会泽铅锌矿床深部矿化—蚀变岩相分带规律及找矿预测

发布时间：2018-01-01 21:00

  本文关键词：会泽铅锌矿床深部矿化—蚀变岩相分带规律及找矿预测　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 矿化-蚀变分带 矿化-蚀变指数 找矿预测 会泽超大型铅锌矿床 滇东北矿集区

【摘要】：会泽超大型铅锌矿床在滇东北铅锌多金属矿集区最具代表性。基于对该矿床成矿地质特征研究,应用大比例尺构造-蚀变岩相学填图方法,开展会泽铅锌矿床深部的矿化-蚀变分带及其地球化学特征研究,建立矿化-蚀变分带规律,并计算各带矿化-蚀变指数,结合构造地球化学研究,进行找矿预测。论文主要取得如下成果和认识:1)该矿床受断裂控制明显,矿体主要赋存于摆佐组(C1b)粗晶白云岩内的NE层间压扭性断裂带内。矿体两侧矿化-蚀变岩分带明显:随着离矿体距离的减小,矿化-蚀变程度增强。无论是矿体还是与其密切共生的蚀变带的展布均受到成矿期构造的严格控制,说明了构造-矿化-蚀变三者的密切关系。2)矿床主要蚀变类型为白云石化、方解石化、黄铁矿化、硅化等,矿化类型为闪锌矿化和方铅矿化。根据蚀变白云岩颜色、岩石组构、岩石学特征、与矿体的空间位置关系、矿化-蚀变强度等,矿床深部矿化-蚀变分带为:从围岩到矿体,呈现灰白色粗晶白云岩带(Ⅰ)→针孔状白云岩带(Ⅱ)→米黄色粗晶白云岩带(Ⅲ)→灰白色粗晶矿化白云岩带(Ⅳ)→铅锌矿化带(V)的变化规律;自围岩向矿体中心,白云石化、方解石化、黄铁矿化呈现出由弱变强的变化规律。而且,外围预测区的蚀变带的数量则相对减少,各带的蚀变程度较弱。3)应用元素质量平衡法计算各矿化-蚀变带之间的组分迁移特征:TFe、CaO、MgO、Pb、Zn几乎保持迁入富集状态。应用矿化-蚀变指数、迁入元素增长指数(Z)来研究矿化与蚀变的关系,矿化-蚀变指数(AI)、黄铁矿化指数(AITFe)、方铅矿化指数(AIPb)、闪锌矿化指数(AIZa)以及迁入元素TFe、Pb和Zn的增长指数值,由远矿到近矿逐渐增加,反映出铅锌矿化和黄铁矿化逐渐增强,围岩的白云石化指数(AIMgO)值比矿体高,反映出围岩经受过强烈的白云石化。各矿化-指数值的对比分析,发现各指数可以定量反映矿化带的矿化分布规律,研究AI值与矿化-蚀变的关系具有重要的找矿意义;4)对矿化信息提取的矿化-蚀变指数、Pb和Zn单元素异常以及矿化元素组合异常与实际矿体位置一致。其中,矿化-蚀变指数AI50%可表示闪锌矿化、方铅矿化及黄铁矿化。通过三种方法的对比研究,发现矿化-蚀变指数对于矿化信息的提取是可行的。结合矿床的地质条件,在1584中段小菜园勘查区运用矿化-蚀变指数、Pb和Zn单元素异常及构造地球化学异常进行找矿预测,得到3个找矿靶区。
[Abstract]:The Huize super large Pb-Zn deposit is the most representative of the Pb-Zn polymetallic deposit in northeastern Yunnan. Based on the study of the ore-forming geological characteristics of the deposit, a large scale tectonic-altered lithofacies mapping method is used. The mineralization-alteration zones and their geochemical characteristics in the depth of the Huize lead-zinc deposit are studied. The law of mineralization-alteration zones is established and the mineralization-alteration index of each zone is calculated, combined with the study of tectonic geochemistry. In this paper, the main achievements and understanding are as follows: (1) the ore deposit is obviously controlled by fault. The orebody is mainly located in the NE interlayer compression-torsional fault zone in the coarse dolomite of Chengzuo formation. The mineralization-altered rocks on both sides of the orebody are obviously zoned as the distance from the orebody decreases. The mineralization-alteration degree is enhanced. Both the distribution of the orebody and the alteration zone closely associated with the orebody are strictly controlled by the metallogenic tectonics. The main alteration types of the deposit are dolomitization calcite pyrite silicification and so on. The mineralization types are sphalerite and galena, according to the color of altered dolomite, rock fabric, petrological characteristics, the spatial relationship with orebody, mineralization-alteration intensity and so on. The mineralization-alteration zone in the deep part of the deposit is: from the surrounding rock to the orebody, the gray-white coarse grain dolomite belt (鈪，

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