新疆西天山松湖铁矿床磁铁矿成分特征及其成因  

Magnetite Composition and Its Genetic Significance of the Songhu Iron Deposit in the Western Tianshan,Xinjiang,NW China

作　　者：朱维娜 王义天[2] 王春龙[2,3,4] 张兵[5] 张立成[1,2] 任毅[5] 肖燕红[5] 袁彦超[6] 胡相波[6] 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]中国地质科学院矿产资源研究所国土资源部成矿作用与资源评价重点实验室,北京100037 [3]中国科学院新疆生态与地理研究所新疆矿产资源研究中心,新疆乌鲁木齐830011 [4]中国科学院大学,北京100049 [5]新疆地质矿产勘查开发局第七地质大队,新疆乌苏833300 [6]中水北方勘察设计研究有限责任公司,天津300222

出　　处：《地球科学（中国地质大学学报）》2015年第10期1723-1740,共18页Earth Science-Journal of China University of Geosciences

基　　金：中国地质调查局地质大调查工作项目“新疆天山古生代构造岩浆成矿系统与勘查模型研究”(No.1212011085527)

摘　　要：松湖铁矿位于新疆阿吾拉勒成矿带中段,其成矿作用经历了2期6个阶段:硫化物-钾长石阶段、赤铁矿-方解石-绿泥石阶段、磁铁矿-绿泥石-钾长石阶段(称为早阶段铁矿化)、磁铁矿-硫化物阶段(称为晚阶段铁矿化)、方解石-黄铜矿阶段及表生期.为了分析其成分特征及其成因,使用磁铁矿电子探针分析,结果显示:早阶段磁铁矿FeOT含量高,TiO2、Al2O3、MgO、MnO等含量均较低,与接触交代矿床成分特征相似,加之SiO2含量较高,暗示其形成与酸性岩浆热液密切相关;晚阶段为主成矿阶段,广泛作用于早阶段矿石之上,磁铁矿FeOT含量相对较低,TiO2、MnO、V2O3、MgO、Al2O3等含量高于早阶段磁铁矿,显示为热液成因.综合矿床地质特征,认为晚阶段磁铁矿形成于岩浆活动晚期或间歇期,含矿热液中有海水的加入.The Songhu iron deposit located in the middle Awulale Fe-Cu metallogenic belt of Western Tianshan. The minraliza- tion of Songhu iron deposit included two metallogenic periods which could be further subdivided into six metallogenic stages, i. e. , sulfide-k-feldspar stage, hematite-calcite-chlorite stage, magnetite-chlorite-k-feldspar stage（early stage of magnetite）, magnetite-sulfide stage（late stage of magnetite）, calcite～ehalcopyrite stage and supergene period. In order to analyze the charac- teristics and causes of its components, Electron microprobe analyses show that the magnetites formed in early stage were rieh in FeOT and poor in TiO2, Al2O3, MgO, MnO, which are similar to those of contact-metasomatic deposits. High content of SiOz suggests that the formation of early magnetite was associated with acidic magmatic hydrothermat system. late magnetite stage was the main minralization stage which was widely superimposed on ores formed during the early stage. Magnetites have lower content of FeOT and higher content of TiO2, MnO, V2 O3, MgO, Al2O3. Both ternary plot of TiOa-AL2O3-MgO and Ca＋Al＋Mn vs. Ti＋V discriminant diagram suggest that late magnetites were the product of hydrothermal mineralization. Considering the geological features of ore deposit, we infer that late magnetites are formed in the late magmatic activity or peri od of inactivity with the participation of sea water.

关 键 词：磁铁矿 电子探针 成分特征 松湖铁矿 阿吾拉勒成矿带 西天山 

分 类 号：P318.4[天文地球—固体地球物理学]