贵州天柱地区金矿地球化学特征及成矿作用探讨

Geochemistry characteristics and metallogenesis of gold deposits in Tianzhu,Guizhou

应用四级杆型电感耦合等离子体质谱(Q-ICP-MS)对黔东南天柱地区各典型金矿床(点)含金石英脉及近矿围岩的微量、稀土元素进行系统的测定,结果表明:其微量、稀土分布曲线与区域变质岩基本一致,表明金主要来源于区域地层。部分石英脉样品的稀土配分模式为"平坦型",轻重稀土分馏不明显,更接近上地幔或下地壳的稀土组成特征。同时,W、Mo等高温成矿元素的相对富集,暗示可能有深部岩浆活动影响了成矿。Y/Ho、Th/U的研究结果显示:成矿流体主要为变质水,部分矿床可能有大气降水的混入。综合分析认为:该区金矿床的成矿流体与成矿物质具多来源特征。

In this study,with Quadrupole-Inductively Coupled Plasma-Mass Spectrometry（ Q-ICP-MS）,we conducted systematic detection of trace elements and rare earth elements in auriferous quartz veins and wall rocks in typical gold deposits in Tianzhu,Southest Guizhou. The result showed that the distribution curve of trace elements and rare earth elements was in accordance with regional metamorphic rocks,indicating that the strata is the main source of gold. The distribution of rare earth elements in some quartz veins displayed a horizontal pattern,the difference between LREE and HREE was not significant,and the distribution pattern was closer to that in upper mantle or lower crust. The high-temperature ore-forming elements（ W,Mo,etc.） were relatively abundant,suggesting that there might be deep magmatic activities affecting the metallogenesis. Y/Ho,Th/U results showed that the main oreforming fluid was metamorphic water,and in some deposits there might be atmospheric precipitation. In conclusion,metallogenic fluids and ore-forming materials were of multiple sources in gold deposits in Tianzhu.