吉林省白山市板石沟铁矿构造变形与成矿预测

发布时间：2018-06-26 03:20

本文选题：板石沟 + 鞍山式铁矿　；参考：《吉林大学》2015年硕士论文

【摘要】：板石沟铁矿位于华北板块北缘东段，龙岗复式背斜南翼是中国典型的太古宙变质杂岩出露区，遭受了强烈的变质变形作用。板石沟地区主体构造为一倒转复式向斜构造。区内矿产资源丰富，铁矿主要为鞍山式铁矿，大中型铁矿主要分布在太古宙杨家店组中。板石沟地区是鞍山式铁矿产出的有利地区，在板石沟开展铁矿成矿预测研究，对于指导板石沟地区铁矿勘查部署具有一定的意义。本文通过野外地质踏勘、室内分析研究，对本区铁矿石及围岩地球化学特征、年代学特征及其构造控矿特征进行了深入的研究，得出的主要认识如下：板石沟铁矿矿石类型主要以磁铁石英岩为主，其次为角闪磁铁石英岩，铁矿围岩主要为中粗粒斜长角闪岩、角闪片岩和黑云斜长片麻岩。磁铁石英岩与斜长角闪岩类岩石紧密共生，呈厚度不等的透镜状、条带状断续分布在斜长角闪类岩石中。磁铁矿矿石硅和铁的氧化物含量平均达到92.97%，其稀土元素配分曲线与鞍山-本溪磁铁石英岩的基本一致，呈现出明显正Eu和Y异常，是经过海水和热液流体混合的化学沉积物。板石沟铁矿赋存于太古宙杨家店组中，严格受层位控制，，该组岩石原岩建造属中酸性-基性火山沉积建造，铁矿石为含铁较高的磁铁石英岩，具有变质岩岩控特征，其强烈的高场强元素Nb、Zr、Hf和Ti负异常，也说明其成矿作用与火山作用有关。与板石沟铁矿石密切伴生的斜长角闪岩的锆石LA-ICP-MS U-Pb加权平均年龄为2548±11Ma，代表了板石沟铁矿的形成时代，这与辽东鞍山铁矿形成时代一致。板石沟铁矿共5个采矿区，16个矿组，南部16、17、19矿组矿体向北倾，北部7-8、14-15和6等矿组矿体向南倾，这些矿组形成了轴向北西的复式向形构造，其转折端在木通沟地区。8矿组矿体总体为向南西西倾伏的复式“向斜”褶皱，由一系列相间排列的次一级背斜和向斜构造组成，木通沟矿体总体为北东向展布，向南东倾，倾角在10°~45°之间，该地区区含矿层有两层，一层矿体较薄，另一层矿体发生褶皱变形，造成局部有多层矿体的假象。板石沟地区铁矿及其围岩经历了三期变质变形改造：第一期是早期顺层伸展滑移变形作用，这一期变形使木通沟矿体形成了较宽缓的顺层滑移褶皱；第二期是以第一期褶皱构造面为变形面，受到北北西-南南东向挤压作用，形成了北东东向较为宽厚的板石沟复式向斜褶皱-板石沟主体构造形态；第三期是在第二期主构造轮廓上，局部受到北西-南东向挤压作用，使第二期构造面局部变形，将矿体局部改造为近南北向。板石沟铁矿主要赋存于褶皱构造的核部，核部矿体厚度较大，翼部较薄或没有矿体，根据板石沟地区构造变形特征和航磁异常特征，选定了8矿组断裂下部、木通沟北东侧深部、17矿组南部和北东部区域作为本区矿产勘查的重要远景区。今后的找矿方向：褶皱变形构造的核部，航磁异常与向形构造相吻合的低缓磁异常区找盲矿体。
[Abstract]:It is located in the eastern part of the northern margin of the North China plate. The southern wing of the Longgang compound anticline is a typical Archean metamorphic complex Iwade area in China, which has suffered a strong metamorphic and deformed effect. The main structure of the area is a reverse complex syncline structure. The mineral resources in the area are rich in mineral resources, the main iron ore is Anshan type iron ore, and the large and medium size iron ore distribution is mainly distributed. In the Archean Yangjia group, the area of the Sinkou area is a favorable area for the production of Anshan type iron ore, and it is of great significance to carry out the study on the metallogenic prognosis of the iron ore in the slate gully, which is of certain significance for guiding the exploration and deployment of the iron ore in the area of the plate.
In this paper, the geochemical characteristics of iron ore and surrounding rock in this area, the characteristics of the geochronology and the characteristics of its ore control are deeply studied through the field geological survey and the indoor analysis. The main understanding is as follows:
The main ore types of the banshiggou iron ore are mainly magnetite quartzite, followed by hornblende magnetite quartzite. The iron ore is mainly medium coarse amphibolite, hornblende and black cloud slanted gneiss. Magnetite quartzite is closely associated with diagonal amphibolite, with a lens like thickness of different thickness. The strip is distributed intermittently in the diagonal amphibolite. In the stone, the content of silicon and iron oxide in magnetite ore is up to 92.97%, and the distribution curve of rare earth elements is basically the same as that of Anshan Benxi magnetite quartzite, showing obvious positive Eu and Y anomalies, which are chemical sediments mixed by sea water and hydrothermal fluids.
