Cenozoic uplift, exhumation and deformation in the north Kuqa Depression, China as constrained by (U–Th)/He thermochronometry

Abstract

Placing spatial and temporal constraints on deformation, uplift and exhumation using thermochronology methods can shed light on Cenozoic orogenic evolution in the Kuqa foreland. New apatite (U–Th)/He and previ- ously published apatite fission track thermochronology are combined with vitrinite reflectance data and model- ing to compile a low temperature, multi-stage thermal history of tectonic uplift/thrust and exhumation. A rapid uplift and exhumation event originated in South Tianshan during the Eocene (~46 Ma), with systematic younging of mean apatite (U–Th)/He ages from north to south (from the margin towards the interior). Uplift and exhumation south edge of the Biyoulebaoguzi anticline in the northern monocline belt at ~36 Ma with more than 3400 m of stratum denuded. Subsequently, deformation and uplift south edge of the Biyoulebaoguzi anticline in the northern monocline belt at ~36 Ma with more than 3400 m of stratum denuded. Subsequently, deformation and uplift extended to the northern edge of Kelasu–Yiqikelike at ~10 Ma and then at ~6 Ma, the Kanyaken anticline formed and uplifted resulting in 3000–3700 m of overburden erosion. The data support se- quential southward propagating deformation and uplift (inferred exhumation) in the north Kuqa Depression during the Cenozoic, probably as a result of the collision of India with Asia far to the south of the Tianshan.