投稿时间：2012-06-30
修订日期：2012-08-30
中文摘要:松湖铁矿床位于新疆西天山阿吾拉勒成矿带中段,赋存于石炭系大哈拉军山组火山-沉积岩系中。矿体呈似层状、透镜状,主要受近EW向、NWW向高角度逆断层控制。矿石主要呈块状、条带状、团块状构造,结构主要为半自形-他形粒状;矿石矿物主要为磁铁矿,其次为赤铁矿、黄铁矿及黄铜矿,脉石矿物主要为钾长石、绿泥石、方解石、绿帘石及阳起石等。围岩蚀变发育,在垂向和水平方向上具有分带性。矿区围岩是阿吾拉勒地区早石炭世岛弧火山岩的组成部分,不同岩性具有类似的稀土元素配分模式,均为轻稀土元素富集的右倾型,发育弱的负铈异常,中到弱的负铕或正铕异常。矿石中磁铁矿的∑REE值变化于20.75×10-6~65.41×10-6,配分模式为轻稀土元素富集的右倾型,发育中到弱的负铈及负铕异常。磁铁矿与围岩的稀土元素特征表明二者具有成因联系,与岛弧火山作用有关。磁铁矿微量元素特征表明成矿物质来源于深部,磁铁矿为火山热液交代成因。结合矿床地质特征,认为松湖铁矿床为海相火山热液型矿床。
Abstract:Located in the center of the Awulale metallogenic belt of Western Tianshan, the Songhu iron deposit is hosted by Lower Carboniferous Dahalajunshan volcanic-sedimentary Formation. Ore bodies which occur in stratoid and lenticular forms are mainly controlled by the nearly EW-trending or NWW-trending thrust faults. Ore structures mainly occur in massive, striped, and agglomerated forms, whereas ore textures dominantly display the subhedral-anhedral granular form. Ore minerals are mainly magnetite, with minor hematite, pyrite and chalcopyrite, while gangue minerals are mainly potassium feldspar, chlorite, calcite, epidote and actinolite. The alteration of wall rock with zonation in vertical and horizontal directions is well developed. The wall rocks constitute a part of volcanic rocks of the Carboniferous island arc in Awulale area, having similar chondrite-normalized REE patterns and rich LREE, with weak Ce negative anomalies and moderate to weak Eu positive or negative anomalies. Magnetite contains 20.75×10-6~65.41×10-6 REE, and there exist LREE enrichment, weak Ce negative anomalies and moderate to weak Eu negative anomalies. REE characteristics of the wall rock and the magnetite imply that there is a genetic connection between them, and both of them are related to volcanism in an island arc environment. Trace elements of the magnetite show that the ore-forming material was derived from the depth and magnetite was generated by volcano-hydrothermal replacement. Combined with ore geology, the authors have drawn the conclusion that the Songhu iron deposit is a marine volcanic hydrothermal deposit rather than a volcanic sedimentary deposit as considered by previous researchers.
文章编号：
中图分类号：P618.31
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基金项目:本文受中国地质调查局地质大调查工作项目(编号:1212011085527)资助
引用文本：
王春龙,王义天,董连慧,张兵,任毅.2012.新疆西天山松湖铁矿床稀土和微量元素地球化学特征及其意义[J].矿床地质,31(5):1038~1050WANG ChunLong,WANG YiTian,DONG LianHui,ZHANG Bing,REN Yi.2012.Geochemical characteristics of rare earth and trace elements compositions of Songhu iron deposit in western Tianshan of Xinjiang and their significance[J].Mineral Deposits31(5):1038~1050
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