south central Tibet

Himalayan domes in south central Tibet, consists of a multiphase granite core surrounded by a deformed metasedimentary carapace. The granitic core records general non‐coaxial shear with a top‐to‐the‐south sense shear component. The contact between the core and the carapace is a shear zone, characterized by general non‐coaxial shear with a top‐to‐the‐north shear sense, interpreted to be the northern continua-tion of the South Tibetan detachment system (STDS). The shear zone contains lenses of leucogranite dated at 35.4 Ma. This is interpreted to reflect Eocene crustal thickening, coeval with the earliest shortening event recorded in the carapace. The main phase of the Changgo granite crystallized at 23.5 Ma, while unde-formed aplite dikes, the youngest phase observed in the granite, were intruded at 22.1 Ma. Aplite dikes crosscut themain deformation fabric within the Changgo granite; therefore, that deformation and associated south directed shearingmust have ended between 23.5Ma and 22.1Ma. The dikes are strained within the STDS, indicating that final displacement along the STDS must post‐date 22 Ma, yet be older than 18.4 Ma, the cooling age of muscovite in the shear zone. It is proposed that the exhumation of the Changgo culmination is related to tectonically driven erosion in response to crustal thick-ening and rebuilding of the orogenic critical taper wedge. Subsequently, deformation in the wedge migrat-ed toward the foreland, expanding the orogenic wedge laterally and moving the locus of displacement from the Main Central thrust structurally downward to th