华南地质2025，Vol.41Issue(4)：804-819,16.DOI:10.3969/j.issn.2097-0013.2025.04.010
桂北摩天岭达亮铀矿床绿泥石特征及其对铀成矿作用的指示
The Genesis of Chlorite in Daliang Uranium Deposit in Motianling,Northern Guangxi and Its indication of Uranium Mineralization
摘要
Abstract
The Daliang uranium deposit is located in the southwestern segment of the Jiangnan Orogenic Belt and constitutes a significant uranium resource in South China.Chlorite,a widespread hydrothermal alteration mineral in the deposit,serves as a key prospecting indicator for uranium mineralization.Its geochemical characteristics provide critical constraints on the evolution of the ore-forming fluids and the genesis of the deposit.Based on petrographic and electron probe microanalysis(EPMA),this study classifies the chlorite types in the Daliang deposit,estimates their formation physicochemical conditions,and discusses their relationship with uranium mineralization.The results show that chlorite in the deposit can be divided into four types:feldspar-altered chlorite(Chl1),biotite-altered chlorite(Chl2),fracture-filling chlorite(Chl3),and uranium-associated chlorite(Chl4).These chlorite types exhibit distinct compositional differences:Chl1 is dominated by chamosite,while Chl2,Chl3,Chl4 are all brunsvigite,with Chl2 containing higher Mg than Chl1.Physicochemical calculations indicate that the four chlorite types formed at temperatures of 208-252℃,with oxygen fugacity ranging from-50.63 to-41.20 and sulfur fugacity from-5.52 to 1.43.These conditions suggest formation in a moderate-to-low temperature,low-oxygen,and low-sulfur fugacity reducing hydrothermal environment,which is favorable for uranium unloading,precipitation,and mineralization.Chloritization contributed to uranium mineralization through two main mechanisms:first,by altering the physiochemical properties of the wall rock and simultaneously releasing uranium from uranium-rich accessory minerals in biotite,thereby supplying ore-forming materials;second,by precipitating Fe-and Mg-rich chlorite from the fluid,which disturbed fluid chemical equilibrium,destabilized uranium complexes and ultimately promoted uranium enrichment and precipitation from the hydrothermal fluid.关键词
绿泥石/电子探针/成矿机制/达亮铀矿床/摩天岭Key words
chlorite/EMPA/metallogenic mechanism/Daliang uranium deposit/Motianling分类
天文与地球科学引用本文复制引用
史竟存,朱坤贺,王凯兴,叶凡琛,周心怡..桂北摩天岭达亮铀矿床绿泥石特征及其对铀成矿作用的指示[J].华南地质,2025,41(4):804-819,16.基金项目
中国铀业有限公司-东华理工大学核资源与环境国家重点实验室联合创新基金项目(编号:2023NRE-LH-01)、中国核工业地质局高校科研攻关项目(编号:201619)和东华理工大学研究生创新基金项目(编号:DHYC-202460) （编号:2023NRE-LH-01）
