摘要
根据矿物组合及磁铁矿结晶形态特征,栖霞山铅锌多金属矿床中含磁铁矿的岩矿石可划分为铅锌硫铁矿石、铅锌铁矿石和闪锌矿化磁铁矿化灰岩。3种类型的磁铁矿单矿物稀土元素配分分析结果显示其特征相同,稀土总量较低,平均值=3.31 g/t;Eu负异常明显,δEu平均值=0.23。总体特征为轻稀土相对亏损、重稀土相对富集,配分呈平缓左倾型。与铅锌矿石、围岩及宁镇地区典型中酸性岩体对比,认为成矿物质来源于深部隐伏中酸性岩体,其特征与宁镇地区已知的燕山期中酸性侵入体有所不同。磁铁矿单矿物Eu负异常明显,说明磁铁矿成矿阶段成矿溶液为相对氧化的条件。通过Ce/Yb-Eu/Yb变异图的分析,推测隐伏岩体具有混合作用的特点。
Based on the mineral association and crystal morphology of magnetite,it is found that there are 3 representative rocks or ore types with magnetite in the Qixiashan Pb-Zn polymetallic deposit:Pb-Zn-S-mFe ore、Pb-Zn-mFe ore and Zn-mFe mineralized limestone.Analysis of REE assemblage in 3 types of magnetite monominerals shows consistent characteristics of REEs.The total amount of rare earth elements is relatively low,averaging 3.31 g/t.The negative anomaly of Eu is obvious,and the average value ofδEu is 0.23.It is relatively deficient in LREE and relatively enriched in HREE,and its distribution is gently left leaning.Compared with lead-zinc ores,surrounding rocks and typical intermediate-acid intrusions in Ningzhen area,it is believed that the ore-forming materials originated from deep concealed intermediate-acid rocks,which were different from the known Yanshanian intermediate-acid intrusions in Ningzhen area.The negative anomaly of Eu in magnetite monominerals clearly indicates that the ore-forming solution of magnetite was in relative oxidation.With the analysis of Ce/Yb-Eu/Yb variation map,it is inferred that the concealed intrusions are featured with migmatization.
作者
景山
楼锦花
魏新良
金鑫
Jing Shan;Lou Jinhua;Wei Xinliang;Jin Xin(East China Mineral Exploration and Development Bureau,Nanjing 210007,Jiangsu,China)
出处
《地质学刊》
CAS
2020年第1期85-92,共8页
Journal of Geology
基金
江苏省第五期“333工程”培养资金资助项目(2017年度)“南京栖霞山铅锌多金属矿床磁铁矿标型特征及矿床成因研究”。
关键词
稀土元素
磁铁矿
单矿物
铅锌矿
南京栖霞山
rare earth element
magnetite
monomineral
lead-zinc deposit
Qixiashan
Nanjing
Jiangsu
