山西临汾西里北铁矿矿床地质特征及找矿前景

Geological Characteristics and Prospecting Potential of Xilibei Iron Deposit in Linfen City,Shanxi Province

结合山西西里北铁矿地质工作成果,分析了矿区及矿床地质特征,并就矿区找矿前景进行了讨论。研究表明:(1)该矿床产于燕山期二峰山系列辉石二长闪长玢岩与中奥陶统上马家沟组一至三段白云质灰岩、花斑状灰岩等围岩的接触带附近,矿体与围岩接触带的形态、规模以及复杂程度为重要的控矿因素,同生背斜褶皱、层间滑脱面为矿体赋存的有利部位,岩体钾长石化、矽卡岩化为找矿的直接标志;(2)西里北铁矿为一接触交代型磁铁矿床,矿体一般赋存于岩体与灰岩的接触带上,矿体的成矿母岩为燕山期二长闪长玢岩,围岩为奥陶系灰岩,燕山期二长闪长玢岩侵入于奥陶系灰岩中,在高温热液蚀变的作用下,铁质发生富集,磁铁矿被大量析出沉淀,从而形成了磁铁矿床;(3)矿区已经揭露的矿体南东部、北东部,5#线北西部以及4#~6#线区域,矿区东部十村山附近,距离大王磁异常5~15 km的东亢磁异常、南孙磁异常、东张磁异常、张綦磁异常以及宋村磁异常的找矿前景较好。

Based on the geological working results of Xilibei Iron Deposit in Shanxi Province,the geological characteristics of the mining area and deposit is analyzed,and the deposit genesis and prospecting potential of the mining area are also discussed in depth. The study results show that：（1）the deposit is distributed at the nearby of the contact zone of pyroxene diorite porphyrite of Yanshanian Eifeng Mountain Series and dolomitic limestone and variegated limestone from section one to section three section of Middle Ordovician Shangmajiagou Formation,the shape,scale and complexity of the contact zone of ore-body and its surrounding rock are the important ore-controlling factors,the advantageous position of the ore-bodies are mainly for synclinal anticlinal fold and interlayer slip surface,potassium feldspathization and skarnization of the rock mass can be taken as the direct prospecting indicators;（2）genesis of Xilibei Iron Deposit is belongs to contact metasomatism type magnetite deposit,ore-bodies are usually distributed on the contact zone of the rock mass and limestone,the metallogenic parent rock is mainly for Yanshanian diorite porphyrite,surrounding rock of the ore-bodies is Ordovician limestone,Yanshanian diorite porphyrite intrudes into Ordovician limestone,under the action of high temperature hydrothermal alteration,the phenomenon of iron enrichment is existed,the magnetite is precipitated out in large quantities and precipitated,therefore,the magnetite deposit is formed;（3）prospecting potential of the southeast,northeast of the mining area,4#~ 6#line region in the northwest of 5#line,nearby of Shicun Mountain in the east of mining area,the magnetic anomalies such as Donghang,Nansun,Dongzhang,Zhangqi,Songcun,etc. that are 5~ 15 km away from Dawang magnetic anomaly are good.