中文摘要:浅成-次火山岩是许多斑岩型和斑岩-浅成低温热液复合型铜、金矿床矿质和流体的重要来源,斑岩体初始岩浆的Cu,Au丰度,Cl,F含量及岩浆结晶时的氧逸度是其能否最终形成含Cu,Au流体的关键因素。黑云母是浅成-次火山中酸性侵入体中最常见的铁镁矿物,含有较丰富的Cu,Au及挥发分Cl,F,其Fe3+/(Fe3++Fe2+)比值可以反映其结晶时岩浆的氧化还原状态,尤其是斑晶黑云母往往形成于岩浆流体出溶和去气作用发生之前,它能灵敏地指示其母岩浆的初始Cu,Au丰度和Cl,F含量及氧化还原状态,因此,可以作为成矿物质、成矿流体来源的理想示踪矿物,并可用于评价浅成-次火山侵入体的成矿潜力。在一些斑岩型铜、金矿床和斑岩-浅成低温热液型金、铜矿床分布区开展浅成-次火山侵入体黑云母的成矿示踪研究,对于解决矿床成因和指导找矿实践均具有重要意义。
中文关键词:浅成-次火山岩,黑云母,铜金成矿示踪
Abstract:Hypergene-subvolcanic plutons serve as important sources of ore-forming materials and fluids in many porphyry-type and epithermal Cu (Au) ore deposits. Cu and Au abundances, concentrations of such volatiles as Cl, F and S and oxygen fugacity (f02) of the initial magma are key factors controlling the formation of Cu- and Au-bearing fluids during the Iate magmatic stage. Biotite is the most common Fe-Mg mineral in the intermediate-acidic hepergene-subvolcanic plutons; its phenocryst composition can usually show initial Cu, Au abundances and Cl, F contents of the parent magma, whereas the Fe3+/(Fe2++Mg2+ ) ratio of biotite may indicate the relative oxygen fugacity of the magma. Biotite can therefore be used as an ideal tracer mineral for Cu and Au mineralization in hypergene-subvoh:anic rocks. It is practical for us to carry out an investigation with biotite as a tracer of Cu, Au mineralization in some areas of hepergene-subvolcanic rocks so as to better understand ore genesis and guide ore exploration.
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基金项目:国家重点基础研究项目(编号:G1999043200)和国家自然科学基金(49902007、49973022)、南京大学等学校重点实验室访问学者项目
引用文本:
熊小林,石满全,陈繁荣.2001.浅成-次火山岩黑云母Cu,Au成矿示踪意义[J].矿床地质,20(2):107~111.2001.Biotite as A Tracer of Cu and Au Mineralization in Hypergene-Subvolcanic Plutons[J].Mineral Deposits20(2):107~111
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