贵州道真县新民铝土矿床地质地球化学特征研究

发布时间：2018-04-20 12:39

本文选题：贵州道真新民 + 铝土矿　；参考：《昆明理工大学》2015年硕士论文

【摘要】：铝土矿是贵州主要矿种之一,集中分布在黔中—黔北地区。近年来实施整装勘查黔北务正道地区铝土矿找矿取得重大突破,相继探明中大型、超大型铝土矿矿床10余个,提交各类别资源储量超7亿吨。其中,道真新民铝土矿床即是近年来探明的大型矿床之一,赋矿层位为中二叠统梁山组,矿体产于中下志留统韩家店组泥岩或上石炭统灰岩侵蚀面之上,矿床成因类型属于典型的古风化壳沉积型矿床。该矿床自2007-2011年实施预查-普查-详查以来,勘查单位主要围绕矿体(层)空间分布及资源量圈定开展工作,对矿床形成的主要控矿因素、成矿规律、矿石矿物学特征、矿层(体)及顶底板岩层中元素迁移与富集规律等方面缺乏系统研究,目前公开发表的文献仅有金中国、莫光员(2013)等对新民铝土矿的成矿地质背景、地质特征做了初步分析。本论文通过大量的野外地质调查、探槽和钻孔岩芯详细观察、地表出露含矿岩系追索、系统取样测试、室内资料综合整理,以期较全面总结成矿规律和主要控矿因素,揭示常量元素、微量元素在沉积成岩过程的迁移与富集机理,建立矿床地质地球化学演化模式,为相邻区找矿研究提供示范效果。通过研究获得以下主要成果及认识：(1)研究区从寒武系中上统—侏罗系地层发育完整,其中,中二叠统梁山组是含矿层位。新民矿区含矿岩系从上到下大致可以划分为上中下三段,上段为一薄层灰黑色含炭质泥岩、页岩,厚度0.3-1m,是矿层的直接顶板；中段为铝土矿层,由浅灰色～灰色铝土矿(岩)组成,厚度0.2-2.5m,是矿体的主要赋存段,矿体呈层状、似层状、透镜状产出；下段为灰绿色、绿色绿泥石,部分地段为铝土质粘土岩夹含铁质的绿泥岩,是矿层的直接底板。(2)矿区内土状一半土状、碎屑状、鲕状—豆鲕状构造主要在地表及浅表,深部以致密状为主,在断层构造发育区有土状—半土状、碎屑状构造矿石产出。矿石结构主要是豆鲕结构、碎屑结构、微-泥晶结构等。基于矿石结构、构造特征并结合前人研究,将新民铝土矿矿石分为豆鲕状铝土矿、土状—半土状铝土矿、碎屑状铝土矿、致密块状铝土矿四种自然类型；矿石中硫含量范围0.10%～7.00%,均值一般小于0.30%,铁含量范围1.20%～26.00%,主要集中在7%～9%,工业类型属于低铁低硫型(占矿石总量的44%)、含铁低硫型(占总量35.2%)和中铁低硫型铝土矿石(占总量的13.7%),三者之和达93.4%。矿石矿物组成主要以硬水铝石、软水铝石、高岭石为主,此外有少量伊利石、绿泥石,同时还有铁矿物及少量的副矿物石英。(3)地球化学分析显示,常量元素组成以Al3O2、SiO2和Fe2O3、TiO2为主,不同矿石样品之间含量有差异。Al2O3与TiO2呈强正相关关系,Al2O3与SiO2、TiO2呈强负相关关系、强正相关关系,Al2O3与Fe2O3呈负相关。矿石样品中富集Gd、Li、Be、Sc、V、Cr、Ga等元素,元素Ba、Ni、Sr、Zn略显富集,Co为贫化元素。Li、Ge和Ga在矿体中富集程度高,富集系数分别达36.60、5.97和3.06。含矿岩系不同空间微量元素富集、贫化(亏损)变化规律明显,稀土元素在矿层底部最富集,轻重元素间分馏作用强,具轻稀土富集特征。矿石中Ce呈正异常,Eu呈负异常。(4)通过研究稳定元素比值、稀土配分模式及Cr-Ni物源指示等,认为韩家店组泥岩为新民铝土矿提供了主要物源。通过探讨铝土矿形成的沉积演化过程及其过程中地球化学元素的活动规律,建立了地质地球化学演化模式,即韩家店泥岩(母岩)→铝土岩(中间产物)→铝土矿的形成。
[Abstract]:Bauxite is one of the main minerals in Guizhou, which is concentrated in Central Guizhou and North Guizhou. In recent years, a great breakthrough has been made in the exploration of bauxite ore prospecting in the area of Guizhou north railway in recent years. More than 10 super large bauxite ore deposits have been explored in succession, and more than 700 million tons of resources have been submitted to various types of bauxite deposits. One of the large ore deposits in Ming Dynasty, the ore bearing stratum is the middle two series of Liangshan formation, the ore body is on the middle and Lower Silurian hsijia group mudstone or the upper Carboniferous limestone erosion surface, the genesis type belongs to the typical paleo weathering crust deposit. Since 2007-2011 years, the exploration unit is mainly around the ore body (layer). There is a lack of systematic research on the main factors of ore control, metallogenic regularity, ore mineralogical characteristics, the migration and enrichment of elements in the strata (body) and the top and floor rock strata, and the only published literature at present is the gold China, Moguang (2013) and other metallogenic geological backs of Xinmin bauxite. This paper makes a preliminary analysis of the geological characteristics. In this paper, through a large number of field geological survey, exploration trough and borehole core detailed observation, the ground surface reveals ore bearing rock series, system sampling test, indoor data comprehensive arrangement, in order to comprehensively summarize the metallogenic regularity and main ore control factors, reveal the constant elements, trace elements in the sedimentary process of diagenesis. The mechanism of migration and enrichment and the establishment of geological and geochemical evolution model of ore deposits provide a demonstration effect for ore prospecting in adjacent areas. Through the