内蒙古自治区查汗木胡鲁石墨矿矿床成因研究

发布时间：2018-05-08 17:01

  本文选题：乌拉山岩群 + 片麻岩　； 参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：内蒙古查汗木胡鲁石墨矿位于华北地台北缘西段,因受到多期次变质作用叠加,使得变质岩广泛发育。矿区内区域变质岩最为发育,主要为中太古界乌拉山岩群的浅变质岩系,主要包括片岩、片麻岩及大理岩等。本文在充分搜集与分析前人研究结果的基础上,通过分析已有的大比例尺岩性图和地质剖面图,对该矿床的石墨矿体空间展布、岩石类型及矿物学特征做了详细的描述和研究。查汗木胡鲁石墨矿床共发现11条矿体,其中9个露头矿体,2个隐伏矿体。野外实测发现,石墨矿体赋存于乌拉山岩群的透辉斜长片麻岩和黑云斜长片麻岩中,矿体顶底板围岩主要为蛇纹石化大理岩,为一套典型的变质沉积岩组合含矿建造。并且石墨以大鳞片状分布于脉石矿物颗粒间,具有一定的层理,说明石墨矿质与地层岩石同时沉积。而该地区原始岩性组合为含炭质泥质粉砂岩、含炭质白云质灰岩、含炭质碳酸盐岩等(袁见齐等,1979)。再加上后期岩浆侵入,以及钾化、硅化等混合岩化作用,使得石墨晶体进一步增大形成了中粗粒片麻岩型石墨矿。因此,查汗木胡鲁石墨矿床具有区域变质型矿床的典型特征。通过选取无蚀变的石墨标本做了13C同位素分析,根据分析结果,利用碳同位素对比图进行解译,查汗木胡鲁石墨矿石中石墨碳同位素的数值都在-7.6‰到-9.6‰之间,主要集中分布-9‰左右,平均值为-8.72‰。这与碳酸盐、金刚石的碳同位素数值范围符合,而与生物有机物的碳同位素范围相差较大。二者处于截然不同的区间,说明查汗木胡鲁石墨矿床的碳质来源主要为无机碳。
[Abstract]:Chahanmuhulu graphite deposit in Inner Mongolia is located in the western part of the North China platform, and the metamorphic rocks are widely developed due to the superposition of multiple metamorphic processes. The regional metamorphic rocks are the most developed in the mining area, mainly composed of the shallow metamorphic rocks of the Wulashan Group of the Middle Archean, including schist, gneiss and marble. Based on the full collection and analysis of the previous research results, this paper makes a detailed description and study on the spatial distribution, rock types and mineralogical characteristics of the graphite orebody by analyzing the existing large scale lithologic maps and geological profiles. A total of 11 orebodies were found in Chahan Muhuru graphite deposit, of which 9 outcrops and 2 concealed orebodies. It is found that the graphite orebody is located in the diopside gneiss and the black cloud plagioclase gneiss of the Wulashan rock group. The surrounding rock of the top and bottom plate of the orebody is mainly serpentinized marble, which is a set of typical metamorphic sedimentary rock assemblage ore-bearing formation. Graphite distributes in the shape of large scale between gangue mineral particles and has certain stratification, which indicates that the graphite mineral and stratigraphic rocks are deposited at the same time. The primary lithologic assemblage in this area is carbonaceous argillaceous siltstone, carbonaceous dolomite limestone, carbonaceous carbonate rock and so on (Yuan Jianqi et al. Combined with the late magma intrusion and the mixed lithology such as potassium and silicification, the graphite crystal is further enlarged to form the medium coarse gneiss type graphite ore. Therefore, Chahan Muhuru graphite deposit has the typical characteristics of regional metamorphic deposit. The 13C isotopic analysis of graphite samples without alteration was carried out. According to the results of the analysis, the carbon isotopes of graphite in Cha-han Muhulu graphite ore were interpreted by using the carbon isotope comparative map. The values of graphite carbon isotopes in Cha-han Muhulu graphite ore ranged from -7.6 鈥，

本文编号：1862244