福建沙县华口矿区变质岩层的成矿性研究

Study on metallogenesis of metamorphic rock stratum in Huakou Orefield,Sha County,Fujian Province

万全群是福建省重要的矿源层,但该群在华口银多金属矿床的形成过程中是否提供成矿物质来源并不清楚。笔者通过电子探针、硫同位素等多个方面对变质岩层的成矿性进行分析,研究表明：1）变质岩层中磁黄铁矿和黄铁矿的分布受热液充填所致,两者Cu、Pb、Zn的含量变化与矿物之间的交代关系有关,此次热液活动与银矿化没有直接关系,依据磁黄铁矿和黄铁矿的分布来找矿是不合理的;2）华口银多金属矿其硫化物的δ34S值在-1‰~2.5‰范围内变化,指示成矿流体的硫源单一,也显示出深部岩浆来源的特征,说明该矿的矿体均为同源同期形成;3）依据构造找矿可行性更高。

Wanquan Group is important as source bed in Fujian Province, but it is not clear whether Wanquan Group supplied ore-forming material during the formation of Huakou Silver Polymetallic Deposit. By EPMA and Sulfur Isotope Analysis, the research about metallogenesis of metamorphic rock stratum shows that： 1）The distribution of pyrite and pyrrhotine in metamorphic rock stratum is due to hydrothermal fluid filling. The content varia- tion of Cu, Pb, Zn in pyrite and pyrrhotine is associated with metasomatism between minerals, and there is no direct relationship between the silver mineralization and hydrothermal activity. Thus, prospecting based on the distribution of pyrrhotite and pyrite is unreasonable. 2）The 334S value of sulfide changes between -1%0 and 2.5%0 in Huakou Silver Polymetallic Deposit, which indicates that sulfur source of ore-forming fluid is single, magma is derived from deep source and all deposits formed homologously during the same period. 3）Prospecting based on structure is more feasible.