贵州省大方平寨地区铝土矿地质特征及成因探讨

发布时间：2018-09-04 12:19

【摘要】：贵州是我国铝土矿资源储量大省,同时铝土矿也是贵州省的优势矿种之一,资源丰富、矿石质量好、分布广泛、矿床规模大,其勘探工作始于20世纪40年代,历经70多年的勘探与综合研究工作,截止2014年12月共探获资源量约12.9亿吨,居全国第二位(刘幼平,等,2016),然而受限制于环境因素;铝土矿开发、开采技术偏低因素;外部地理条件不佳等因素,贵州地区对于铝土矿的开采均处于地层浅表地区或者露天区域,并且所开采的铝土矿也是品位达到优良级别矿体,对其研究多属局部区域、相对零散的研究。然而伴随现代经济发展的是不断严峻的资源消耗需求,对于铝矿产资源的需求同样也变的尤为重要,对新的铝土矿资源的发现也变得十分紧迫,同时,这也为铝土矿资源的勘查开发带来了巨大的动力。本次研究区域平寨地区的铝土矿临近息烽、修文等铝土矿床,拥有与这些铝土矿床相类似的区域地质特征和相近的铝土矿沉积地质条件。尽管如此,区域相互领近,但是对于平寨地区的矿产资源勘查工作开展的非常有限,程度也不足,对铝土矿的调查也远远不如相邻地区铝土矿。通过笔者这次在平寨地区地质调查,对区域内赋存的铝土矿体进行调查研究工作,在对区域地质进行调查研究同时对矿体进行详细勘查,以区域地质背景为前提,揭示矿体的地质背景,查明铝土矿矿体的相关特征,并与本区相邻区域已发现或已开采的铝土矿进行对比,横向比对铝土矿形成所需地质背景特征与矿体形成条件、制约因素等,同时也受前人所开展的铝矿产勘探研究成果的启示,对平寨地区铝土矿资源的形成原因进行了探讨,期望对本研究区的铝矿产资源未来勘查、开发工作提供参考。本次研究的地区——平寨穹窿行政区划处于贵州省西北的大方县、黔西县和金沙县这三个县区交界位置,大地构造位置处于华南板块内部的上扬子区块内,穹窿本身也处于“黔中隆起”区北端,靠近北面的坳陷区域,属于大方——黔西的北东方向的弱变形区块。“黔中隆起”内部构造运动特点明显:具有多期次性、多旋回的特征,区域内部大部分区域属于基底加盖层两部形成。这对于沉积型矿产的形成提供母岩基质、穹窿构造的普遍发育也为不同沉积矿产形成提供空间。所以“黔中隆起”区域内矿产资源丰富,也有很多研究者对其进行过研究调查,但对本次研究区域内部铝土矿的研究鲜少见之。笔者通过调查研究了解到:本区铝土矿体主体产于中二叠统梁山组地层中,平寨穹窿是矿体的主体构造,矿体呈层状、似层状赋存于含矿岩系的底部,矿石矿物成份以一水硬铝石为主,矿石化学成份主要有A12O3、SiO2、TiO2等为主,矿石的结构以豆状、鲕状、泥晶、粉晶等结构为主,而矿石的构造特征则为致密块状构造和半土状构造以及块状构造,自然状态下的矿石有半土状、豆鲕状铝土矿、致密状铝土矿等。矿体为沉积型矿体,由母岩风化后经一系列物理化学作用将富铝碎屑物经过后期沉积、变质最后富集。而矿体受古气候、古地理环境、构造演化、地层特征等多种因素控制。通过研究发现本区铝土矿体基本符合Ⅲ级硬质耐火粘土的矿石质量要求,矿体厚度也大于开采厚度;不足之处在于CaO略高,超过0.8%的一般要求,仅可作为普通耐火粘土资源加以利用。
[Abstract]:Guizhou is a province with large bauxite reserves in China. At the same time, bauxite is one of the dominant minerals in Guizhou Province. It has abundant resources, good ore quality, wide distribution and large-scale deposits. Its exploration began in the 1940s. After more than 70 years of exploration and comprehensive research work, about 1.29 billion tons of bauxite resources have been discovered by December 2014, ranking the first in China. Two (Liu Youping, et al., 2016), however, are limited by environmental factors; bauxite development, mining technology is low; external geographical conditions are not good and other factors, the mining of bauxite in Guizhou area are in shallow strata or open-pit areas, and the mining of bauxite is also good grade ore bodies, its research is mostly belong to However, with the development of modern economy, the demand of resource consumption is becoming more and more severe. The discovery of new bauxite resources is becoming more and more urgent. At the same time, it also brings great impetus to the exploration and development of bauxite resources. The bauxite deposits in Pingzhai area are close to Xifeng, Xiuwen and other bauxite deposits. They have similar regional geological characteristics and similar sedimentary geological conditions. However, the areas are close to each other, but the exploration work of mineral resources in Pingzhai area is very limited and insufficient. Through the author's geological survey in Pingzhai area, the bauxite ore bodies in the region are investigated and studied, and the ore bodies are also explored in detail. The geological background of the ore bodies is revealed and the bauxite ore deposits are identified on the premise of the regional geological background. Compared with the bauxite discovered or mined in the adjacent area, the geological background characteristics needed for the formation of bauxite, the forming conditions and restricting factors of bauxite are compared horizontally, and the formation reasons of bauxite resources in Pingzhai area are discussed based on the results of previous research on bauxite exploration. The administrative division of Pingzhai dome is located at the junction of Dafang County in Northwest Guizhou Province, Qianxi County and Jinsha County, and the geotectonic position is in the upper Yangtze block within the South China plate, and the dome itself is also located. Located in the northern end of the "Central Guizhou Uplift" area, the depression area near the North belongs to the weak NE-trending deformation block of Dafang-western Guizhou. The structural movement of the "Central Guizhou Uplift" is characterized by multi-period and multi-cycle, and most of the areas in the region are formed by two parts of the basement and caprock. This is the shape of sedimentary mineral resources. Therefore, there are abundant mineral resources in the "central Guizhou uplift" area, and many researchers have studied and investigated it. But the study of bauxite in this study area is rare. The author has found that: the area of aluminium is rich in mineral resources. The main body of the earth ore body occurs in the Liangshan Formation strata of the Middle Permian. The Pingzhai dome is the main structure of the ore body. The ore body is stratified and occurs at the bottom of the ore-bearing rock series. The mineral composition of the ore is mainly diaspore. The chemical composition of the ore is mainly A12O3, SiO2, TiO2 and so on. The structure of the ore is beady, oolitic, mud crystal and powder crystal. The main structural features of the ore are dense massive structure, semi-soil structure and massive structure. The natural state of the ore is semi-soil-like, oolitic bauxite, dense bauxite and so on. The ore body is sedimentary type, weathered by the parent rock after a series of physical and chemical processes will be rich in aluminium clastic deposits, metamorphism and finally enrichment. The ore body is controlled by many factors such as palaeoclimate, palaeogeographic environment, tectonic evolution, stratigraphic characteristics, etc. It is found that the bauxite ore body in this area basically meets the ore quality requirements of grade III hard refractory clay, and the thickness of the ore body is also greater than the mining thickness. The source is utilized.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.45

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