滇东南建水铌稀土矿的矿物特征及研究意义

Ore Mineral Characteristics and Research Significance in Puxiong Niobium and Rare Earth Mine,Jianshui County,Yunnan Province

云南省建水县普雄风化壳离子吸附型铌稀土多金属矿的成矿母岩为燕山期碱性侵人岩,成因类型与A型花岗岩大致相当。矿石由3类矿物组成:残留造岩矿物及其次生矿物共有14种.占矿石总量的96.54%;稀土矿物和含稀土矿物共有14种,占矿石总量的0.20%;其他矿物共有18种,占矿石总量的3.19%。研究表明:矿石中的主要矿物与成矿母岩的矿物有明显成因联系,主要成矿母岩应属霞石正长岩;残留矿物与次生矿物在矿石中并存,反映了母岩的风化程度中等偏高;矿石的微量矿物组合具有碱性岩类风化壳离子吸附型稀土矿床特征,成矿元素主要为∑Ce,Nb,Zr;④矿石中磁铁矿远大于钛铁矿,成矿母岩应属磁铁矿系列。这些资料表明:研究矿石的矿物特征,对分析成矿母岩类型、矿石风化程度、稀土矿床类型、成矿母岩成因有较明显的作用。

The metallogenic parent rock of the weathering crust ion-adsorption niobium rare-earth polymetallic mine in Puxiong,Jianshui County,Yunnan Province is a Yanshanian alkaline intrusive rock,and its genetic type is roughly equivalent to that of A-type granite.The ore consists of three types of minerals:Residual rock-forming minerals and secondary minerals.14 types of minerals accounting for 96.54%of the total weight of the ore.Rare earth minerals and rare earth-containing minerals,14 types of minerals accounting for 0.20%of the total weight of the ore.18 types of other minerals accounting for 3.19%of the total weight of the ore.The following conclusions were drawn from the study:major minerals in the ore are closely related to the minerals of the parent mineral rock.The main metallogenic parent rock should belong to nepheline syenite.Coexistence of residual minerals and secondary minerals in the ore are moderate to high weathering degree of the parent rock.The trace mineral composition of the ore is characterized by alkaline rock weathering shell ion-adsorption rare earth deposits,and the ore-forming ele-ments are mainly LREE,Nb,and Zr.Content of magnetite in the ore is far larger than ilmenite,the parent rock should be magnetite series.These data indicated that the study of ore mineralogy has obvious effects on the analysis of the type of parent metallogenic rock,the degree of ore weathering,the types of rare earth deposits,and the genesis of parent metallogenic rock.