甘肃阳山金矿金的化学相态研究及其勘查意义

发布时间：2018-03-03 08:27

本文选题：阳山金矿　切入点：化学相态　出处：《吉林大学》2015年硕士论文　论文类型：学位论文

【摘要】：阳山金矿，地处川陕甘交界的特大类卡林型金矿，既具有卡林型金矿的典型特征，也具备造山型金矿的显著特点。本文在野外地质调查基础上，利用现代分析测试技术，对区内与成矿作用有关的地质体（岩石、矿石）元素丰度特征、元素组合特征和成矿元素化学相态分布特征进行了系统的研究，建立起新的地球化学找矿标志，为开展典型矿区深部及外围盲矿体地球化学探测提供依据。对区域岩石进行主量元素和微量元素分析，发现区域岩石中显著富集Pb、As、Bi、Sb、W、Au和CaO，极度贫化Cr、Mn、Na2O、MgO和SiO2；泥盆系是最富集微量元素的层位，其Au、Sb、As、Bi、W分异程度高，富集系数大，出现明显的预富集，泥盆系可能是矿源层；以富集系数大于1.5作为划分标准结合区域岩石因子分析结果确定Au、Sb、As、Bi、W是区域岩石典型的微量元素组合。对矿区矿石和围岩进行微量元素分析，发现Au、As、Sb、Bi、W、Hg在阳山金矿床内强烈富集，极度分异，其中Au富集系数1579.27，变异系数3.08，具有很好的成矿潜力；与三河口组围岩相比，各种类矿石中，Au、As、Sb、Hg含量都明显偏高，其中石英脉型矿石金平均含量最高，为23.13×10-6。其次是蚀变花岗斑岩型矿石，其金含量为8.48×10-6，Mn、Cu、Zn、Pb、Cd等元素含量则与三河口组地层无明显差别；矿石含量特征和元素聚类分析结果显示Au、As、Sb、Bi、Hg、W是阳山金矿区成矿元素组合。对区域水系沉积物中的金进行化学相态分析，结果显示：水系沉积物中金以水溶态、离子交换态、碳酸盐结合态、有机质结合态、铁锰氧化物结合态、游离态、硫化物结合态、残渣态这8种相态存在。其中，游离态是金最主要的化学相态。主要赋矿的泥盆系三河口组和石炭系地层水系沉积物中游离态所占比例（67.42%，43.61%）明显高于其他层位（1.40%～31.03%）。根据不同地层水系沉积物中金相态分布差异，可以缩小成矿靶区，，确定与该区成矿作用关系密切的地层对矿区隐伏矿体上方典型土壤剖面中的金进行化学相态分析，结果显示：与水系沉积物类似，土壤中金的8种相态均可检出，游离态是矿区土壤中金最主要的化学相态，其次为硫化物结合态。游离态金在全量金中所占比例的极大值点，或活动态金在全量金中所占比例的极小值点与深部金矿体的位置相吻合。可以利用游离态金所占比例的高值点（活动态金所占百分比的低值点）与金矿体的对应关系可以指导地球化学找矿。对矿区岩石中的金进行化学相态分析，结果显示：地层岩石和岩体岩石金的化学相态特征与区内矿石金的化学相态特征存在着显著不同：硫化物态在矿石中占49.27%，在岩体中占40.54%，在地层岩石中占20.51%；成矿可利用相态（游离态、碳酸盐结合态、水溶态和硫化物态）在岩体中占68.86%，在矿石中占65.24%，在地层岩石中占38.89%；不同类型矿石中金相态分布存在差异，但是其硫化物态和成矿可利用相态所占比例均很高，分别在47.33%～50.36%，51.71%～86.03%。利用上述岩石，矿石中金的相态分布特征，可探讨各类典型矿石的形成地质作用过程，确定与矿区成矿作用关系密切的地质体，从而建立起典型矿集区地球化学找矿标志，为开展典型矿集区大型矿床深部及外围盲矿体地球化学探测提供依据。
[Abstract]:Yangshan gold deposit, located in large class of Shaanxi Gansu Sichuan at the junction of the Carlin type gold deposit, which has typical features of Carlin type gold deposit, also have the remarkable characteristics of orogenic gold deposits. Based on the field geological investigation, using modern analysis and testing technology of geological bodies associated with mineralization in the region (rock, ore) element abundance characteristics of elements assemblage characteristics and metallogenic elements of chemical phase distribution characteristics were studied systematically, establish new geochemical prospecting criteria, to provide evidence for developing typical mining areas in the deep and periphery of blind ore geochemical exploration.
Analysis of major and trace elements of regional rock, rock region found significant enrichment of Pb, As, Bi, Sb, W, Au and CaO, Cr Mn, Na2O extreme dilution, MgO, and SiO2; Devonian is the enrichment of trace elements Au, Sb, horizon, As, Bi. W high degree differentiation, enrichment coefficient, apparent enrichment, Devonian may be the source of ore; the enrichment coefficient is greater than 1.5 as the division standard is determined according to the results of factor analysis of regional rock Au, Sb, As, Bi, W is a combination of trace elements in typical rock areas.
