内蒙双尖子山银多金属矿矿石矿物与成矿期次研究

发布时间：2018-04-05 10:01

本文选题：双尖子山　切入点：银多金属矿　出处：《中国地质大学(北京)》2017年硕士论文

【摘要】：双尖子山银铅锌多金属矿床位于内蒙古自治区赤峰市巴林左旗北部,兴蒙造山带北造山带和南造山带的夹持部位。银远景资源量达2万吨以上,属超大型矿床,是近年来在大兴岭成矿带南段发现的最大银多金属矿床,曾受到地质界的高度关注。前人虽对矿床的基本特征、成矿年龄、银的赋存、地球化学特征等进行过初步探讨,但在成矿期次与成矿时代上仍然存在较多争议,特别是对早期的低品位浸染状矿化缺乏研究。本文在前人研究的基础上,以低品位微细浸染状矿化为重点,利用光薄片和电子探针的方法,辅助化学元素图解,通过对造矿矿物的矿物学、矿相学和元素地球化学的研究,探讨了不同期次、不同矿化阶段的硫化物矿化特征,为成矿期次与成矿过程研究提供了基础信息。其主要认识如下:(1)双尖子山银多金属矿存在两种不同类型的矿石矿物组合:第一类为微细浸染状矿石,其矿石矿物包括黄铁矿与黄铜矿,银品位较低,一般只有几十至一、二百多克/吨;第二类为细脉网脉状、团块状矿石,其矿石矿物组合主要为方铅矿、闪锌矿和黄铁矿组合,银品位较高,可达数百至数千克/吨。(2)微细浸染状矿石中的黄铁矿以单晶或集合体形态呈它形-半自形星点状分布于灰黑色板岩或石英脉中,其钴镍比值多在0.5-2.9之间,银矿化与铅锌矿化关系不密切;细脉网脉状、团块状矿石中黄铁矿多以集合体形态与闪锌矿、方铅矿共生,其钴镍比值在1.55-12.44之间,局部高达32,其形成与岩浆热液密切相关,银矿化与铅锌矿化密切相关。(3)两种不同类型的矿石矿物组合代表了两期矿化产物,早期为微细浸染状矿化具有分布范围广,银矿化品位低,银的产出与硅化关系密切;晚期为细脉网脉状、团块状矿化,其本质是成矿热液活动带来新的硫化物矿化,以及原有矿化进一步富集,方铅矿与闪锌矿呈现多阶段矿化的特点,大致呈现高温相至低温相转变的趋势,银矿物呈现出从复杂硫化矿物到简单辉银矿物或单质银矿物的趋势。
[Abstract]:The Shuangjianzishan silver-lead-zinc polymetallic deposit is located in the north of Balin Zuo Banner, Chifeng City, Inner Mongolia Autonomous region, and is located in the north orogenic belt and the southern orogenic belt of Xingmeng orogenic belt.Silver potential resource is more than 20 thousand tons, which is a super large deposit. It is the largest silver polymetallic deposit discovered in the southern section of Daxingling metallogenic belt in recent years, and has been highly concerned by geological circles.Although the basic characteristics of ore deposits, metallogenic age, occurrence of silver, geochemical characteristics and so on have been preliminarily discussed, there are still many controversies in the metallogenic epoch and metallogenic epoch.Especially in the early stage of low grade disseminated mineralization lack of research.On the basis of previous studies, this paper focuses on low-grade micro-disseminated mineralization, using the method of light sheet and electron probe to assist with the diagram of chemical elements, through the study of mineralogy, mineralogy and element geochemistry of ore-forming minerals.The characteristics of sulphide mineralization in different stages of mineralization are discussed, which provides basic information for the study of metallogenic stages and processes.Its main understanding is as follows: (1) there are two different types of ore mineral assemblages in the Shuangjianzishan silver polymetallic ore deposit: the first type is micro-disseminated ore, the ore minerals of which include pyrite and chalcopyrite, and the silver grade is relatively low, generally only tens to one.More than 200 g / t; the second type is vein-netted, massive ore, the mineral assemblages are mainly galena, sphalerite and pyrite assemblage, and the silver grade is relatively high.Pyrite in fine disseminated ores is distributed in the form of single crystal or aggregates in the form of isomorphic and semi-automorphic star dots in gray black slate or quartz veins, and the ratios of cobalt and nickel are mostly between 0.5-2.9,The relationship between silver mineralization and lead-zinc mineralization is not close, the pyrite in the vein-like veins and lumps is mainly associated with sphalerite and galena, the ratio of cobalt and nickel is between 1.55-12.44, and the ratio of cobalt and nickel is as high as 32.The formation of pyrite is closely related to magmatic hydrothermal solution.Silver mineralization is closely related to lead-zinc mineralization. Two different types of ore mineral assemblages represent two stages of mineralization products. The early micro-disseminated mineralization has a wide range of distribution, low grade of silver mineralization, and close relationship between silver production and silicification.The late stage is vein-net vein and massive mineralization. The essence of the mineralization is that the ore-forming hydrothermal activity brings about new sulfide mineralization, and the original mineralization is further enriched, and galena and sphalerite show the characteristics of multi-stage mineralization, and the mineralization of galena and sphalerite is characterized by the multistage mineralization of galena and sphalerite.The silver minerals show a trend from complex sulphide minerals to simple pyroxene or simple silver minerals.
【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】：2017
【分类号】：P618.2

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