辽宁省金矿床铅同位素组成特征及其地质意义

根据40多个金矿床近200件铅同位素组成数据讨论了辽宁省主要金矿化集中区不同类型金矿床铅同位素组成特征。辽西地区不同类型金矿床铅同位素图解上呈线性排列构成二次等时线或混合线。线金厂、下大堡和五龙金矿田等各自集中分布形成独立的等铅域。而猫岭等浊积岩建造金矿床则具有正常铅同位素组成,故其模式年龄可以代表成矿年龄。除个别矿床外,辽宁省多数金矿球矿石铅及与其有关花岗岩类岩石铅皆源自再活化的下地壳或者为下地壳和上地幔的混熔产物。

LEAD ISOTOPE FEATURES OF GOLD DEPOSITS OF LIAONING PROVINCE AND ITS GEOLOGICAL SIGNIFICANCE

According to nearly 200 data of Pb-isotope from more than 40 gold deposits, this paper has discussed the features of Pb-isotope compositions of different types of gold deposits in major gold concentrated zones of Liacning Province. The points of different type gold deposits in West Liaoning plotted on the Pb-Pb isotope diagrams distribute in linear array and form the 2nd-stage isochrone or the mixing line. The points of Xianjinchang, Xiadapu, and Wulong gold fields plotted on that distribute concentrically and form seperate isoplumb fields.ore-Pb of Maoling type turbidite-hosted gold deposits possess ordinary Pb-isotope compositions, so that their Pb-isotope model ages may-rep resent metallogenic ages. Except for a few deposits, the ore-Pb of gold deposits of Liaoning and the rock-Pb of granitoid related to them were derived from mobilized lower crust or were of mantle-crust mix.