雪峰地穹金矿床的成因模式

GENETIC MODEL FOR GOLD DEPOSITS IN THE XUEFENG GEODOME

湖南西部雪峰地穹内现已发现的金矿床均赋存在前寒武系内,并具有明显的层控特征。研究表明:本区金矿床的形成经历了三个阶段,即地槽期原始金源层形成阶段(武陵-雪峰期)、地台期衍生金源层形成阶段(加里东-海西期)和地洼期改造成矿阶段(印支-燕山期)。这种改造成矿模式可能主要是通过地洼期构造热液沿滑脱构造及其次级裂隙带渗流、浸取金源层中的成矿物质而富集成矿的。

In the Pre-Sinian of the Xuefeng Geodome, West Hunan, there exist all of the found gold deposits obviously characterized by strata-bound deposits. Studies suggest that the deposits underwent three formation stages, i e., the formation of primitive gold-source beds in the geosyncline period (Wuling-Xuefengian), the formation of derived gold-source beds in the platform period (Caledonisn-Hercynian) and the transformation into deposits in the diwa period (Indosinian-Yanshanian). The gold deposits could be originated by that tectonic hydrothermal solution in the diwa period filtrated along the detachments and their secondary fissurcs and extracted ore—forming materials from the gold-source beds.