摘要
长坑矿田金、银矿体主要产于下石炭统与上三叠统不整合面之下的硅质岩中,金、银矿体分离。金矿体主要为浸染状,富集As、Sb、Hg;银矿体主要为脉状,富集Cu、Pb、Zn。金矿体铅同位素组成与寒武纪—石炭纪地层及硅质岩的相同,银矿体铅同位素组成与金矿体的不同。金、银矿体的氢、氧、碳同位素组成也明显不同。银矿体Rb-Sr等时线年龄为70.4Ma。据上述特征,笔者认为长坑金、银矿床是不同成矿作用形成的,金矿主要是热水沉积形成,银矿主要是燕山期晚期改造形成。
Gold and silver orebqdies in the Changkeng ore district mainly in siliceous rocks and limestone immediately under the uncomformity between the Lower Carboniferous limestone and the Upper Triassic carbonaceous shale. Gold and silver orebodies are separated from each other. Gold mineralization, which is enriched in Hg. As and Sb occurs as disseminations in siliceous rocks; while silver mineralization, which is enriched in Cu, Pb and Zn, occurs as veins in siliceous rocks and limestone. Lead isotopic composition of gold mineralization varies in the same range as those of Cambrian to Carboniferous strata and the gold - hosted siliceous rocks. Lead isotopic composition of silver ore differs from that of the gold ore. Hydrogen, oxygen and carbon isotopic compositions of gold ore -forming fluids and silver ore -forming fluids differ from each other. The Rb - Sr isochron age of silver mineralization is 70. 4 Ma. It is concluded that the gold deposit resulted from hydrothermal - sedimentary processes, while the silver deposit from late Yanshanian reworking processes.
出处
《地质论评》
CAS
CSCD
北大核心
1998年第2期194-199,共6页
Geological Review
基金
中国科学院黄金重大项目
广东省基金
