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绿泥石化是华南热液铀矿床重要的蚀变类型之一。本文通过对南岭中段黄沙矿区223铀矿床绿泥石的岩相学和电子探针成分分析,区分出4种产出状态的绿泥石,识别了绿泥石的化学成分类型,计算了绿泥石的形成温度、n(Mg)/n(Fe+Mg)等相关指数,讨论了绿泥石形成机制环境及其与铀成矿的关系。研究表明223铀矿床绿泥石主要分为黑云母蚀变型、长石蚀变型、裂隙充填型和铀矿共生型4种产出类型,为富铁的蠕绿泥石,形成于还原环境,形成温度为200～282℃,属于中温热液蚀变;绿泥石的形成机制主要有溶蚀-沉淀结晶和溶蚀-迁移-沉淀结晶2种方式。绿泥石化改变了岩石物理-力学性质、原岩中铀的赋存状态,提供了成矿热液部分铀源和有利于铀富集成矿的地球化学环境。
Chlorite is one of the important types of alteration in hydrothermal uranium deposits in South China. Based on the petrography and electronic probe analysis of chlorite from 223 uranium deposit in the Huangsha mining area in the middle part of Nanling area, four types of chlorite in output status were distinguished and the chemical composition type of chlorite was identified. Chlorite formation temperature, n (Mg) / n (Fe + Mg) and other related indices, the formation mechanism of chlorite environment and its relationship with uranium mineralization were discussed. The results show that the chlorites in 223 uranium deposits are mainly divided into four types of biotite alteration, feldspar alteration, fissure filling and uranium coexistence. They are iron-rich vermiculite formed in the reducing environment , The formation temperature of 200 ~ 282 ℃, belong to the mesothermal hydrothermal alteration; chlorite formation mechanism mainly dissolution - precipitation crystallization and dissolution - migration - precipitation crystallization two ways. Chlorite changed the physical-mechanical properties of rocks, the state of uranium in the original rocks, provided part of uranium source for hydrothermal fluids and geochemical environment conducive to uranium enrichment and mineralization.