The trace element analysis, Au, As, Sb, Bi, W of ore and rock Hg in Yangshan gold deposit in strong enrichment, extreme difference, the enrichment coefficients of Au 1579.27, the coefficient of variation was 3.08, with the mineralization potential well; compared with group three estuaries surrounding rock, various types of ore. Au, As, Sb, Hg were significantly higher, the quartz vein type ore gold highest average concentration is 23.13 * 10-6. followed by altered granite porphyry ore, the gold content is 8.48 * 10-6, Mn, Cu, Zn, Pb, Cd elements and three river formation have no obvious difference the results of cluster analysis; ore content features and elements of Au, As, Sb, Bi, Hg, W is the Yangshan gold ore elements.
On the regional stream sediment in gold by chemical phase analysis, results showed that the sediment of gold with water soluble, exchangeable, carbonate bound, organic matter bound, Fe Mn oxides, free, sulfide bound residue, the 8 phase. The free state is gold is the most main chemical phases. The main ore of Devonian and Carboniferous strata group three estuarine sediments in the middle reaches of the state proportion (67.42%, 43.61%) was significantly higher than that of other layers (1.40% ~ 31.03%). According to the phase distribution of different strata sediment gold metallogenic target area can be reduced, identified closely the stratigraphic relationship with the mineralization
The profile of the typical soil in mine concealed ore deposits of gold in chemical phase analysis, results showed that: similar sediments, 8 phases can be detected in the soil, the free state is the main gold mining area soil chemical phase, followed by sulfide bound. The maximum point of free gold in the full amount of gold the proportion of the total activity or state gold in gold in the proportion of the minimum point and deep ore body position coincide. High values can make use of free gold proportion (low value of the percentage of the activity state of gold) and gold body can guide the corresponding relationship geochemical prospecting.
On the rocks of gold in chemical phase analysis, results showed that significantly different chemical phase characteristics and ore zone of gold rock and rock chemistry of gold phase characteristics exist: the sulfide in the ore accounted for 49.27%, accounted for 40.54% in the rock, accounting for 20.51% in the formation of mineralization can be; using phase (free state, carbonate bound, water soluble and sulfide) accounted for 68.86% in the rock, accounting for 65.24% in the ore, accounting for 38.89% in the formation of gold ore; different types of phase distribution are different, but the sulfide mineralization and available phase proportion is very high in 47.33% ~ 50.36%, respectively, 51.71% ~ 86.03%. by the rock, gold in the ore phase distribution characteristics, can investigate the formation of geological processes of various typical ore, determine the geological body and mine mineralization closely, so as to establish a code The geochemical prospecting marks of the type ore gathering area provide the basis for the geochemical exploration of the deep and peripheral blind ore bodies of the typical large ore deposits.

【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】：P618.51

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