摘要
银山多金属矿床与燕山中期(129Ma)陆相火山岩-次火山岩有关。矿床及围岩蚀变具有明显的分带性和成矿阶段性。稀土元素及同位索资料表明:英安斑岩岩浆来源于上地幔或下地壳,为大陆拉斑玄武岩演化而成;成矿溶液以岩浆热浪为主,混合部分大气降水;在铅构造模式图上,其矿石铅大多为正常铅,少数样品出现钍铅混染。地质构造发展史及地层元素丰度值表明,双桥山群在经受变质作用后,除析出Au元素外,同时也析出大量Pb,Zn等成矿组分。
The Yinshan polymetallic deposit is related to the mid-Yenshanian(129 Ma) continental volcanic and subvolcanic rocks. Both orebody andwallrock alteration have obvious zoning and the mineralization may bestage-by-stage. The study on REE and isotopes shows that: the magma ofdacite porphyry is formed in the upper mantal or the lower crust as aresult of evolution of continental tholeiite; the ore-forming fluid mainlyconsists of magmatic solution mixed partially with meteoric water; on theplot of isotope composition, the lead is mostly normal Pb, only a few ofsamples indicate some Th-Pb contamination. According to the tectonichistory and abundance of elements in this area, it is considered thatShuangqiaoshan Group not only may provide Au, but also is the importantsource bed of elements of Pb, Zn, ect.
