Late Miocene to present synchronous extension and contraction in the eastern Pamir: Insights from inversion of thermochronologic data across the southern Muztaghata dome

Late Cenozoic gneiss domes cover similar to 30% of the surface of the Pamir salient in the northwestern end of the India-Asia collision zone. The highest peaks of the Pamir are the east, where the similar to 250-km-long, similar to N-S-trending Kongur Shan extensional system controls the topography. We combined 115 new apatite (U-Th-Sm)/He and zircon (U-Th)/He single-grain dates from 18 samples and previous thermochronologic data with three-dimensional thermokinematic models to constrain the thermo-tectonic history of the southern portion of the Muztaghata dome, one of the largest gneiss domes in the eastern Pamir. The new cooling dates from the west-ern boundary of the southern Muztaghata dome generally increase with distance from the southern Kongur Shan fault and are re-lated to normal faulting along the fault at near-surface levels over the last 6.5 m.y. The new dates across the central-eastern portion of the dome outline the previously recorded U-shaped date pattern at a higher spatial resolu-tion. The modeling indicates that this pattern is most likely the result of uplift and erosion above a flat-ramp-flat thrust fault at depth over the last 7 m.y. Modeling does not resolve how topographic changes may have affected the observed distribution of cooling dates, but it indicates a faster thrust-slip rate associated with an increase in relief and a slower one as-sociated with steady-state topography. Our results suggest that the modern topography along the southern Muztaghata dome, simi-lar to the rest of the eastern Pamir salient, shaped by normal faulting at shallow depth, but its growth may still be governed by con-traction and crustal thickening at depth.