Fig. 4 A) 187 Re/ 188 Os vs. 187 Os/ 188 Os isochron diagram of pyrite separates from the E’touchang deposit. B) 87 Rb/ 86 Sr vs. 87 Sr/ 86 Sr isochron diagram of single-grain pyrite from the E’touchang deposit.

Fig. 3 Hand specimen photographs and SEM images of euhedral pyrites from the E’touchang deposit. A) Massive magnetite ores crosscut by hematite-chalcopyrite-pyrite veins, indicating late emplacement of hematite and sulfides. B) Banded hematite ores overprinted by late pyrite-chlorite-carbonate

Fig. 7 Geologic cross section of the Tangdan deposit, illustrating preferential mineralization along the upper and lower contacts of the Luoxue Formation and within carbonaceous slate of the lowermost E’touchang Formation (modified from Gong et al., 1996 ).

Fig. 1 A) Tectonic map of South China. B) Simplified geologic map of the Kangdian metallogenic province showing distribution of the IOCG deposits (modified from Wu et al., 1990 ). C) Geologic map of the Yinachang-E’touchang region (modified from 1:50,000-scale geologic map).

Fig. 8 Images of mineralized rocks from the Tangdan deposit. A. and B. Stratiform disseminated and veinlet chalcopyrite and bornite along beds and stylolites in bleached and silicified stromatolitic dolostone. This texture is referred to as “horsetail-like.” C. Oval concentrations of copper

at the Tangdan mine. The insert photo is a scan of a thin section from these rocks showing fluidization structures. C. Algally banded dolostone of the Luoxue Formation from the Tangdan deposit, showing typical pale-buff color of weathered rocks. The gray bands that parallel and crosscut bedding are silicified