The bsigou iron ore deposit occurs in the Archean Yangjia group and is strictly controlled by the layers. The rock formation of the rock formation belongs to the medium acidic basic volcanic deposit, and the iron ore is a high iron bearing magnetite quartzite, which has the characteristics of metamorphic rock control, and its strong high field and strong elements Nb, Zr, Hf and Ti are negative. It also indicates that the mineralization is related to the volcanism.
The zircon LA-ICP-MS U-Pb weighted average age of the diagonal amphibolite, which is closely associated with the beitangou iron ore, is 2548 + 11Ma, representing the age of the formation of the beitangou iron ore, which is in accordance with the age of the formation of Anshan iron ore in Liaodong.
The bshitu iron mine has 5 mining areas, 16 mine groups, the southern 16,17,19 ore body is tilting northward, and the northern 7-8,14-15 and 6 ore bodies are inclined to the south. These ore formations form the compound axis of the axis to the North West, and the turning end is in the.8 mine of the Mu Tong gully area as a general compound "syncline" fold to the South West West. The second grade anticline and syncline structure of the column is composed of the north east direction and the South East, and the dip angle is between 10 degrees ~45 degrees. The area contains two layers, the one layer is thinner and the other ore body folds and deformation, resulting in the false image of the local multi layer orebody.
The iron ore and its surrounding rock in the area of the satiigou area have undergone three stages of metamorphism and deformation: the first stage was the early bedding extension and slip deformation, which resulted in the formation of a wider and slower bedding slip folds in the maitaitu orebody, and the second stage was the first stage of the fold tectonic surface as the deformation surface, and the North North West South to South East compression was formed, and the North was formed north. East east to the more broad swell trench complex syncline fold - Slate main structure form; the third phase is on the second phase of the main tectonic outline, locally subjected to the north-west - southward extrusion, the second phase of the tectonic surface, local transformation of the ore body to the near North and south direction.
The iron ore body of the plate is mainly located in the nuclear part of the fold structure, the thickness of the core ore body is large, the wing is thin or there is no ore body. According to the characteristics of structural deformation and aeromagnetic anomaly in the area of the area of the plate, the lower part of the 8 mine is selected, the deep part of the north east side of the komitaitu, the southern part of the 17 ore group and the North East region are the important prospective areas of the mineral exploration in this area.
In the future, the direction of prospecting is: the core part of the folded deformation structure, the aeromagnetic anomaly and the low magnetic anomaly area which are consistent with the oriented structure.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.31

【参考文献】