孟繁星，李礼，韦光景，黄卫

文章编号：1672-5603（2020）02-36-6

摘 要 湖南省南水山地区位于雪峰山-摩天岭成矿带，是我国南方最重要的铀成矿带之一。花岗岩具有高硅、富钾、富挥发份、贫铁、镁及铝，低钙、钠等特征属于中-强钙碱性岩系，具铝过饱和特点，明显负Eu异常，符合产铀花岗岩的特点。通过对研究区岩石类型、岩浆活动、断裂构造及热液活动的分析发现区内花岗岩铀矿类型为热液型-内接触带型铀矿，多期次强烈构造岩浆活动和多期次的热液蚀变活动促使铀矿在构造交汇部位汇聚，为铀的迁移创造了良好环境，为铀成矿创造了有利条件。

关键字 花岗岩型铀矿;成矿特征;控矿因素;热液型-内接触带型铀矿

中图分类号：P619.14文献标识码：A

The analysis of Metallogenic Characteristics and Ore-Controlling Factors of Granite-type Uranium in Nanshuishan Area

of Hunan Province

Meng Fanxing，LiLi，Wei Guangjing，Huang Wei

（Hunan Nuclear Industry Geological Survey Institute， Changsha Hunan 410016）

Abstract： Nanshuishan area of Hunan province is located in the Xuefengshan - Motianling metallogenic belt， which is one of the most important uranium metallogenic belts in southern China. Granite is characterized by high silicon， rich potassium， rich volatilization， low iron， magnesium and aluminum， and low calcium and sodium. It belongs to the medium-strong calc-alkaline rock series with the characteristics of aluminum sustriation and obvious negative Eu anomaly， which is in line with the characteristics of uranium-producing granite. Through the study of rock types， magmatic activity， analysis of the fracture structure and hydrothermal activity， it is found that granite-type uranium is a hydrothermal type - internal contact type uranium. More intense tectonic magmatic activity and hydrothermal alteration activities make uranium ore converge at the intersection of structures， which creates a good environment for the migration of uranium and creates favorable conditions for uranium mineralization.

keywords： granite-type uranium; metallogenic characteristics; ore-controlling factors; hydrothermal type - internal contact type uranium

0 引言

花岗岩型铀矿是指在空间和成因上与花岗岩体有着密切联系的热液铀矿化，矿体产于花岗岩体内部或外接触带附近的硅化破碎带内，呈现多期多阶段演化的特点，多产于印支、燕山及喜山期花岗岩内[1-3] 。近些年，已发现的新建桥铀矿点、井沙冲点及苗尔山矿田，位于雪峰山-摩天岭成矿带，与南水山地区花岗岩型铀矿在同一成矿带上，表明该地区具有巨大找矿空间。

1 地質背景

1.1 区域地质背景

研究区位于郴州-新化断裂和城步-新化断裂的交汇部位，褶皱和断裂构造十分发育。褶皱和断裂构造不仅是岩浆和热液频繁活动的场所，也是铀成矿物质频繁叠加的场所和矿体空间上交叉重叠的部位。以接触关系为依据，同位素年龄数据为参考，结合岩石学、岩石矿物学、岩石化学，稳定同位素及稀土元素和微量元素特征，将研究区花岗岩侵入体归并为两个同源岩浆序列和七个单元（图1）。……