Thermochronological constraints on the Late Cenozoic evolution of the northeastern Pamir

Situated at the northwestern end of the India–Asia collision zone, the northeastern Pamir is an important area to explore intracontinental tectonic processes and geodynamic models. In this study, thermochronology is applied to constrain the Late Cenozoic exhumation history of the northeastern Pamir. A new thermochronological data set, combined with previous thermochronological data, suggests that (1) the Late Cenozoic exhumation of the northeastern Pamir began at ~22–18 Ma; (2) the strong crustal contraction in the hinterland of the northeastern Pamir occurred during ~13–10 Ma and ~8–6 Ma; and (3) the east-west extension along the Kongur Shan dome initiated at ~5–3 Ma, and it has resulted in the exhumation of the core of the dome with an average rate of ~2–4 mm/a. I propose that (1) the Early Miocene exhumation of the northeastern Pamir is related to the initiation of the Main Pamir thrust; (2) the first and second stages of the strong crustal contraction are respectively correlated with the northward propagation of the crustal channel flow in the northeastern Pamir and the initial collision between the northeastern Pamir and the Tian Shan; and (3) the east-west extension is driven by the extrusion of the ductile channel flow.