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There are two types of gold ore in Shibaqinghao gold deposit, a mylonite ore and a quartz - vein ore. Pb isotope compositions for mylonite ore are characterized by lower Pb isotope ratios ranging from 16. 63 to 17.45 (206Pb/204Pb) , 15. 31 tol5.48 (207Pb/204Pb) , 36.52 to38.85 (208Pb/204Pb). They are scattered very close to a model curve of the mantle evolu-tion. These ratios suggest that gold in the mylonite ore might be derived from the country rocks, which originated directly in the upper mantle. Pb isotope compositions for quartz - vein ore are characterized by higher Pb isotope ratios ranging from 18.23 to 19.74 (206Pb/204Pb) , 15. 69 to 15. 89(207Pb/204Pb) , 38. 64 to 40. 13 (208Pb/204Pb). They are scattered very close to a model curve of the upper crustal evolution. These facts indicate that the gold in the quartz - vein ore might be relat-ed to some granitic magma generated in the crust.
There are two types of gold ore in Shibaqinghao gold deposit, a mylonite ore and a quartz - vein ore. Pb isotope compositions for mylonite ore are characterized by lower Pb isotope ratios ranging from 16.63 to 17.45 (206Pb / 204Pb), 15. They are scattered very close to a model curve of the mantle evolu tion. These ratios suggest that gold in the mylonite ore might be derived from the country rock, which originated directly in the upper mantle. Pb isotope compositions for quartz-vein ore are characterized by higher Pb isotope ratio ranging from 18.23 to 19.74 (206Pb / 204Pb), 15. 69 to 15. 89 (207Pb / 204Pb), They are scattered very close to a model curve of the upper crustal evolution. These facts indicate that the gold in the quartz - vein ore might be relat-ed to some granitic magma generated. in the crust.