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Chuangu Dai, Geological Survey of Guizhou Province, China (China)
Min Wang, Geological Survey of Guizhou Province, China (China)
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Recently geological mapping identified several Metamorphic Core Complex (MCCs) and associated extensional detachments in Fanjinshan and Congjiang areas of the eastern Guizhou Province, southwest China. The metamorphosed core complex systems are composed of an autochthone, sliding planes, and a slipped system. The autochtone is the Meso-Proterozoic metamorphosed crystalline basement; the slipped system is consisted of the Neo-Proterozoic to Paleozoic strata, and between the autochtone and slipped system is the major siding plane developed along the unconformity between the basement and the cover strata, which is displayed by bedding-paralleled normal fault, cataclasite, boudins, and mylonite or mylonitized rocks. There are several sub-sliding planes occurring along the stratigraphic sub-units boundaries?DAll structural criteria indicate a dip-down shear sense, likely having resulted from a crust-scale lithosphere extension. High-angle normal faults occur in the slipped strata system cutting across the lower-angle slipping systems. The normal faults have resulted in horst-graben structures, where some basins formed filling with the Later Paleozoic sedimentary rocks. Deposit-exploration indicated that the MCC-related extensional fault system played an obvious role for formation of the Au, Cu, and Pb-Zn deposits in the Fanjinshan area.
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