摘要
皖南东源钨钼矿位于安徽省祁门东源境内,是该地区目前已知规模最大的钨钼矿床。钨钼矿体主要产于花岗闪长斑岩体内及其接触带附近,以细脉浸染状和浸染状矿化类型为主。流体包裹体地球化学研究表明,气相成分主要为H2O和CO2,含少量C2H4、N2、CH4等,液相成分以Ca2+、Na+、SO24-、Cl-为主,K+、F-次之,并含少量Mg2+、NO3-、Br-。矿床氢、氧、硫、铅稳定同位素组成研究表明,流体包裹体中水的δ18O水的含量范围为-0.498‰～3.102‰,δD水的含量范围为-85‰～-66‰,成矿流体主要为岩浆水与大气降水的混合物;黄铁矿的δ34SV-CDT值介于2.6‰～5.8‰,硫可能是由成矿流体从东源花岗闪长岩体中淋滤而来;铅同位素变化范围小,其来源具有明显的混合特征。成矿流体在成矿过程中,经历了不混溶或沸腾作用及其与被加热的大气降水的混合作用,改变了成矿流体系统的物理化学条件,引起体系含W和Mo络合物的不稳定,从而造成大量的成矿物质析出、沉淀,富集成矿。
Lying in Qimen City of Anhui Province,the Dongyuan W-Mo deposit is the largest W-Mo deposit so far discovered in this region.Its major W-Mo ore bodies are mainly hosted in granodiorite porphyry and near the contact zone,and mineralization is mainly of veinlet dissemination and dissemination types.Geochemical study of fluid inclusions shows that gas components of fluid inclusions are mainly H2O and CO2,with minor amounts of such components as C2H4,N2 and CH4.Liquid components of fluid inclusions are mainly Ca2＋,Na＋,SO2-4 and Cl-,with subordinate K＋ and F-and small amounts of Mg2＋,NO-3 and Br-.Studies of hydrogen,oxygen,sulfur and lead isotopes show that δ18Owater‰ values of the inclusions in quartz range from-0.498‰ to 3.102‰,and δDwater‰ values of quartz range from-85‰ to-66‰,suggesting that the ore-forming fluid was mainly derived from the mixed meteoric water and magmatic water.δ34SV-CDT‰ values of pyrite range from 2.6‰ to 5.8‰,implying that sulfur might have been derived from the Dongyuan granodiorite intrusion as a result of the leaching of ore-forming fluids.The lead isotope have a small range of values,and its source has obvious mixing characteristics.The ore-forming fluids in the metallogenic process experienced immiscibility or boiling and mixing with heated meteoric water,and thus changed the physical and chemical conditions of the ore-forming fluid system,causing unstableness of W and Mo complexes in the system and resulting in the precipitation,precipitation and enrichment of large quantities of ore-forming materials to form the ore deposit.
出处
《中国地质》
CAS
CSCD
北大核心
2011年第5期1334-1346,共13页
Geology in China
基金
安徽省国土资源厅公益性地质(科研)工作项目(2009-20)资助
关键词
东源钨钼矿床
流体包裹体
不混溶
同位素
皖南
Dongyuan W-Mo deposit
fluid inclusions
immiscibility
isotope
southern Anhui Province
