华南地质2025，Vol.41Issue(4)：787-803,17.DOI:10.3969/j.issn.2097-0013.2025.04.009
相山铀矿田济河口矿床热液蚀变与元素迁移特征研究
Study on Hydrothermal Alteration and Element Migration Characteristics of the Jihekou Deposit in the Xiangshan Uranium Ore Field
摘要
Abstract
The Jihekou uranium deposit,a recent discovery in the western Xiangshan uranium ore field,exhibits a significant correlation between the distribution of uranium mineralization and the intensity and types of wall-rock alteration.Focusing on altered rocks from this deposit,this paper systematically investigates the characteristics of alteration zoning,hydrothermal alteration processes,and patterns of element migration.Petrographic analysis indicate that the alteration zones of the Jihekou deposit can be divided from the outer to inner as fresh rhyodacite,an altered transition zone,and a mineralized central zone.Intense hydrothermal alteration is developed in the ore district,with fluoritization,carbonatization,and pyritization closely associated with uranium mineralization.Mass balance calculations reveal that from the fresh rhyodacite to the mineralized central zone,Na2O,CaO,P2O5,U,Th,Eu,and heavy rare earth elements(HREE)are gradually enriched with CaO,P2O5,U,and Th exhibiting significant introduction in the mineralized central zone.In contrast,SiO2,Fe2O3,Rb,Nb,Hf,and light rare earth elements(LREE)are variably depleted.Both the altered transition zone and the mineralized central zone are characterized by significant introduction of Na2O and notable removal of K2O,reflecting the widespread effects of albitization throughout the mineralized alteration zone.Geochemical analysis reveals markedly elevated δEu values in the altered transition zone and mineralized central zone,indicating relatively high oxygen fugacity in the ore-forming fluid,potentially linked to meteoric water.The enrichment of FeO and strong depletion of Fe2O3 in the mineralized central zone suggest a reducing environment conducive to the precipitation of pitchblende.Pronounced HREE enrichment and slight LREE depletion in the altered transition zone and mineralized central zone indicate that the ore-forming fluids were rich in components such as P,F-,Cl-,and CO32-,leading to the formation of gangue minerals closely associated with pitchblende,including fluorite,calcite,and apatite.Furthermore,uranyl phosphate complexes may have served as an important transport forms for uranium in the ore-forming fluids of the Jihekou deposit.关键词
济河口铀矿床/热液蚀变/元素迁移/质量平衡/成因Key words
Jihekou uranium deposit/hydrothermal alteration/element migration/mass balance/genesis分类
天文与地球科学引用本文复制引用
何世伟..相山铀矿田济河口矿床热液蚀变与元素迁移特征研究[J].华南地质,2025,41(4):787-803,17.基金项目
中国核工业地质局项目(编号:202229-2) （编号:202229-2）
