摘要
Abstract
The Tieshan rock mass in the middle section of the Gan-Hang Tectonic Volcanic Rock Uranium Metallogenic Belt,as a typical representative of the granite-type uranium deposits within the Yangtze and Cathaysia ancient land suture zone,reveals a new mechanism of the volcanic rock-granite composite ore-forming system.Through field geological surveys,engineering exposures,and rock ore testing,it has been found that the uranium mineralization mainly occurs in the fine-grained biotite monzonitic granite of the Late Jurassic period,and is controlled by the combination of the nearly SN-trending silicified fracture zone and the lamprophyre vein.The main ore body of the No.58 mineralization point is plate-shaped(strike 330°,length>50m,average thickness 1.1m),with a uranium grade of 0.26％to 0.71％,and showing the alteration zoning characteristics of"silicification+hematitization → kaolinization → chloritization"from the inside to the outside.The research shows that:The uranium enrichment is controlled by the uranium source provided by the highly differentiated granite(K2O/Na2O>1.2)and the activation of volatile components such as F and Cl;The SN-trending fault system(the intersection of the Pingxiang-Guangfeng Fault and the Yiqian-Huanggangshan Fault)forms the ore-hosting space,and the ore body is located at the intersection of the secondary fracture zone and the lamprophyre vein□The hydrothermal alteration(silicification,hematitization)caused by the intrusion of the lamprophyre enhances the efficiency of uranium migration and precipitation.Prospecting and exploration work can be carried out in the hope of achieving breakthroughs in the exploration of granite-type uranium deposits.关键词
黑云母二长花岗岩/铀矿化特征/控矿因素/铁山岩体Key words
Biotite monzogranite/Uranium mineralization characteristics/Ore-controlling factors/Tieshan rock mass分类
地质学
