江西金溪熊家山钼矿床铅、硫同位素特征及其地质意义

摘要

Xiongjiashan molybdenum deposit is another deposit which was found in recent years with considerable prospecting potential in northeastern Jiangxi-Wuyi uplift belt. S isotopic composition of sulfides from its ore is δ34S=0.19 ‰-6.42 ‰, and 4.29 ‰ in average. Pb isotopic composition of molybdenite is 208Pb/204Pb=38.424-40.102,207Pb/204Pb=15.585-15.611, 206Pb/204Pb=17.975-18.432, and averages 38.822, 15.596 and 18.128 respectively. Through comparing the Pb composition with those of Caledonian and Yanshanian granites, and the S and Pb isotopic composition with those of Yinshan Pb-Zn-Ag deoposit and Dexing Cu deoposit, as well as discriminating by tectonic diagram of Pb isotope, it is concluded that ore formation of Xiongjiashan molybdenum deposit is closely related with magmatic active of the Yanshanian granite, and the metallogenic material is principally derived from magmatic hydrothermal fluid. In addition to this, upper crustal rocks might have provided some metallogenic materials.%金溪熊家山钼矿床是赣东北地区-武夷隆起带上近年来发现的又一具有大型找矿潜力的矿床.矿石中硫化物的硫同位素组成δ34S=0.19‰～6.42‰，平均4.29‰；辉钼矿铅同位素组成：208Pb/204Pb=38.424～40.102，平均38.822；207Pb/204Pb=15.585～15.611，平均15.596；206Pb/204Pb=17.975～18.432，平均18.128.通过与燕山期和加里东期花岗岩的铅同位素，及银山铅锌矿床和德兴铜矿床的硫和铅同位素对比，以及铅同位素构造图解判别，认为熊家山钼矿床的形成与燕山期花岗岩浆活动密切有关，成矿物质主要来源于岩浆热液.除此之外，上地壳岩石也可能提供了一部分成矿物质.