study, the following main achievements and understanding are obtained: (1) the study area has developed completely from the middle and Upper Jurassic strata of the Cambrian system, of which the middle two stack Liangshan formation is a ore bearing stratum. The lower middle and middle three sections can be roughly divided, the upper part is a thin layer of gray black carbonaceous mudstone, the shale and the thickness 0.3-1m, the direct roof of the ore layer, the middle section of the bauxite layer and the light gray to gray bauxite (rock), the thickness of 0.2-2.5m, the main deposit section of the ore body, the ore body is layered, like lamellar, lenticular output, and the lower part is gray green. The green chlorite, in part, is the iron bearing green mudstone sandwiched in the Al clay rock and the direct floor of the ore layer. (2) the soil shape, clastic shape, oolitic and oolitic structure in the mining area are mainly in the surface and shallow surface, the deep part is dense, and in the fault tectonic zone, there are soil like semi soil shape, and the detrital structure ore output. Ore node. The main structure is the pea oolitic structure, detrital structure and micro muddy crystal structure. Based on the ore structure, structural characteristics and previous studies, Xinmin bauxite ore is divided into four types of natural types: pea oolitic bauxite, soil like semi soil bauxite, clastic bauxite and dense massive bauxite. The range of sulphur content in ore is 0.10% to 7%. Less than 0.30%, iron content range from 1.20% to 26%, mainly concentrated in 7% ~ 9%, industrial type belongs to low iron and low sulfur type (44% of the total ore), iron low sulfur type (accounting for 35.2%) and medium iron low sulfur bauxite ore (accounting for 13.7% of the total amount), three and 93.4%. ore deposits are mainly composed of hard diaspore, soft diaspore and kaolinite. There are a small amount of illite and chlorite, as well as iron minerals and a small amount of accessory mineral quartz. (3) geochemical analysis shows that the composition of the constant elements is Al3O2, SiO2, Fe2O3, TiO2, and there is a strong positive correlation between.Al2O3 and TiO2 in the different ore samples, and the strong negative correlation between Al2O3 and SiO2 and TiO2, strong positive correlation, Al2O3 and Fe. 2O3 is negatively correlated. The ore samples are enriched with Gd, Li, Be, Sc, V, Cr, Ga and other elements. The elements are enriched in Ba, Ni, Sr, and are enriched in the ore body, and the enrichment coefficient is enriched with different spatial trace elements in the ore bearing rock series, and the variation of dilution (loss) is obvious, and the rare earth elements are the most in the bottom of the ore layer. Enrichment, heavy fractionation between light and heavy elements, rich in light rare-earth enrichment. Ce is positive anomalies in the ore and negative anomalies in Eu. (4) through the study of the ratio of stable elements, the distribution pattern of rare earth and the indication of Cr-Ni source, it is considered that the mudstone of the Han Jia Jie formation provides the main source of material for Xinmin bauxite. In the course of the activity of geochemical elements in the process, the geological and geochemical evolution model has been established, that is, the formation of the Han Jia store mudstone (the parent rock), the bauxite (intermediate product) and bauxite.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.45

【参考文献】