乌克兰钠交代型铀矿床成矿特征及对中国龙首山铀矿床的启示  

Metallogenic Characteristics of Na-metasomatic Uranium Deposit in Ukraine and Their Enlightenment to the Longshoushan Uranium Deposit in China

作　　者：王泽鑫 宋昊[1,2] 陈友良 张成江[1,2] 李梅 WANG Zexin;SONG Hao;CHEN Youliang;ZHANG Chengjiang;LI Mei(Chengdu University of Technology,Chengdu 610059,Sichuan,China;Key Laboratory of Nuclear Techniques in Geosciences of Sichuan Province,Chengdu 610059,Sichuan,China)

机构地区：[1]成都理工大学,四川成都610059 [2]地学核技术四川省重点实验室,四川成都610059

出　　处：《大地构造与成矿学》2024年第6期1315-1329,共15页Geotectonica et Metallogenia

基　　金：国家自然科学基金项目(42173072);中国核工业地质局“铀资源勘查开发动态分析与项目优选(地D2103)”项目联合资助。

摘　　要：钠交代型铀矿床因独特的钠交代作用而得名,其铀资源量位于全球铀矿类型中第四位。乌克兰位居世界首位的钠交代型铀资源储量和典型的铀矿化特征使乌克兰中央铀成矿省成为研究该类型铀矿床的理想对象,同时乌克兰钠交代型铀矿床勘查程度、成矿理论研究程度均较高,对国内同类铀矿床的勘查开发及成矿理论研究具有借鉴意义。本文在总结乌克兰中央铀成矿省钠交代型铀矿床的成矿条件和成矿模式的基础上,将其与中国北祁连造山带龙首山地区的钠交代型铀矿床进行对比研究。与乌克兰印古尔地块长期处于稳定状态不同,北祁连造山带形成于早古生代阿拉善地块与祁连-柴达木地块的拼合背景下,大地构造背景上的差异导致了二者在触发富钠岩浆上涌的机制、赋矿岩体的岩性和矿物组合方面存在差异。但二者经历了相似的成矿过程:以钠交代为先导的一系列蚀变作用对岩体中的铀进行多次活化运移,最终在构造有利的部位富集成矿;二者具有高度一致的蚀变分带特征,及蚀变前后元素地球化学参数的相似变化趋势。乌克兰中央铀成矿省钠交代岩和深大断裂对钠交代型铀矿体具有良好控制作用,通过借鉴乌克兰钠交代型铀矿床的勘查、研究经验,及与我国龙首山地区钠交代型铀矿床的钠交代岩、矿体垂幅范围的对比研究,结合区域剥蚀程度分析,指出在龙首山地区深部仍有较好的找矿潜力。The Na-metasomatic uranium deposit was named for its unique Na-metasomatism.The uranium resources of this type of uranium deposits rank fourth in the world.Ukraine ranks first in the world in terms of Na-metasomatic uranium reserves.The high degree of exploration and extensive metallogenic investigations of the Ukrainian Na-metasomatic uranium deposits may have reference significance to the exploration and metallogenic study of similar uranium deposits in China.This paper summarizes the metallogenic conditions and models of the Na-metasomatic uranium deposits in the central Ukrainian uranium province and compares the characteristics of the Na-metasomatic uranium deposits in Ukraine and the Longshoushan metallogenic belt.Unlike the long-term stable state of the Ingul block in Ukraine,the North Qilian orogenic belt was formed through the assemblage of the Alxa block and the Qilian-Qaidam block in the Early Paleozoic.Differences in geotectonic backgrounds lead to discrepancies in the triggering mechanisms of Na-rich magma upwelling,and thus,differences in the lithology and mineral assemblage of ore-bearing rocks.However,both of them experienced similar metallogenic processes during which a series of Na-metasomatism remobilized and migrated uranium,resulting in uranium mineralization in favorable parts.Moreover,the deposits in Ukraine and China show similar alteration zoning and geochemical trends.Na-metasomatic uranium deposits in the central Ukrainian uranium province show the control of Na-metasomatic bodies and deep faults on uranium ore bodies.Based on the Ukraine’s exploration and research experience of Na-metasomatic uranium deposits,combined with the comparative study and analysis of regional denudation degree,it is pointed out that there is still good prospecting potential at the depth of 800-1000 m in the Longshoushan metallogenic belt.

关 键 词：钠交代型铀矿床 热液蚀变 成矿模式 乌克兰中央铀成矿省 龙首山成矿带 

分 类 号：P611[天文地球—矿床学] P612[天文地球—地质学]