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湘南黄沙坪多金属矿床位于南岭构造带中段北缘,属于矽卡岩型矿床。根据矽卡岩产出状态、矿物共生组合及岩相学特征,从早期到晚期可划分为矽卡岩阶段、退化蚀变阶段、早期硫化物阶段和晚期硫化物阶段。矽卡岩矿物主要为石榴石、辉石、符山石等;金属矿物主要为白钨矿、辉钼矿、磁铁矿、方铅矿、闪锌矿等。电子探针分析结果表明,石榴石为钙铝-钙铁榴石系列,从早期到晚期,石榴石具有由钙铝榴石逐渐向钙铁榴石演化的规律。且钙铁榴石普遍发育震荡环带,而环带结构可持续记录钙铁榴石物理化学条件演化的过程。同时两种石榴石中均含Sn的成分,但钙铁榴石中Sn的含量明显高于钙铝榴石。辉石为透辉石-钙铁辉石系列,而且由内接触带向外接触带,辉石中Fe和Mn的含量有逐渐升高的趋势。矽卡岩矿物学特征及矿物成分的变化表明,成矿流体至少经历了两次氧化还原性质的转变。矽卡岩矿物学特征,对W(Sn)-Mo-Bi等多金属的矿化具有重要的地质指示意义。
The Huangshaping polymetallic deposit in southern Hunan is located in the northern margin of the mid-section of the Nanling structural belt and belongs to a skarn-type deposit. According to skarn output status, mineral assemblages and lithofacies, it can be divided into skarn stage, degenerated alteration stage, early sulphide stage and late sulphide stage from early to late stage. Skarn minerals mainly garnet, pyroxene, Fu Shan, etc .; metal minerals are scheelite, molybdenite, magnetite, galena, sphalerite and so on. The results of electron probe analysis showed that garnet is a series of Ca - Al - Ca - Fe garnets. From early to late, garnet has the regularity of evolvement from. In addition, the oscillatory zone is generally developed in the diatomaceous earth, while the zonal structure can continuously record the evolution of the physico-chemical conditions of the ore-garnet. At the same time, both of the two garnets contain Sn, but the content of Sn in the calcareous garnet is obviously higher than that of the attapulgite. Pyroxene is a diopside-calcium-iron-pyroxene series, and the content of Fe and Mn in pyroxenes gradually increases from the inner contact zone to the outer contact zone. Skarn mineralogical characteristics and mineral composition changes show that the ore-forming fluid has undergone at least two redox properties change. Skarn mineralogical characteristics of W (Sn) -Mo-Bi and other polymetallic mineralization has important geological significance.