Cretaceous and Cenozoic cooling history across the ultrahigh pressure Tongbai-Dabie belt, central China, from apatite fission-track thermochronology

Abstract

The crystalline terrane of the Tongbai-Dabie region, central China, comprising the Earth's largest ultrahigh-pressure (UHP) exposure was formed during Triassic collision between the Sino-Korean and Yangtze cratons. New apatite fission-track (AFT) data presented here from the UHP terrane, extends over a significantly greater area than reported in previous studies, and includes the (eastern) Dabie, the Hong'an (northwestern Dabie) and Tongbai regions. The new data yield ages ranging from 44 ± 3 to 142 ± 36 Ma and mean track lengths between ∼10 and 14.4 μm. Thermal history models based on the AFT data taken together with published 40Ar/39Ar, K-Ar, apatite and zircon (U-Th)/He and U-Pb data, exh..