江西永平铜矿下盘网脉状矿化的流体包裹体研究

Ni P,Tian JH,Zhu XT,Ling HF,Jiang SY and Gu LX.2005.Fluid inclusion studies on footwall stringer system mineralization of Yongping massive copper deposit,Jiangxi province,China.

永平块状硫化物矿床下盘脉状矿化的流体包裹体的温度介于220～400℃,原始流体盐度5.1～9.3wt.%NaCl。第一阶段脉状矿化形成于较低的温度范围(集中于220～320℃),此后流体温度逐渐升高,形成了第二阶段脉状矿化(240～400℃),最后流体温度稍微降低形成了第三阶段脉状矿化(290～370℃)。在演化过程中流体盐度也发生变化。形成第一脉状矿化时流体盐度较高(为6～9wt.%NaCl)。第二阶段脉状矿化时流体盐度变化不大(5.1～9.1wt%NaCl),但该阶段流体明显发生过沸晦作用,造成了端员组分的流体盐度分别为1.2～3.3 wt%NaCl 和41.2～45.5wt%NaCl。第三阶段矿化脉的形成时,流体的盐度有所降低(3.5～7.9wt%NaCl),也可见到局部的沸腾作用。三阶段脉状矿化脉石英流体包裹体的 Cl^-和SO^2的含量从第一阶段到第二阶段明显增高,到第三阶段降低;Na^+、K^+从第一阶段到第二阶段明显增高,到第三阶段有所降低。三阶段脉状矿化中的流体包裹体中均含有微量的二氧化碳(CO_2)、硫化氢(H_2S)和氮气(N_2)等挥发组分,其中第二阶段脉状矿化中的挥发份相对其它两阶段脉较为富集。

Yongping copper deposit, Jiangxi province, China, is a sedimentary-hosted massive sulfide deposit. It is hosted in the Yejiawan Formation （middle-Carboniferous period） and located in Xinjiang sedimentary basin controlled by Qiantangjiang-Xinjiang fault depression. Stratiform ore-body is the majority of the deposit. There are at least three stages of stringer veins underlie the stratiform ore-bodies. The first stage vein mainly consists of pyrite and quartz. The second stage vein was mainly made of pyrite, chalcopyrite and quartz. The third stage vein was mainly composed of calcite, few quartz and pyrite. Fluid inclusion studies on the stringer veins show that the homogenization temperature and primary salinities of fluid inclusion are 220 ～400℃ and 5.1 ～ 9.3 wt. % NaCl, respectively. The first stage of stringer vein formed in relatively lower temperature range（ 220 ～320℃ ） , then the temperature of fluid rose gradually and formed the second stage stinger vein （240 ～ 400℃ ） , at last , the temperature of fluid dropped slightly and formed the third stage stringer vein（290～370℃）. The salinities of fluid are also changed during the evolution of fluid. The first stage vein have a relatively higher salinities（6～9 wt. % NaCl）. The stage remain just as the same salinities as the first stage vein （5.1～9. 1wt% NaCl） , boiling had happened during this stage and result in the two end member fluid with the salinities of 1.2～3.3 wt% NaCl and 41.2～45.5 wt% NaCl respectively. During the formation of the third stage vein, the salinities of the fluid dropped to 3.5～7.9 wt% NaCl, and boiling phenomena can be seen in the restricted part of the vein.. The content of Cl^- , SO4^2- , Na^＋ and K^＋ in fluid rose from first stage to send stage vein and then dropped to the third stage vein. The trace volatile, such as CO2, H2S and N2 existed in all three stage stinger veins, but enriched in the second stage vein comparing to other two stage veins.