【摘要】 湖南锡矿山锑矿床是目前世界上已发现的最大的锑矿床,其硅化非常发育且与矿化关系密切,根据硅化蚀变程度的强弱,从围岩到矿石大致划分为4个带:灰岩→弱硅化灰岩→强硅化灰岩→矿石。为揭示锡矿山锑矿的成矿过程及成矿流体信息,利用Isocon标准化方法,以Al₂O₃为惰性组分,对各蚀变带围岩及矿石的主、微量元素进行质量平衡计算。结果表明,热液蚀变过程中,Si、Sb、Li和Bi等大量迁入,而Ca、Mg、Na和大离子亲石元素Sr、Ba、Rb等大量迁出;成矿热液呈酸性并富硅,其中Hg、As、Au、Tl等元素含量极低,这可能是导致锡矿山锑矿床矿种单一的原因之一。稀土元素除Eu外,其他元素未发生明显的活化迁移,水岩反应并未影响原岩的稀土元素配分模式;蚀变岩及矿石中的Eu负异常可能表明成矿过程是在相对还原的环境下进行的。更多还原

【Abstract】 The Xikuangshan Sb deposit is the largest Sb deposit in the world. The silicification alteration is well developed in the deposit,which is closely associated with Sb mineralization. According to the alteration degree of wall rocks,four alteration zones are identified,including fresh limestone,weakly silicified limestone,strongly silicified limestone and highgrade ores. In this study,we carried out detailed elemental migration characteristics of wall rocks and ores from different alteration zones in order to decipher the nature of ore-forming fluids and mineralization process. The Isocon method is used to calculate the mass balance and Al₂O₃ compositions are regarded as immobile component. New results show that the majority elements including Si,Sb,Li and Bi are brought into wall rocks by hydrothermal fluids,whereas elements such as Ca,Mg,Na,Sr,Ba,Rb are significantly extracted out. The ore-forming fluids are acidic and silicic-enriched. Extremely low contents of Hg,Au,Tl and As may be responsible for the simple mineral assemblage in the Xikuangshan Sb deposit.REEs,except Eu,are not activated and migrated in such process and the REE patterns remain unchanged. Both altered rocks and ores have negative Eu anomalies,indicating that the mineralization took place in relatively reduced environment.更多还原