草原覆盖区成矿成晕机理与找矿应用研究

发布时间：2018-06-26 20:42

本文选题：成矿成晕 + 找矿应用　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：大兴安岭中南段为典型的草原覆盖区,且成矿条件优越,素有“草原上的小南岭”之称。通过对该区三个典型热液型铅锌银多金属矿床(边家大院、拜仁达坝、花敖包特)的原生晕地球化学特征对比分析,探讨草原覆盖区成矿成晕机理,为该区的找矿勘查提供了理论支撑。取得主要成果如下:1、成矿成晕的系统对比分析表明:(1)储矿构造、热液的性质及热液阶段性活动对原生晕的规模和形态的影响较大。矿体(脉)和原生晕的形态及规模反映出拜仁达坝矿区和花敖包特矿区热液中成矿物质的原始浓度较高,成矿成晕强度较大,而边家大院矿区成矿成晕相对弱些;受构造产状的影响,边家大院矿区和拜仁达坝矿区的原生晕主要发育于矿体的上盘,而花敖包特矿区矿体(脉)两盘原生晕发育规模较相当;含矿热液阶段性沉淀是轴向分带序列中前缘晕(或尾晕)元素“反向分带”的主要原因。(2)矿区赋矿围岩中成矿元素(Pb、Zn、Ag)的含量、赋矿围岩铅同位素与矿石铅同位素的对比,以及构造对矿体的约束等方面的特征表明,赋矿围岩对成矿物质的供应微弱。(3)成矿作用过程中,随着温度、压力等物化条件的改变,Ag、Sn等元素赋存矿物的改变是其相关系数发生变化的根本原因。(4)边家大院矿区B-B′勘探线和拜仁达坝西矿区16号勘探线浓度分带图上均反映出原生晕在保存过程中受到后期岩体(脉)的改造。2、原生晕特征研究表明,边家大院矿区A-A′勘探线南东方向深部可能隐伏着多阶段的矿脉群;B-B′勘探线控制的石英斑岩体为富集Pb、Zn、Ag、Cu、Sn、Mo等元素的地质体;拜仁达坝西矿区16号勘探线北西方向深部为热液的源区,深部形成高温元素(W、Mo、Sn等)矿种的潜力较大。3、以矿区及区域地质特征为基础,结合区域地球化学异常和矿床(点)分布特征,提出了林西地区(黄岗梁-大井地区)、拜仁达坝地区,以及花敖包特地区综合找矿标志。
[Abstract]:The central and southern part of the Daxing'an Mountains is a typical grassland covering area, and the ore-forming conditions are superior, so it is known as "Xiaonanling on the grassland". Based on the comparative analysis of the geochemical characteristics of primary halo in three typical hydrothermal lead-zinc-silver polymetallic deposits (Bian Jia Yuan, Bayern Daba, Hua-ao Bao et al), the mechanism of ore-forming halo in steppe covering area is discussed. It provides theoretical support for prospecting and exploration in this area. The main results are as follows: (1) the ore-storage structure, hydrothermal properties and hydrothermal activities have great influence on the size and morphology of primary halo. The shape and scale of orebody (vein) and primary halo reflect that the original concentration of ore-forming material in hydrothermal solution is higher and the intensity of ore-forming halo is higher in Bayern Daba and Hua-ao Baotte mining areas, but the ore-forming halo is relatively weak in Bian Jia Dayuan mine area. Under the influence of tectonic occurrence, the primary halo in Bian Jia Yuan and Bayern Daba mining area is mainly developed on the upper plate of orebody, while the two primary halos in Huaaobute mine area have the same development scale. The precipitation of mineral-bearing hydrothermal phase is the main reason for the "reverse zoning" of the leading halo (or tail halo) elements in the axial zoning sequence. (2) the content of ore-forming elements (PbPb-Zn ~ (+) Ag) in the host rock of the mining area, and the comparison between the lead isotopes of the ore-bearing surrounding rock and the lead isotope of the ore. The characteristics of structural constraints on orebodies show that the supply of ore-bearing rocks to the ore-forming materials is weak. (3) during the mineralization process, with the temperature, The change of pressure and other physical and chemical conditions is the fundamental reason for the change of correlation coefficient. (4) the concentration zonings of B-B' exploration line in Bian Jia Yuan mining area and exploration line 16 in Bayern Dabaxi mining area are reflected in the concentration zoning diagram. The primary halo was modified by the late rock mass (vein) in the process of preservation. The study on the characteristics of the primary halo shows that, The quartz porphyry controlled by the B-B' exploration line in the south and east direction of the A-A 'exploration line of the Bian Jia Yuan mining area may be a geological body enriched in elements such as PbPbZn, Ag, Cu, Sn, Mo and so on. The depth of No. 16 Prospecting Line NW of Bayern Dabaxi Mining area is the source of hydrothermal solution, and the potential of forming high temperature element (WPMOA Sn, etc.) in the deep part is high. 3, which is based on the geological characteristics of the mining area and the region. Combined with the regional geochemical anomalies and the distribution characteristics of the deposits (points), the comprehensive prospecting criteria for the Linxi area (Huanggangliangliang-Dajing area), Bayern Daba area and Hua-ao Baotte area are put forward.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P632;P612

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