摘要
江西相山地区是中国重要的火山岩型铀矿床的发育地区之一,近年来在其深部发现了大量的铅锌矿脉,为进一步确定铅锌矿与铀矿床的成因,本文利用蚀变矿物进行39 Ar-40 Ar法测年及C-H-O同位素特征研究,并结合前人的研究资料,得到了矿田铀铅锌多金属矿化年龄并构建了矿田的成矿模式。铅锌矿的形成时间为137.5~138.3 Ma,铀矿床的成矿时间为(132.6±1.3)Ma、(122.8±1.1)Ma,结合流体包裹体特征,判断铀矿床具有两期成矿特点。成矿流体与成矿物质大部分来自于赋矿火山-侵入杂岩岩浆,变质水和大气水参与了成矿作用,深部(幔源)富铀流体物质的后期加入是矿田形成铅锌与铀两种不同矿化类型的重要原因。相山矿田的铀与铅锌矿化同属一个成矿系统,是矿田火山-岩浆热液成矿系统活动于不同时期、不同阶段的产物。
Xiangshan ore field, located in Jiangxi Province, is one of the most important volcanic type of uranium deposits in China. Recently, a number of deep lead-zinc orebodies have been found in the Xiangshan area. However, whether the two kinds of deposit （Pb-Zn deposit and U deposit） came from the same set of metallogenic system or had the similar ore-forming material source is still ambiguous. In this contribution, 39Ar-4~Ar dating of alteration mineraIs （sericite and hydromica）, H-O isotopic （sericite and hydromica） and C-O isotopic （calcite） studies have been carried out to determine the genesis of Pb-Zn deposit and U deposit. The metallogenic ages of Pb-Zn deposit and U mineralization were 137.5 - 138.3 Ma and 122.8 - 132.6 Ma, respectively. Stable isotopic studies show that ore-forming fluids of Pb-Zn deposit and U deposit were mainly magmatie and metamorphic water, and the atmospheric water might participate in the fluids evolution during U mineralization. Carbon was derived from the deep mantle. It is proposed that： （1） U deposit and Pb-Zn deposit were the results of activities in different times and stages of the same volcano-magmatic hydrothermal ore-forming system, and the U deposit has the characteristic of the two mineralization stages; （2） ore-forming fluids were mostly derived from ore-rich magma, and metamorphic water and atmospheric water were involved during the mineralization process; and （3） deep （mantle） uranium-rich fluid substance added in the late stage is an important reason for the formation of Pb-Zn and U deposit in different stages.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2017年第5期283-298,共16页
Earth Science Frontiers
基金
国家自然科学基金项目(41602069)
放射性地质与勘探技术国防重点学科实验室开放基金项目(RGET1402)
江西省教育厅科学技术研究项目(GJJ150554)
关键词
铀矿
铅锌矿
成矿时代
成矿模式
相山
uranium
lead-zinc
metallogenic epoch
metallogenic model
Xiangshan
