Features and genesis of Caledonian granites in the Wugongshan in the eastern segment of the northern margin of South China plate

Abstract：Gneissic granites are exposed over large tracts in the Wugongshan (Wugong Mountains) in the eastern “segment on the northern margin of South China. Previous studies suggested that these rocks belong to migmatites” of migmatitic origin. This study has verified that these rocks belong to syntectonic granites. On the basis of a study of the hierarchical units of the rocks, five units have been distinguished, which may be grouped into two super-units. The rocks have U-Pb ages of 462.3±3.2 Ma and 409.4±5.1 Ma respectively, belonging to Caledonian orogenic granites. After their formation they underwent overprinting and reworking of Indosinian-Yanshanian extensional-sliding superimposed structure.