华南地区花岗岩特征及其与铀成矿地质作用

Characteristics of granites and their geological role in uranium mineralization in South China

华南地区分布有大面积的各个时期的花岗岩,亦是我国最大的花岗岩铀成矿省。从花岗岩形成年代、地球化学特征等对华南各个时期花岗岩综合分析,在此基础上进一步归纳总结各个时期花岗岩与铀成矿的关系。结果表明:加里东期花岗岩主要形成于460~410 Ma,以过铝质S型花岗岩为主,其次为I型花岗岩;印支期花岗岩主要形成于251~209 Ma,大多数印支期花岗岩属于准铝质-过铝质、高钾钙碱性花岗岩,以S型和I型花岗岩为主,常与燕山期花岗岩形成复式岩体;燕山期花岗岩主要形成于200~97 Ma,以S型花岗岩为主。铀成矿主要形成于燕山期,加里东期、印支期花岗岩为铀成矿提供铀源,燕山期小岩体为铀成矿提供部分热源。

Large area granites of various geological periods occurred in South China,which made this area the largest granite-uranium metallogenic province in China.Based on the comprehensive analysis of the granite formation age and geochemical characteristics,this paper summarized the relationship between various periods granite and uranium mineralization.The result showed that Caledonian granites were mainly formed in 460~410 Ma,mainly belongs to peraluminous S-type granites,followed by I-type granites.Indosinian granites were mainly formed in 251~209 Ma,mainly belongs to para-aluminous-peraluminous,high-potassium calc-alkaline granites,dominated by S-type and I-type granites,which often form compound intrusions with Yanshanian granites.Yanshanian granites were mainly formed in 200~97 Ma,mainly belongs to S-type granite.Uranium mineralization was mainly formed in the Yanshanian,Caledonian and Indosinian granites provided uranium sources for uranium mineralization and Yanshanian small intrusions provided part of the heat source for mineralization.