Cenozoic right-slip faulting along the eastern margin of the Pamir salient, northwestern China

Research Article| January 01, 2010 Cenozoic right-slip faulting along the eastern margin of the Pamir salient, northwestern China Eric Cowgill Eric Cowgill † Department of Geology, University of California, Davis, California 95616, USA †E-mail: ecowgill@ucdavis.edu Search for other works by this author on: GSW Google Scholar Author and Article Information Eric Cowgill † Department of Geology, University of California, Davis, California 95616, USA †E-mail: ecowgill@ucdavis.edu Publisher: Geological Society of America Received: 16 Aug 2008 Revision Received: 27 Jan 2009 Accepted: 09 Feb 2009 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2010 Geological Society of America GSA Bulletin (2010) 122 (1-2): 145–161. https://doi.org/10.1130/B26520.1 Article history Received: 16 Aug 2008 Revision Received: 27 Jan 2009 Accepted: 09 Feb 2009 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Eric Cowgill; Cenozoic right-slip faulting along the eastern margin of the Pamir salient, northwestern China. GSA Bulletin 2010;; 122 (1-2): 145–161. doi: https://doi.org/10.1130/B26520.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The Pamir salient defines the western end of the Himalayan-Tibetan orogen and has overthrust the Tarim-Tajik basin to the north by ∼300 km along a late Cenozoic, south-dipping intracontinental subduction zone. Field mapping, structural measurements, and analysis of mesoscale structures along a 32-km-long reach of the Yarkand River document the tectonic evolution of the east flank of this salient, between the North Pamir to the west and the Western Kunlun Shan to the east. The study area is cut by a set of four, north-northwest–striking, steeply dipping brittle faults. Microstructures and asymmetric outcrop- to map-scale folds indicate right slip along these faults. Between these structures, fault-bounded panels of Phanerozoic strata are deformed by en echelon folds with axes that trend more westerly than the adjacent faults, consistent with dextral transpression. The fault system described here extends for ∼350 km along the eastern flank of the Pamir salient. Transpressional right slip along this set of faults, here called the Kashgar-Yecheng transfer system, appears to have accommodated late Cenozoic separation of the North Pamir from the Western Kunlun Shan during south-directed intracontinental subduction beneath the leading edge of the Pamir salient. Correlation of major faults suggests total slip along the Kashgar-Yecheng transfer system is likely on the order of ∼280 km. This offset estimate implies long-term slip rates of 7–15 mm/a along the Kashgar-Yecheng transfer system when combined with previous sedimentologic, stratigraphic, and thermochronologic data that indicate deformation along the east flank of the Pamir started between the late Eocene and early Miocene. These results imply that the first-order structures on the western and eastern flanks of the Pamir are asymmetric: previous work has shown that deformation in the west was accommodated by anticlockwise vertical axis rotation of the Pamir over the eastern margin of the Tajik basin. This rotation is generally interpreted to reflect northwest-directed radial thrusting, in contrast to the transpressional right-slip transfer faulting on the east side reported here. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.