甘肃龙首山芨岭铀矿床矿化特征、蚀变矿化机制 及控矿构造研究  

Study on mineralization characteristics and alteration mineralization mechanism and ore-controlling structure at Jiling uranium deposit in Longshoushan of Gansu

作　　者：王伟 王江波 刘涛 韩栋昱 何佳军 李涛 WANG Wei;WANG Jiangbo;LIU Tao;HAN Dongyu;HE Jiajun;LI Tao(Research Institute No.203 of Nuclear Industry,Xianyang 712000,Shannxi,China)

机构地区：[1]核工业二〇三研究所,陕西咸阳712000

出　　处：《矿产与地质》2024年第1期42-52,共11页Mineral Resources and Geology

基　　金：中国核工业地质局铀矿勘查项目“甘肃省龙首山成矿带红石泉-青山堡地区铀矿资源调查评价与勘查”(编号:202220);陕西省自然科学基金项目"北秦岭成矿带东段古生代淡色花岗岩成因与铀成矿作用研究"(编号:2024JC-YBMS-235)共同资助。

摘　　要：芨岭铀矿床为甘肃省龙首山分布的典型铀矿床,对其进行深入研究有利于指导区内其他地区的找矿勘查工作。本文结合区内多年勘查工作取得的研究成果和资料,系统总结了芨岭矿床的铀矿化特征,在此基础上,对分带岩矿石的岩石地球化学以及控矿构造进行了综合分析,以探讨成矿流体的蚀变矿化机制与构造控矿机制。研究结果表明,芨岭矿床赋存于受马路沟断裂控制的岩体接触带附近,从岩体到矿体具有从斑状花岗岩-无矿化钠交代岩-异常钠交代岩-矿化钠交代岩-含矿化钠交代岩的分带现象,矿石发育钠长石化-赤铁矿化-碳酸盐化-绿泥石化为主的蚀变组合,成矿作用主要经历了两期热液蚀变,即早期的岩浆-热液自交代蚀变矿化与晚期叠加的外循环流体成矿富集蚀变,并分别以钠长石化和赤铁矿化为典型蚀变特征。矿体在空间上受到马路沟断裂及其次级断裂的控制作用,针对马路沟断裂的复杂性,通过大量深部钻孔查证,目前认为马路沟断裂受到古元古界白家咀子组大理岩残留体的影响分为两条大致平行的F 101和F 105断裂,两条断裂在深部残留体尖灭部位合二为一条陡倾断裂。综合分析认为马路沟断裂的次级断裂为赋矿断裂构造,主、次断裂构造夹持区是铀成矿的最有利部位,也是下一步找矿勘查工作的重点靶区。Jiling uranium deposit is one of the typical deposits in Longshoushan area,Gansu Province.Conducting in-depth research on this deposit is beneficial to guide the prospecting work in other areas within the region.This paper has combined the previous exploration data in the past years and research achievement to summarize the uranium mineralization characteristics of Jiling deposit systematically.Based on this,the geochemistry of rock and ore zone and the ore-controlling structures is analyzed to explore for the alteration mineralization mechanism and structural ore-controlling mechanism.The study result indicates that Jiling deposit is located near the contact zone controlled by Malugou fault.From the rock mass to ore body,there is a zonation phenomenon of porphyritic granite-non-mineralized sodium metasomatic rock-anomalous sodium metasomatic rock-mineralized sodium metasomatic rock-ore-bearing sodium metasomatic rock.The ore development is mainly characterized by sodium feldspathization,hematitization,carbonatization and chloritization.The mineralization process is experienced for two stages of hydrothermal alteration,namely,early-stage of magmatic hydrothermal autometasomatism and late-stage superimposed external circulating fluid mineralization enrichment alteration,with the typical alteration feature sodium of feldspathization and hematitization.In terms of spatial distribution,the ore bodies are controlled by Malugou fault and its secondary faults.Due to the complexity of Malugou fault,through the investigation of extensive deep drilling holes,it is currently considered that Malugou fault can be roughly divided into two parallel faults,F101 and F105,influenced by the residual body of Paleoproterozoic Baijiazui Formation marble.These two faults converge into a steeply dipping fault at the apex of the deep residual body.Comprehensive analysis suggests that the secondary faults of Malugou fault are ore-controlling structures.The area between the main and secondary fault structures is the most favorable zone for

关 键 词：芨岭铀矿床 钠交代 马路沟断裂 龙首山地区 

分 类 号：P619.14[天文地球—矿床学]