湘西沃溪金锑钨矿床矿化蚀变带有机质特征初探

STUDIES OF ORGANISM ON MINERALIZED-ALTERATION ZONES OF Au-Sb-W DEPOSIT, WESTERN WOXI, HUNAN, CHINA

本文以矿床地质特征为基础,对赋矿围岩的有机质特征进行了初步探讨。在热液作用下,岩石中的Au^+、Au^(3+)等组分被有机质还原,有机质转变为二氧化碳。未蚀变岩石、钨矿化蚀变岩石和金锑矿化蚀变岩石的有机质热解色谱谱形、有机质热解参数、有机质成熟度等都有一定差别。未蚀变岩石的热解烃呈一次突发式释放,有机质的最高热解温度、产率指数、降解潜率和烃指数较低,有机质的成熟度最低(位于未成熟区)。钨矿化蚀变岩石的热解烃呈两次缓慢式释放,有机二氧化碳含量较高,有机质类型指数较低,有机质的成熟度较高(位于油区)。金锑矿化蚀变岩石的热解烃呈一次缓慢式释放,有机质的最高热解温度、可溶烃量、产率指数、有效碳、降解潜率和烃指数都较高,有机质成熟度最高(位于气区)。

Based on the geological characteritics of the deposit, some natures of organism in ore wall rocks have been studied. With the action of hydrothermal solution, the main mineral-forming components Au+ and Au3+ are reduced by organism, and the organism turns into CO2. Unaltered wall rocks, altered wall rocks of W mineralization and altered wall rocks of Au and/or Sb mineralizations have different forms of pyrolytic chromatogram, pyrolytic parameters and maturities of organism. In unaltered rocks, the maximun pyrolytic temperature, productivity index, degradating potentiality and hydrocarbon index of the organic matter are low, and the organic maturity is the lowest of the all rocks (in unmature region). The procession of the release of pyrolytic hydrocarbon is a sudden change;In W altered rocks,the organ ic carbon content is high, the type index is low, and the organic maturity is high (in the oil region). There are two times of unsudden release of pyrolytic hydrocarbon in the rock; In Au and/or Sb altered rocks, the maximum pyrolytic temperature, soluble content of hydrocarbon, yield index, effective carbon, degradation potentiality and hydrocarbon index are high, and the organic maturity is the highest (in the gas region). The pyrolytic hydrocarbon is, released unsuddenly.