摘要
梅仙式铅锌矿床是在大陆裂谷环境下形成的，有明显的块状硫化物矿床特征。矿化受震旦系龙北溪组绿片岩控制。矿体里似层状，与围岩产状一致。绿片岩原岩是一套含板内拉斑玄武岩的火山沉积建造。矿物组合和 Ｚｎ／Ｐｂ比值有分带性。层状矿体下盘有脉状、网脉状矿化和蚀变带。矿石有特征的结构构造。硫以幔源为主，铅是幔壳混合成因，矿液以海水成因为主．可能有少量雨水、岩浆水等渗入，反映物质的多来源和成矿受多种地质事件的叠加改造。本式矿床可与火山岩容矿型的加拿大新不伦瑞克省的块状硫化物矿床类比，也可作为广义华南型的一个亚型。
Meixian- type lead and zinc ore deposits were formed in a continental rift, with the distinct characteristics of massive sulfide deposits. Their mineralizations were controlled by the greenschists of Lower Sinian Longbenxi formation, and the orebodies, as strait form, are conformable to their host rocks. The greenschists originated from a series of volcanic - sedimentary formations with intercalated intracontinental tholeiites. Zoning is shown on both mineral assemblages and Zn/Pb ratios. There is a vein and network zone of mineralization and alteration below some stratiform orebodies. Ore textures and structures are typical of massive sulfide deposits. The sulfur originated from mantle, the lead from the mixture of mantle and crust sources, and the hydrothermal solution mainly originated from sea water, possibly combined with a small amount of meteoric and magmatic water. These imply that minerogenic materials are characteristic of multiple sources, and that mineral deposits were resulted from superimposition and transformation of multiple geological events. This type of ore deposits can be compared with the massive sulfide deposits hosted in volcanic or metamorphosed volcanic - sedimentary formations in New. Brunswick, Canada. In a broad sense, however, it can be regarded as a subtype of Huanan type.
出处
《火山地质与矿产》
1999年第3期172-180,共9页
Volcanology & Mineral Resources
基金
中国有色金属工业总公司地质勘查总局资助! 96- D- 40
