tian Shan convergence zone. It is a unique example to understand intracontinental ongoing mountain building within India-Eurasia collision system. in the front of northeastern Pamir, our investigations reveal that the NW-WNW-trending folds display a right-stepping en echelon pattern and NW-WNW-striking faults are mainly characterized by south-dipping thrusts with an extensive dextral strike-slip component. Drainage systems across the active faults show a systematic right-lateral offset. In contrast, structural style of the ENE trending fold-and-thrust belts are predominated by south-north directed shortening southwest of the Tian Shan. Our results also infer that oblique thrusting accommodates as long-term dextral slip rate of ca. 4.0 mm/yr during the late Cenozoic time north of the Pamir topographic front. Tectono-stratigraphic evidence suggests that the tectonic deformation was initiated at ca. 3-5 Ma in the study area. We suggest that intracontinental mountain building in the Pamir-Tian Shan convergence zone should be attributed to the crustal shortening caused by folding and thrusting as well as block rotation related to strike-slip faulting within the India-Eurasia collision system. (C) 2009 Elsevier B.V. All rights reserved.