内蒙古乌力吉敖包萤石矿成矿地质条件与成矿预测

发布时间：2018-05-07 08:17

  本文选题：萤石矿床地质特征 + 物探与化探　； 参考：《成都理工大学》2017年硕士论文

【摘要】：内蒙古乌力吉敖包萤石研究区地处内蒙吉林成矿带,位于西伯利亚板块和华北板块碰撞缝合处,曾经历多期构造运动及岩浆旋回。区域上,岩浆岩分布面积广,曾发生活跃的构造运动,这为形成萤石矿床提供了良好条件。研究区第四系覆盖严重,想进一步探明地下萤石矿床分布情况,则必须利用多种勘探技术的探测与实地探槽(钻探)工程的验证。通过对前人资料的整理、研究区的实地踏勘与采样分析,总结出了研究区萤石矿床地质特征、围岩蚀变、矿石特征以及初步划分了成矿期次。该区萤石矿属于浅成低温热液矿床,矿体以脉状为主,少量为透镜状;矿体垂向上呈规律变化,即硅质顶壳、矿体和凝灰岩。由于受火山岩的影响,矿体边部围岩依次从内外往外出现了硅化、绢云母化;在垂向上依次从上往下出现绢云母化、硅化、高岭石化、萤石矿化、碳酸盐化及黄铁矿化。研究区矿石为单一萤石,主要为角砾状构造和块状构造,以自形粒状结构和自形—半自形粒状结构为主。根据矿石的穿插关系初步划分为四个成矿阶段:黄铁阶段、萤石—石英阶段、石英—萤石阶段和碳酸盐—萤石阶段,其中以萤石—石英阶段和石英—萤石阶段为萤石主要形成期。经过相关资料的查阅与实验室研究,总结了研究区成矿地质条件。燕山中晚期,研究区受到NE向查干敖包—五叉沟深断裂(F7)影响,并经过多期构造改造,研究区形成众多NS向的次级构造,这为成矿提供容矿构造、导矿构造和配矿构造;伴随岩浆的活动,白音高老组(K1b)凝灰岩为成矿提供必要的温度与成矿物质,而经过实验室包裹体研究测温压表明,该萤石矿床形成温度约108~340℃,成矿平均深度为390m。本文通过地质学、地球物理学与地球化学技术方法有机结合,并采用甚低频电磁法与X荧光仪测量方法,测量出了研究区的异常区域,并进一步对研究区内具有成矿潜力的区域进行圈定。依据以上方法分析,该区圈定了4个成矿预测靶区。1号成矿远景区划分依据:地处有绢云母蚀变的正地貌,甚低频F值异常图中正高异常明显,Ca异常图中Ca高异常特别明显,实地采取地表探槽验证,划分为B类靶区;2号成矿远景区划分依据:处于正地貌,附近出露小面积岩石并伴有萤石矿化,甚低频F值异常图出现“双峰”正高异常,Ca异常图中Ca出现高异常,平洞勘探发现萤石矿床点,划分为A类靶区;3号成矿远景区划分依据:地貌上处于山腰,甚低频F值异常图出现正高异常,Ca异常图出现高异常,表明该区具有较高的勘探潜力,划分为C类靶区;4号成矿远景区划分依据:处于出现少量萤石矿化的正地貌,在甚低频F值异常图局部出现“双峰”异常,并得到了地表探槽的验证,划分为B类靶区。
[Abstract]:The study area of Aobao fluorite in Inner Mongolia is located in the Jilin metallogenic belt of Inner Mongolia, located at the collision and suture of the Siberian plate and the North China plate, and has experienced multiple tectonic movements and magmatic cycles. In the region, magmatic rocks are widely distributed and active tectonic movements have taken place, which provide favorable conditions for the formation of fluorite deposits. The Quaternary system covers heavily in the study area. In order to further investigate the distribution of underground fluorite deposits, it is necessary to make use of various exploration techniques and verification of field exploration trough (drilling) projects. The geological characteristics of fluorite deposits, wall rock alteration, ore characteristics and metallogenic stages of fluorite deposits in the study area are summarized through the collation of previous data, field exploration and sampling analysis in the study area. The fluorite deposit in this area belongs to the epithermal hydrothermal deposit, the orebody is mainly vein-like and a few is lenticular, and the orebody changes in vertical direction, I. E. siliceous top crust, orebody and tuff. Due to the influence of volcanic rock, the surrounding rock of the ore body appears silicification and sericite from inside and outside, sericite from top to bottom, kaolinization, fluorite mineralization, carbonization and pyrite from vertical to upward. The ore in the study area is a single fluorite, mainly a breccia structure and a block structure. According to the intercalation relationship of ore, it can be divided into four metallogenic stages: Huang Tie stage, fluorite-quartz stage, quartz-fluorite stage and carbonate fluorite stage. The fluorite-quartz stage and quartz-fluorite stage are the main fluorite forming stages. The metallogenic geological conditions of the study area are summarized through the reference of relevant data and laboratory research. In the middle and late Yanshan period, the study area was influenced by the NE direction Chagan Aoba-Wujiagou deep fault (F7), and through the multi-stage structural transformation, many NS secondary structures were formed in the study area, which provided the ore-bearing structure, the ore-conducting structure and the ore-blending structure for metallogenesis. Accompanied by magmatic activity, tuff provides the necessary temperature and ore-forming material for mineralization, and the temperature and pressure measurements of inclusions show that the formation temperature of the fluorite deposit is about 108 ~ 340 鈩，

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