投稿时间：2012-02-21
修订日期：2012-03-11
中文摘要:云英岩析离体(包体)常见于南岭地区石英脉型(黑)钨矿床的成矿花岗岩体顶部附近,这些析离体多呈不规则椭球状,与寄主岩石花岗岩围岩界线明显,无与外面连通的脉体或构造,分布无规律。在湖南瑶岗仙钨矿床,云英岩析离体赋存于瑶岗仙岩体主体的灰色斑状碱长花岗岩Ⅰ中,大部分有分带,外带为云英岩化碱长花岗岩,富含辉钼矿,最高达5%以上,钠长石An平均为0.64;内核部分为云英岩,主要矿物组合为白云母、石英、萤石、黄玉、黑钨矿等,与黑钨矿石英脉相同,其黑钨矿含量最高达20%以上,属热液沉淀形成。云英岩析离体整体呈现出浆液过渡态流体作用的特征,是富Li-F碱长花岗岩浆液态分异作用的产物。与碱长花岗岩围岩相比,析离体中富集金属元素W、Mo、Bi及Li、Rb等元素,相对贫Co、Ni、Sr、Ba等元素,Cu、Pb、Zn的含量变化不明显。这种元素富集规律与区域岩浆演化趋势基本一致,显示岩浆晚期液态分异形成浆液过渡态流体是W等成矿元素富集的重要机制,但这一机制并不会导致Pb、Zn的富集,这一点不同于矽卡岩型钨矿床。石英脉型(黑)钨矿床的成矿地质体是灰色斑状碱长花岗岩Ⅰ,云英岩析离体是该岩体岩浆液态分异的结果,可以作为识别碱长花岗岩含矿性的重要标志(寻找石英脉型钨矿矿床)。
Abstract:The greisen inclusions usually irregularly occur near the top of the grey alkali feldspar granite in the tungsten deposits of the Nanling tungsten belt. They are mostly in irregular ellipsoid form and occur irregularly in the stage Ⅰ gray alkali feldspar granite with obviously boundary between them, and there exists no vein or fault as a channel. The outer part of the inclusion is greisenized alkali feldspar granite that contains very rich molybdenite (5%), in which the average An value of the albite is 0.64. The inner core of the inclusion is greisen with the assemblage of quartz, muscovite, fluorite, topaz, wolfamite etc., similar to things of the quartz vein formed from hydrothermal solution. The content of the wolfamite can be more than 20%. Compared with granite Ⅰ, the inclusion is rich in W, Mo, Bi, Li and Rb and poor in Co, Ni, Sr and Ba, with no obvious change of Pb, Zn and Cu. Studies of geology and geochemistry of the inclusions from the Yaogangxian tungsten deposit in Hunan Province show that the greisen inclusions were formed from liquid immiscibility of the Li-F alkali feldspar granite magma, which produced magmatic-hydrothermal transition state and hydrothermal solution. The liquid immiscibility seems to have been the main mechanism for concentration or mineralization of such elements as W, Mo and Bi, but without concentration of Pb and Zn, which is different from things in the skarn-type tungsten deposit. The formation of the vein-type tungsten deposit was related to stage Ⅰ gray alkali feldspar granite. The greisen inclusions constitute an important indicator for evaluating the granite in search for ore deposits.
keywords:geochemistry quartz vein-type magma separation liquid immiscibility tungsten deposit Hunan Province
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中图分类号：P618.67
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基金项目:本文得到全国危机矿山接替资源找矿项目"湘南-粤北地区锡钨多金属矿床成矿规律总结研究" (20089927);国家科技支撑课题"湖南锡田地区深部成矿岩体空间结构与成矿预测" (2011BAB04B08);广西"地质工程中心重点实验室建设"项目(11-031-20-K2)联合资助
引用文本：
祝新友,王京彬,王艳丽,程细音,何鹏,傅其斌,李顺庭.2013.石英脉型钨矿床中云英岩析离体及岩浆液态分异成矿研究——以湖南瑶岗仙钨矿床为例[J].矿床地质,32(3):533~544ZHU XinYou,WANG JingBin,WANG YanLi,CHENG XiYin,HE Peng,FU QiBin,LI ShunTing.2013.Characteristics of greisen inclusions in alkali feldspar granite of Yaogangxian tungsten deposit[J].Mineral Deposits32(3):533~544
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