个旧锡矿玄武质及花岗质岩浆载锡能力研究:来自高温高压实验岩石学的证据  

Sn-bearing capability studies of basaltic and granitic magma from the Gejiu tin deposit: evidence from high temperature and high pressure petrological experimentation

作　　者：张嘉玮[1,2,3] 朱成明[4] 罗泰义[3] 黄智龙[3] 马义波 王波[1,2] 唐佐其 

机构地区：[1]贵州省地质矿产勘查开发局 [2]贵州省地质调查院,贵州贵阳550004 [3]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵州贵阳550081 [4]中国科学院地球化学研究所地球内部物质高温高压实验室,贵州贵阳550081

出　　处：《矿物学报》2015年第2期159-166,共8页Acta Mineralogica Sinica

基　　金：中国地质调查局全国危机矿山接替资源找矿项目(编号:2008186);中国地质调查局西南岩溶区重要地层剖面调查项目(编号:12120114010001);中国地质调查局贵州1∶50000独山县、河寨、甲良、周覃4幅区域地质调查项目(编号:12120114072801)

摘　　要：对个旧锡矿的玄武岩和花岗岩进行了载锡能力的高温高压实验岩石学研究。结果表明:无论是花岗质还是玄武质岩浆,Sn4+都可以大量置换岩浆中的Si4+,形成富锡岩浆;个旧花岗质岩浆载锡最多可达约36%,而个旧玄武质岩浆载锡亦可达14.9%以上;当富锡的花岗质岩浆冷却时,岩浆将会出溶呈液滴状的锡的硫化物,表明花岗岩与锡矿有着直接的成因联系;而富锡玄武质岩浆由于快速淬火,且形成温度较高,不利于形成锡的矿物,但是所形成的玄武岩仍具备形成锡矿源层的条件。因此,锡矿的成矿地质体并不单一,花岗质与玄武质岩浆均可能成矿,关键在于岩浆在其形成或运移过程中,是否从源区或围岩之中获得大量的锡。Basalt and granite from Gejiu tin deposit were selected to carry out high temperature and pressure petrological studies on their respective capability of containing tin. The experimental results show that both in granitic and basaltic magma, Sn4+ can replace Si4+ abundantly, forming tin-rich magma. Gejiu granitic magma can carry up to 36% of Sn O2. Whereas, the basaltic magma also contain higher than 14.9% of Sn O2. Tin-bearing minerals are exsolved from magma in the form of liquid droplets as the granitic magma cools, indicating that the genesis of the tin deposit is directly related to the granite formation. Due to high temperature of formation and the quenching effect, no Sn-minerals can form in the basaltic magma. Yet despite this, the possibility of basaltic magma as an ore-forming source cannot be completely excluded. The genesis of the tin deposit may be related to both granitic and basaltic magmas. The key point is whether the magma absorbed a large amount of Sn during the melting process and transportation.

关 键 词：个旧锡矿 玄武岩 花岗岩 高温高压实验 矿床成因 

分 类 号：P618.44[天文地球—矿床学] P589[天文地球—地质学]