滇西北红山—红牛铜矿成矿物源:矿物学和稳定同位素约束

发布时间：2018-05-14 05:14

  本文选题：矿物学 + 稳定同位素　； 参考：《地学前缘》2017年06期

【摘要】：本文研究了中甸弧南段红山—红牛铜矿主要夕卡岩矿物石榴石和辉石成因矿物学特征,显示矿区石榴石为钙铁-钙铝石榴石系列,早期多为钙铁榴石,晚期为钙铝榴石。矿区部分石榴石在背散射光下可以观察到明显的环带结构,钙铝榴石和钙铁榴石含量差别越大环带越明显。矿区辉石主要为次透辉石和少量的透辉石,表明夕卡岩早期成矿流体为高温、酸性和高氧逸度环境。矿区黄铁矿强富铁亏硫且Co/Ni1,黄铜矿S、Fe和Cu含量较稳定只含有少量的C、Ni和Se,均指示为高温岩浆热液成因。金属硫化物34S众值出现在3.8‰~5.6‰,同时代的石英二长斑岩34S在4.7‰~7.8‰,表明硫主要来自石英二长斑岩。金属矿物和石英二长斑岩铅同位素特征表明,铅主要来自上地壳。石榴石δ~(18)O_(V-SMOW)=6‰~8.8‰,成矿流体δ~(18) OH_2O=4.6‰~7.8‰,反映成矿流体主要来自岩浆热液,且成矿流体存在明显的沸腾作用。夕卡岩矿体中的方解石和围岩方解石C-O同位素研究,指示块状硫化物中的方解石来自岩浆流体,含有硫化物细脉的围岩大理岩中的方解石来自围岩的再结晶作用。
[Abstract]:The mineralogical characteristics of the major skarn minerals garnet and pyroxene in Hongshan-Hongniu Copper Mine in the southern segment of Zhongdian arc have been studied in this paper. It is shown that garnet is a series of calcium iron and calcium aluminum garnet, most of which are calcium iron garnet in the early stage and calcium aluminum garnet in the late stage. The ring structure of some garnet in mining area can be observed under backscattering light. The larger the difference between calcium aluminite and calcium iron garnet is, the more obvious the ring zone is. The pyroxene is mainly subdiopside and a small amount of diopside which indicates that the early skarn ore-forming fluid is high temperature acid and high oxygen fugacity environment. Pyrite is rich in iron and sulfur, and the contents of Fe and Cu in chalcopyrite are stable, and only a small amount of Ni and See are found, indicating the origin of high temperature magmatic hydrothermal solution. The results show that the metal sulfides (34s) appear in the range of 3.8 鈥，

本文编号：1886498