Abstract
Based on new structural and petrological investigations, we present two crustal-scale cross-sections of the Kyrgyz South Tien Shan, and correlations of main faults and units between Kyrgyzstan and China. The overall structure corresponds to a doubly-vergent mountain belt. The Kyrgyz and Chinese areas exhibit identical structural and metamorphic histories. To the west, the Atbashi Range comprises high-pressure oceanic and continental units stacked by north-verging thrusts above a low metamorphic accretionary prism. High-pressure (HP) gneisses are bound to their south by a south-dipping detachment exhibiting mantle relicts. The high-pressure oceanic and continental units underwent similar pressure–temperature (P–T) paths with peak conditions of around 500 °C–20 kbar, followed by rapid exhumation. The overall south-dipping structure and kinematics indicate a south-dipping subduction of the Central Tien Shan Ocean at 320–310 Ma, ending with the docking of the Tarim block to the Kazakh continent. To the east, the Pobeda Massif shows a narrow push-up structure. A major north-vergent thrust exhumes deep-crustal-level granulites, constituting the highest summits, which were thrust towards the north onto low-grade Devonian–Carboniferous schists. The southern part of South Tien Shan is made up of a south-verging thrust stack that formed later during ongoing convergence, reactivated throughout post-30 Ma phases.