TY  - JOUR
A1  - Thiede, Rasmus Christoph
A1  - Sobel, Edward
A1  - Chen, Jie
A1  - Schoenbohm, Lindsay M.
A1  - Stockli, Daniel F.
A1  - Sudo, Masafumi
A1  - Strecker, Manfred
T1  - Late Cenozoic extension and crustal doming in the India-Eurasia collision zone new thermochronologic constraints from the NE Chinese Pamir
JF  - Tectonics
N2  - The northward motion of the Pamir indenter with respect to Eurasia has resulted in coeval thrusting, strike-slip faulting, and normal faulting. The eastern Pamir is currently deformed by east-west oriented extension, accompanied by uplift and exhumation of the Kongur Shan (7719m) and Muztagh Ata (7546m) gneiss domes. Both domes are an integral part of the footwall of the Kongur Shan extensional fault system (KES), a 250 km long, north-south oriented graben. Why active normal faulting within the Pamir is primarily localized along the KES and not distributed more widely throughout the orogen has remained unclear. In addition, relatively little is known about how deformation has evolved throughout the Cenozoic, despite refined estimates on present-day crustal deformation rates and microseismicity, which indicate where crustal deformation is presently being accommodated. To better constrain the spatiotemporal evolution of faulting along the KES, we present 39 new apatite fission track, zircon U-Th-Sm/He, and Ar-40/Ar-39 cooling ages from a series of footwall transects along the KES graben shoulder. Combining these data with present-day topographic relief, 1-D thermokinematic and exhumational modeling documents successive stages, rather than synchronous deformation and gneiss dome exhumation. While the exhumation of the Kongur Shan commenced during the late Miocene, extensional processes in the Muztagh Ata massif began earlier and have slowed down since the late Miocene. We present a new model of synorogenic extension suggesting that thermal and density effects associated with a lithospheric tear fault along the eastern margin of the subducting Alai slab localize extensional upper plate deformation along the KES and decouple crustal motion between the central/western Pamir and eastern Pamir/Tarim basin.
KW  - Pamir
KW  - gneiss domes
KW  - collision
KW  - extension
KW  - thermochronology
KW  - exhumation
Y1  - 2013
U6  - https://doi.org/10.1002/tect.20050
SN  - 0278-7407
VL  - 32
IS  - 3
SP  - 763
EP  - 779
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Sobel, Edward
A1  - Chen, Jie
A1  - Schoenbohm, Lindsay M.
A1  - Thiede, Rasmus Christoph
A1  - Stockli, Daniel F.
A1  - Sudo, Masafumi
A1  - Strecker, Manfred
T1  - Oceanic-style subduction controls late Cenozoic deformation of the Northern Pamir orogen
JF  - Earth & planetary science letters
N2  - The northern part of the Pamir orogen is the preeminent example of an active intracontinental subduction zone in the early stages of continent-continent collision. Such zones are the least understood type of plate boundaries because modern examples are few and of limited access, and ancient analogs have been extensively overprinted by subsequent tectonic and erosion processes. In the Pamir, it has been assumed that most of the plate convergence was accommodated by overthrusting along the plate-bounding Main Pamir Thrust (MPT), which forms the principal northern mountain and deformation front of the Pamir. However, the synopsis of our new and previously published thermochronologic data from this region shows that the hanging wall of the MPT experienced relatively minor amounts of late Cenozoic exhumation. The Pamir orogen as a whole is an integral part of the overriding plate in a subduction system, while the remnant basin to the north constitutes the downgoing plate, with the bulk of the convergence accommodated by underthrusting. Herein, we demonstrate that the observed deformation of the upper and lower plates within the Pamir-Alai convergence zone resembles highly arcuate oceanic subduction systems characterized by slab rollback, subduction erosion, subduction accretion, and marginal slab-tear faults. We suggest that the curvature of the North Pamir is genetically linked to the short width and rollback of the south-dipping Alai slab; northward motion (indentation) of the Pamir is accommodated by crustal processes related to this rollback. The onset of south-dipping subduction is tentatively linked to intense Pamir contraction following break-off of the north-dipping Indian slab beneath the Karakoram.
KW  - subduction accretion
KW  - subduction erosion
KW  - exhumation
KW  - thermochronology
KW  - intracontinental deformation
KW  - Pamir
Y1  - 2013
U6  - https://doi.org/10.1016/j.epsl.2012.12.009
SN  - 0012-821X
VL  - 363
IS  - 1
SP  - 204
EP  - 218
PB  - Elsevier
CY  - Amsterdam
ER  -