摘要
长山铅锌多金属矿床位于长江中下游成矿带宣城矿集区东北部,文章在对该矿床开展详细的地质调查和岩相学研究基础上,对代表性矿化蚀变矿物(石英、方解石)开展了流体包裹体测温、激光拉曼光谱和氢、氧、碳稳定同位素分析。长山铅锌多金属矿床矿化蚀变组合从早到晚可以分为矽卡岩-氧化物阶段、早硫化物阶段和晚硫化物阶段。矿物流体包裹体温度和盐度测算显示,长山矿床的成矿流体温度和盐度从矽卡岩-氧化物阶段(315~382℃,w(NaCl)_(eq)为14.04%~16.24%)→早硫化物阶段(220~347℃,w(NaCl)_(eq)为4.49%~15.86%)→晚硫化物阶段(163~306℃,w(NaCl)_(eq)为1.40%~11.10%)逐渐降低。石英和闪锌矿中包裹体的δD和δ^(18)O值分别为-89.5‰~-67.8‰和-3.2‰~7.62‰,方解石中δ^(13)C和δ^(18)O值分别是-6.8‰~-1‰和10.6‰~17.1‰,同位素特征指示长山矿床的成矿流体为岩浆水与海相碳酸盐中富含有机质流体混合,从早硫化物阶段到晚硫化物阶段,成矿流体中岩浆水比例逐渐降低。长山铅锌多金属矿床矿石矿物的沉淀分别受降温和沸腾作用(早硫化物阶段)、降温和外来流体混合作用(晚硫化物阶段)的制约。区域对比显示,宣城矿集区具有矽卡岩型铅锌多金属矿床的找矿潜力。
The Changshan Pb-Zn polymetallic deposit is located in the northeast sector of the Xuancheng ore district,the Middle-Lower Yangtze River metallogenic belt(MLYB).Based on detailed geological investigations and petrographic studies of the deposit,fluid inclusion temperature measurements,Laser Raman spectroscopy and H-OC stable isotopes analysis were carried out on representative alteration minerals(quartz and calcite)related to mineralization.The mineral assemblage of the Changshan Pb-Zn polymetallic deposit can be subdivided from early to late period into skarn-oxide stage,early sulfide stage and late sulfide stage.The measurements of temperature and salinity of fluid inclusions in minerals show that the temperature and salinity of ore-forming fluid in Changshan deposit gradually decrease from skarn-oxide stage(315~382℃,w(NaCl)_(eq)=14.04%~16.24%)→early sulfide stage(220~347℃,w(NaCl)_(eq)=4.49%~15.86%)→late sulfide stage(163~306℃,w(NaCl)_(eq)=1.40%~11.10%).TheδD andδ^(18)O values of fluid inclusions in quartz and sphalerite range from-89.5‰to-67.8‰and-3.2‰to 7.62‰,respectively.Theδ^(13)C andδ^(18)O values of calcite range from-6.8‰to-1.0‰and 10.6‰to 17.1‰,respectively.The isotope characteristics indicate that the ore-forming fluid of the Changshan Pb-Zn polymetallic deposit is characterized by mixing of magmatic water and organic-rich fluid from marine carbonate.From the early sulfide stage to the late sulfide stage,the ore-forming fluid exhibit decreasing magmatic water ratios.The precipitation of ore minerals in Changshan Pb-Zn polymetallic deposit is constrained by cooling and boiling(early sulfide stage),cooling and mixing of external fluids(late sulfide stage).Regional comparison shows that the Xuancheng ore district has great potential for exploration of skarn type Pb-Zn polymetallic deposits.
作者
王静
张达玉
黄家龙
孟翔
张飞
侯舒雅
易洪
WHITE Noel Clarence
WANG Jing;ZHANG DaYu;HUANG JiaLong;MENG Xiang;ZHANG Fei;HOU ShuYa;YI Hong;WHITE Noel Clarence(School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,Anhui,China;East-China Metallurgical Institute of Geology and Exploration,Hefei 230088,Anhui,China;No.812 Geological Team of East-China Metallurgical Bureau of Geology and Exploration,Tongling 244008,Anhui,China)
出处
《矿床地质》
CAS
CSCD
北大核心
2023年第4期791-810,共20页
Mineral Deposits
基金
国家自然科学基金项目(编号:41972076)
安徽省自然资源厅科技项目(编号:2020-K-11)
安徽省公益性地质工作项目(编号:2021-g-2-11)联合资助。
