论文部分内容阅读
丽州金-银矿区位于汉城东南约60km的朝鲜半岛前寒武纪京畿变质岩带内。该矿区的矿山沿含金热液石英脉分布,这些石英脉穿切了早元古代眼球状片麻岩和中生代花岗岩。矿化分三个阶段(Ⅰ阶段、Ⅱ阶段和碳酸盐阶段),这三个阶段的矿化均充填早期的断层角砾岩带。流体包裹体资料表明,含硫化物-石英的Ⅰ和Ⅱ阶段从早期高温(约350℃)演化至后期较低温度(约180℃)。成矿后的碳酸盐阶段的流体包裹体资料反映出热液流体的温度更低(220—190℃),盐度更低(4—5当量％NaCl)。 流体包裹体和稳定同位素证据证明,银金矿、辉铜银矿、辉银矿、方铅矿和闪锌矿在温度为285—185℃时,从盐度为14.0—2.6当量％NaCl的流体中沉淀出来。流体包裹体的沸腾证据说明,Ⅰ和Ⅱ阶段矿化期间压力小于100bar,相当于深度为500的岩石静压力和1250m的静水压力。 Ⅰ阶段硫化物的硫同位素组成随共生时间而系统地减少,算出的δ~(34)S_(H_2S)值从7.7‰降至0.7‰。流体的硫酸盐/硫化物比值的逐渐增大很可能是由于沸腾时H_2S的丢失以及温度的降低造成的。不仅使δ~(34)S_(H_2S)值随时间而系统地减少,而且可能也导致金因Au(HO)_2~-分解而沉淀。 丽州矿区热液流体的氢和氧同位素值与以大气降水为主一致,而接近于未交换的大气降水值。这些值与南朝鲜其他?
The Li-Jin gold-silver mine is located in the Precambrian Gyeonggi metamorphic belt of the Korean peninsula about 60 km southeast of Seoul. The mines of the mine are distributed along the gold-bearing hydrothermal quartz veins, which cut the early Proterozoic ophthalmic gneisses and Mesozoic granites. Mineralization is divided into three stages (stage Ⅰ, stage Ⅱ and carbonate stage). The three stages of mineralization are filled with early fault breccia belt. Fluid inclusion data indicate that the sulphide-quartz phases I and II evolved from the early high temperature (about 350 ° C) to the late low temperature (about 180 ° C). The fluid inclusions in the carbonate phase after mineralization reflect the lower temperature (220-190 ° C) and lower salinity (4-5 equivalent% NaCl) of hydrothermal fluids. Fluid inclusions and stable isotope evidence show that silver, gold, feldspar, galena, galena and sphalerite at a temperature of 285-185 ℃, from the salinity of 14.0-2.6 eq% NaCl In the precipitation. The evidence of fluid inclusion boiling suggests that the pressure during the mineralization of stages I and II is less than 100 bar, corresponding to a rock static pressure of 500 and a hydrostatic pressure of 1250 m. The sulfur isotopic composition of the sulphides in stage Ⅰ systematically decreases with the intergrowth time, and the calculated δ ~ (34) S_ (H_2S) value decreases from 7.7 ‰ to 0.7 ‰. The gradual increase in the sulfate / sulfide ratio of the fluid is most likely due to the loss of H 2 S during boiling and to the decrease in temperature. Not only the δ ~ (34) S_ (H_2S) value decreases systematically with time, but also the gold may be precipitated by Au (HO) _2 ~ - decomposition. Hydrogen and oxygen isotopic values of the hydrothermal fluids in the Lizhou mining area are consistent with the predominantly atmospheric precipitation but close to the untransformed atmospheric precipitation values. What is the other value with South Korea?