Tectonic setting of the low-grade metamorphic rocks of the Dabie Orogen, central eastern China

The tectonic setting on both the northern and southern sides of the Dabie Mountains reveals that low-grade metamorphic rocks are important constituents produced by the subduction of the oceanic crust prior to collision between the Sino-Korean and Yangtze cratons. The Zhangbaling Group/Mulanshan schist is a pre-Ordovician oceanic crust. The Sujiahe and Xinyang/Foziling Groups are trench sediments of the Ordovician-Devonian age, and constitute an accretionary prism associated with subduction. The Yangshan coal measures/Meishan Group was a forearc basin sediment of Carboniferous age, and was overthrust by the accretionary prism during collision. The Susong Group is composed of passive continental margin sediments of the Yangtze craton. Backarc basin sediments are postulated to be concealed by Mesozoic–Cenozoic sediments to the north of the Dabie Mountains. High-ultrahigh pressure terrains are exotic tectonic slices exhumed from depths, located between low-grade metamorphic rocks, and disturb the integrity of the earlier subduction orogen. Subduction occurred during the Ordovician to Devonian periods, and collision initiated at the beginning of the Permian.

► Recognition of a remnant oceanic crust of Neopaleozoic age in southern Dabie Mountains. ► Distinguishing the forearc basin sediments from the accretionary wedge. ► Integration of regional structure, geophysical data, local structure, and metamorphic assemblages. ► Palinstatic reconstruction of the subduction of oceanic plate prior to collision between continent and island in the Dabie region.