南岭中段黄沙矿区223铀矿床绿泥石特征与铀成矿关系  

Characteristics of Chlorite and Its Relation with Uranium Mineralization of No.223 Uranium Deposit of Huangsha Mining Area in the Middle of the Nanling Mountains, China

作　　者：舒田田 潘家永[1] 钟福军 祁家明 黄广文[1] 

机构地区：[1]东华理工大学核资源与环境国家重点实验室培育基地,江西南昌330013 [2]核工业二九0研究所,广东韶关512026

出　　处：《矿物学报》2017年第6期737-745,共9页Acta Mineralogica Sinica

基　　金：国家自然科学基金项目(批准号:U1403292;41772066);中国地质调查局地质调查项目(编号:12120115035601);江西省研究生创新基金项目(编号:YC2016-B74)

摘　　要：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。Chloritization is one of the most important alteration types of hydrothermal uranium deposits in Southern China. Based on EPMA analysis and mineralogical study, chlorites in No.223 uranium deposit of Huangsha mining areain the middle of the Nanling Mountains are classified into 4 types. The chemical types of chlorite were divided; formation temperature and n（Mg）/n（Fe＋Mg） value were calculated, and the formation mechanism and it＇s relationship with uranium mineralization were discussed.The study found that the chlorites in No.223 uranium deposit is divided into 4 types including biotite alteration type, feldspar alteration type, fissure filling type and uranium symbiotic type. They are mainly Fe-rich prochlorite formed under the reducing condition; the temperature range of formation of chlorite is 200-282 ℃, belonging to the mesothermal alteration, and the formation mechanism is composed of dissolution-crystallization and dissolution-migration-crystallization. It is clear that chloritization not only changes the physical mechaical properties and the occurrence state uranium in rock, but also provides the part uranium source of ore-forming fluid and a favorable geochemical environment for uranium mineralization.

关 键 词：223铀矿床 绿泥石 铀成矿 形成机制 

分 类 号：P579[天文地球—矿物学] P611[天文地球—地质学]