摘要
Based on the petrological studies of wall rocks, mineralized rocks, ores and veins from the Laowangzhai gold deposit, it is discovered that with the development of silification, carbonation and sulfidation, a kind of black opaque ultracrystalline material runs through the space between grains and amphibole cleavages, which is the product of fast condensing consolidation with magma mantle fluids turning into hydrothermal crustal fluids in the process of mineralization and alteration. It is thought that the water in ore-forming fluids mainly derived from magmatic water through research on H-O isotopes, and C as well as S isotopic compositions, has clear mantle-derived characteristics, and rock (mine) stones contain high 87Sr/86 Sr ratios, low 143Nd/144 Nd ratios and high 206Pb/204 Pb ratios, which also reflects the ore-forming fluids were derived from the metasomatically enriched mantle. In combination with the features of H-O-C-S isotopes and Sr-Nd-Pb isotopes described above, the ore-forming fluids of the Laowangzhai gold deposit in the northern part of the Ailao Mountains were derived mainly from the deep interior of the mantle, and their properties were transformed from magma fluids to hydrothermal fluids in the course of metasomatism and alteration, which initiated crust-mantle contamination simultaneously to be in favor of mineralization.
Based on the petrological studies of wall rocks, mineralized rocks, ores and veins from the Laowangzhai gold deposit, it is discovered that with the development of silification, carbonation and sulfidation, a kind of black opaque ultracrystalline material runs through the space between grains and amphibole cleavages, which is the prod- uct of fast condensing consolidation with magma mantle fluids turning into hydrothermal crustal fluids in the process of mineralization and alteration. It is thought that the water in ore-forming fluids mainly derived from magmatic water through research on H-O isotopes, and C as well as S isotopic compositions, has clear mantle-derived charac- teristics, and rock （mine） stones contain high 87Sr/86Sr ratios, low 143Nd/144Nd ratios and high 206pb/204pb ratios, which also reflects the ore-forming fluids were derived from the metasomatically enriched mantle. In combination with the features of H-O-C-S isotopes and Sr-Nd-Pb isotopes described above, the ore-forming fluids of the Laowangzhai gold deposit in the northern part of the Ailao Mountains were derived mainly from the deep interior of the mantle, and their properties were transformed from magma fluids to hydrothermal fluids in the course of me- tasomatism and alteration, which initiated crust-mantle contamination simultaneously to be in favor of mineraliza- tion.
基金
supported by the National Natural Science Foundation of China (Grant Nos. 40773031 and 40473027)
the Ph.D. Programs Foundation of Ministry of Education of China (Grant Nos. 20105122110010 and 20115122110005)
the Project of the State Key (Preparation Support) Disciplines of Mineralogy, Petrology and Mineral Deposit Geology of CDUT (Grant No. SZD0407)
