云南建水苏租—暮阳铅锌矿床地球化学特征及成因分析

发布时间：2018-02-14 04:02

本文关键词： 矿床地质特征地球化学矿床成因建水苏租-暮阳　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：云南建水苏租-暮阳铅锌矿区位于康滇地轴南段东缘"建水-盘溪古隆起"构造带上。东临小江断裂,南临弥勒-师宗断裂,总体构造线为北北东向。区内现已发现10余处铅锌矿床(点)构成北东向的矿带。百里背斜贯穿全境,其中苏租-暮阳铅锌矿床分别位于百里背斜的两翼。区内地层总体走向北北东,表现为倾向南东的单斜构造。该成矿带的铅锌矿床集中产于中泥盆曲靖组的白云岩上。本文选取苏租-暮阳铅锌矿床为研究对象,主要通过矿床地质特征、流体包裹体、元素地球化学、同位素地球化学特征等方面研究,同时结合已有资料进行成矿分析,旨在为苏租-暮阳铅锌矿床的成因提供地球化学方面的依据,本论文取得以下方面的成果和认识:1.研究区铅锌矿床主要赋存于中泥盆系曲靖组碳酸盐岩中。岩性以中至厚层状白云岩、灰岩、含生物礁灰岩为主,矿体整体呈层状、似层状产出。矿体的产出受构造和地层控制。2.矿石矿物组成原生金属硫化矿物主要为方铅矿和闪锌矿,次为黄铁矿及少量黄铜矿、辉银矿;非金属矿物主要为白云石、方解石,其次为石英。围岩蚀变以碳酸盐化为主。矿石主要结构为细晶结构、交代溶蚀结构、交代残留结构、他形粒状结构。矿石主要构造为团块状构造、网脉状构造、星散浸染状构造、斑点状构造。3.流体包裹体地球化学特征变现出苏租-暮阳铅锌矿床的成矿流体为:中-低温、低盐度、低密度的NaCl-H2O体系,地壳浅部环境成矿。4.苏租暮阳铅锌矿床硫、铅同位素均表现出多来源特征:硫的主要来自来自赋矿围岩和各时代的碳酸盐岩;铅同位素来源于下地壳和造山带,且铅源参数特征更接近于造山带,同时混合了一定的深部物质,铅同位素组成反映出矿床的成矿金属是多来源的。苏租-暮阳铅锌矿床成矿流体中C-O同位素来自海相碳酸盐岩经溶解作用,在成矿过程中碳酸盐岩作为金属元素的载体发生了溶解-运移-再沉积作用。结合单矿物锶同位素研究表明,苏租-暮阳铅锌矿床成矿物质多来源混合,主要来自各时代沉积的碳酸盐岩和流经基底岩石。所选矿床的成矿年代大致相当于晚印支期-早燕山期之间。5.根据苏租-暮阳铅锌矿床的地质特征、镜下矿物结构构造特征,将该区成矿期次可以划分三个层次即沉积成岩期,热液成矿期和表生氧化期。再结合矿床地球化学特征、流体包裹体特征初步厘定苏租-暮阳铅锌矿床为沉积-混合热液型铅锌矿床。
[Abstract]:Suzhu-Wuyang lead-zinc mine area in Jianshui, Yunnan Province is located in the "Jianshui-Panxi paleouplift" tectonic belt in the eastern margin of the southern section of the Kangdian axis. It is bounded by the Xiaojiang fault to the east and the Maitree-Shizong fault to the south. The overall tectonic line is NNE. More than 10 Pb-Zn deposits (points) have been found in the area to form a NE-trending ore belt. The hundred li anticline runs through the whole area. The Suzhuo-Wuyang Pb-Zn deposit is located on the two flanks of the hundred Li anticline respectively. The lead-zinc deposit in the metallogenic belt is concentrated on dolomite in the Qujing formation of the middle Devonian. The Suzhuang-Wuyang Pb-Zn deposit is selected as the research object in this paper, mainly through the geological characteristics of the deposit, fluid inclusions, Element geochemistry, isotopic geochemical characteristics and metallogenic analysis are carried out in combination with the available data in order to provide geochemical basis for the genesis of the Suzhuang-Wuyang lead-zinc deposit. This paper has obtained the following achievements and understandings: 1. The lead-zinc deposits in the study area are mainly located in carbonate rocks of the Qujing formation of the Middle Devonian system. The lithology of the deposits is meso-thick layered dolomite, limestone, reef bearing limestone, and the whole orebody is stratiform. The ore body is controlled by structure and strata. The ore minerals consist of galena and sphalerite, followed by pyrite and a small amount of chalcopyrite, and the nonmetallic minerals are dolomite and calcite. The main structure of the ore is fine crystal structure, metasomatic solution structure, metasomatic residual structure, heteromorphic granular structure. The geochemical characteristics of fluid inclusions show that the ore-forming fluids of Suzhuang-Wuyang lead-zinc deposit are NaCl-H2O systems of medium-low temperature, low salinity and low density. The sulfur and lead isotopes of the Suzhuangyang lead-zinc deposit are characterized by multiple sources: sulfur mainly comes from host rocks and carbonate rocks of various ages, and lead isotopes are derived from the lower crust and orogenic belts, and lead isotopes are derived from the lower crust and orogenic belts. The characteristics of lead source parameters are closer to the orogenic belt, and some deep materials are mixed. The isotopic composition of lead reflects that the metallogenic metals of the deposit are multi-source. C-O isotopes in the ore-forming fluids of Suzhuang-Wuyang Pb-Zn deposit are derived from the dissolution of marine carbonate rocks. During the process of mineralization, carbonate rocks as the carrier of metal elements have dissolution-migration-redeposition process. Combined with strontium isotope study of single mineral, it is shown that the ore-forming materials of Suzhuang-Wuyang lead-zinc deposit are mixed from multiple sources. The ore-forming age of the selected deposit is approximately equal to that of the late Indosinian and early Yanshanian epoch .5.According to the geological characteristics of the Suzhuang-Wuyang lead-zinc deposit, the structural characteristics of minerals are obtained under microscope. The metallogenic stages in this area can be divided into three levels: sedimentary diagenesis, hydrothermal mineralization and supergene oxidation. The characteristics of fluid inclusions indicate that the Suzhuang-Wuyang Pb-Zn deposit is a sedimentary-mixed hydrothermal Pb-Zn deposit.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.4

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