Tectonic implication of UHP rocks from the Dabie Mountains

Petrological, mineralogical, isochronological data accumulated in the last 4 years are summarized. The variations of lithology and protolith. as well as block-in-matrix structure of UHP (uHrahigh-pressure) rocks imply a metamorphic melange. Clockwise P-T paths of UHP rocks indicate that their formation and exhumation are related to collisional orogeny. Isochronological data indicate that the peak UHP metamorphism was during the Middle-Late Triassic. The exhumation rates, estimated according to P-T-t paths, show a multiple exhumation stages, with a high exhumation rate (3.3-3.6 mm/a) in the Middle-Late Triassic, a lower rate (0.7-1.1 mm/a) in the Early Jurassic, and a very low rate (0.15 mm/a) in the Middle Jurassic to Early Cretaceous. With these constraints, a hypothetical cross-section of the Dabie orogenic belt is constructed.