Sichuan Basin and beyond: Eastward foreland growth of the Tibetan Plateau from an integration of Late Cretaceous-Cenozoic fission track and (U-Th)/He ages of the eastern Tibetan Plateau, Qinling, and Daba Shan

Combining 121 new fission track and (U-Th)/He ages with published thermochronologic data, we investigate the Late Cretaceous-Cenozoic exhumation/cooling history of the eastern Tibetan Plateau, Qinling, Daba Shan, and Sichuan Basin of east central China. The Qinling orogen shows terminal southwestward foreland growth in the northern Daba Shan thrust belt at 100-90Ma and in the southern Daba Shan fold belt at 85-70Ma. The eastern margin of Tibetan Plateau experienced major exhumation phases at 70-40Ma (exhumation rate 0.05-0.08mm/yr), 25-15Ma (1mm/yr in the Pengguan Massif; similar to 0.2mm/yr in the imbricated western Sichuan Basin), and since similar to 11-10Ma along the Longmen Shan (similar to 0.80mm/yr) and the interior of the eastern Tibetan Plateau (Dadu River gorge, Min Shan; similar to 0.50mm/yr). The Sichuan Basin records two basin-wide denudation phases, likely a result of the reorganization of the upper Yangtze River drainage system. The first phase commenced at similar to 45Ma and probably ended before the Miocene; >1km of rocks were eroded from the central and eastern Sichuan Basin. The second phase commenced at similar to 12Ma and denudated the central Sichuan Basin, Longmen Shan, and southern Daba Shan; more than 2km of rocks were eroded after the lower Yangtze River had cut through the Three Gorges and captured the Sichuan Basin drainage. In contrast to the East Qinling, which was weakly effected by late Cenozoic exhumation, the West Qinling and Daba Shan have experienced rapid exhumation/cooling since similar to 15-13Ma, a result of growth of the Tibetan Plateau beyond the Sichuan Basin.