Abstract:According to the combinations of metallogenetic elements and minerals assemblages, the Au-Ag deposits in the Middle-Upper Proterozoic Suberathem of the middle of northern margin of Yangtze Platform could be classified into four types: (1)Au-Ag-Pb-Zn type; (2)Au-Ag-Te type; (3)Au-quartz vein type; (4)Au-Ag-Pb-Zn-Ba type. The Yangpin formation and the upper Dangyuhe subformation, which belong to Wudangshan group, are regarded as favorable strata for Au-Ag mineralization by systematic assessments for Au-Ag bearing ability of the strata, as well as the felsic rocks of Bikou group. The metallogenetic physicochemical conditions and the stable isotopic compositions (S, Pb, H, O, C) have been studied in this paper. The sources of metallogenetic materials, origins of fluids and genesis of various deposits have also been studied.

Key words: Yangtze Platform  Middle-Upper Proterozoic Suberathem  Au-Ag deposit assessment physicochemical stable condition  isotopic geochemistry