作　　者： ; ; ; ; ; ; ; ; ; ;

机构地区： 成都理工大学

出　　处： 《岩石矿物学杂志》 2013年第3期305-317,共13页

摘　　要： 尕尔穷铜金矿床位于西藏班公湖-怒江成矿带西段,是该带上近年来取得重大勘查突破的矽卡岩(斑岩)型铜金矿床。矿区产出的矽卡岩为典型的钙质矽卡岩,其矽卡岩矿物主要由石榴子石、辉石、硅灰石、绿帘石、绿泥石、符山石、矽线石等组成。电子探针分析结果表明,矿区石榴子石主要为钙铁榴石和钙铝榴石,辉石主要为透辉石,绿泥石可见铁绿泥石及铁镁绿泥石两种。石榴子石成分剖面显示其矿物组分随着石榴子石环带的变化而变化,表明矿区矽卡岩不是在一个完全封闭的平衡条件下形成的,指示矿床形成过程中热液流体具有多期多阶段性。尕尔穷矿区矽卡岩具有良好的分带性,表现为从靠近岩体的深部到靠近围岩的浅部具有石榴子石-透辉石相→透辉石-硅灰石相→硅灰石-绿帘石绿泥石相的分带特征,并伴随一定的矿化组合。典型矽卡岩矿物端员组分的识别及其Fe2+/Fe3+的比值计算结果表明,尕尔穷矿床形成于相对氧化环境。辉石组分中Mn/Fe比值的特征表明尕尔穷矿区具有一定的寻找钼矿的潜力。 Located in western Bangong Co-Nujiang River metallogenic belt, the Gaerqiong Cu-Au deposit is a skarn （porphyry） deposit whose exploration has achieved significant breakthrough in recent years. The skarns in the Gaerqiong ore district are typical calcareous skarn, and the skarn minerals include mainly garnet, pyroxene, wollastonite, epidote, chlorite, idocrase, and sillimanite. Electron microprobe analyses suggest that garnet com- prises mainly andradite and grossular, pyroxene is mainly composed of diopside, and chlorite includes ferrichb- rite and ferromanganese chlorite. The compositional section of garnet shows that mineral components vary with the change of garnet ring, suggesting that the skarns in the mining area were not formed in a completely closed equilibrium environment and the hydrothermal fluids had the multi-stage feature in the formation process of the deposit. The skarns in the Gaerqiong deposit have developed good zonation, characterized by zoning of garnet- diopside pha^-~diopside-wollastonite phase--＊wollastonite-epidote-chlorite phase, accompanied by rome mineral- ization combinations from the depth of the rock mass to the shallow part near the surrounding rocks. According to the result of Fe^2 ＋/Fe^3 ＋ calculating ratios, the Gaerqiong deposit was formed in a relatively oxidizing environ- ment, and the calculations of Mn/Fe ratios show that the Gaerqiong ore district has certain potential in search for molybdenum ore bodies.

关 键 词： 尕尔穷 矽卡岩 矿物学特征 西藏 地质意义

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