青海省玉树多彩地区米扎纳能铅锌矿矿床成因及矿化富集规律研究

发布时间：2018-06-15 07:41

本文选题：青海玉树地区 + 米扎纳能铅锌矿　；参考：《吉林大学》2017年硕士论文

【摘要】：米扎纳能铅锌矿床是近年来在多彩地区新发现的小型铅锌矿床,通过初步估算,2015年米扎纳能铅锌矿334资源量为3.57万吨,其中Pb资源量3.34万吨,Zn资源量0.24万吨,Ag 740千克,并且具有重大的找矿潜力,该区具备寻找中型碳酸盐岩型富铅锌矿的找矿前景。但该地区理论研究非常薄弱,矿床类型的不确定性和控矿规律的模糊性等因素制约了找矿工作的进展,因此对该矿床进行全面的深入研究是十分必要的,提高矿床的整体研究程度,为下一步勘查工作提供理论指导,为多彩地区找矿突破提供基础参考。本文主要是在野外调研工作基础之上,查明该矿区的区域地质背景,矿区地质特征、矿床地质特征,并对矿床进行了流体包裹体、单矿物同位素和电子探针分析,查明了矿床形成物理化学条件,流体来源以及成矿物质来源,深入探讨矿床成因,进而总结矿化富集规律。研究区位于西南三江北延,是我国新兴的重要矿产资源基地。大地构造位置位于可可西里—金沙江缝合带与乌兰乌拉湖—玉树断裂之间,呈北西西向分布于吓根龙—巴塘一带,属三江多金属成矿带通天河印支期铜、铅、锌成矿亚带。矿体主要赋存于晚三叠世结扎群甲丕拉组,岩性包括中厚层灰岩段、薄层灰岩-砂岩互层岩段,其中中厚层灰岩段为主要富矿围岩。米扎纳能铅锌矿矿区位于米扎纳能复式背斜核部,分布在该背斜南翼F2断层为该区的主要导矿构造,同时又是局部容矿构造,F2断裂控制了Ⅰ矿体的展布情况,矿体主要分布在该断裂带及其附近岩石裂隙中。该背斜受近南北向挤压力影响,在背斜核部易产生虚脱空间,为成矿提供有利场所,为该矿床的容矿构造,背斜核部及其附近可能成矿,下一步具体工作位置应注重该复式背斜的核部虚脱构造部位。流体包裹体特征显示米扎纳能铅锌矿流体包裹体主要以气液两相的盐水溶液包裹体为主,成矿流体具有低温(120～190℃)、低盐度(0.8～2.4%NaCl)和低密度(0.89～0.96g/cm3)特征,从早到晚温度和盐度具有微小的逐渐降低趋势,主成矿阶段的压力为7.94-11.25Mpa,深度为0.79～1.22km,流体包裹体特征显示米扎纳能铅锌矿流体主要来源于大气降水。硫同位素特征表明硫的来源具有不均一性,2件重晶石硫主要来源于海相蒸发岩,4件金属硫化物硫的来源既有地层硫的特点又具有岩浆硫的特点,主要地层硫为主。铅同位素结果表明,铅具有混合铅特征,与硫同位素结果基本一致。对黄铁矿、闪锌矿和方铅矿进行电子探针分析,结果显示出黄铁矿、方铅矿、闪锌矿均具有热液成因的特点又具有沉积环境的特点,与硫、铅同位素结果相符合,说明成矿物质具有混合来源的特征。综上所述,通过对米扎纳能铅锌矿床流体包裹体、硫-铅同位素、电子探针分析,确定该矿床属于中低温热液铅锌矿床。通过对比临区同类型矿床,如多日茸铅锌矿、东莫扎抓铅锌矿等,米扎纳能铅锌矿矿床特征与其特征相似,说明米扎纳能铅锌矿与多日茸铅锌矿和东莫扎抓铅锌矿(34Ma)为同一时期形成的矿床,同时又与区域上查勇铜多金属矿区的辉长岩年龄(33.1±1.8Ma)接近,认为米扎纳能铅锌矿床的形成与同一时期的中酸性岩浆活动有关,形成于渐新世。
[Abstract]:The Mi Zha nnnnnnun lead zinc deposit is a newly discovered small lead zinc deposit in the colorful area in recent years. Through preliminary estimation, in 2015, the 334 resources of Mi Zha nnnnnnn lead zinc mine were 35 thousand and 700 tons, of which Pb resources were 33 thousand and 400 tons, Zn resources were 2 thousand and 400 tons, Ag 740 kilograms, and had great potential for prospecting. The area was found to find medium carbonate rich lead. The prospecting prospect of zinc ore is very weak, the uncertainty of the type of ore deposit and the fuzziness of the ore control law have restricted the progress of the prospecting work. Therefore, it is necessary to carry out a comprehensive and thorough study of the ore deposit, so as to improve the overall research range of the deposit and provide theoretical guidance for the next exploration work. On the basis of field investigation, this paper is mainly on the basis of field investigation, to find out the regional geological background, geological features and geological features of the mining area, and to carry out fluid inclusions, single mineral isotopes and electron probe analysis on the deposit, and find out the physical and chemical conditions for the formation of the deposit, and the source of the fluid. As well as the source of metallogenic material, the genesis of the deposit is deeply discussed, and then the regularity of mineralization and enrichment is summarized. The study area, located in the north of Southwest Sanjiang, is a new important mineral resource base in China. The position of the geodetic structure lies between the cocoa West Jinsha River suture zone and the Ulan Ulan Lake Yushu fault. The belt is the copper, lead and zinc metallogenic subbands of the Tong Tian river of the Tong Tian River in the Sanjiang polymetallic metallogenic belt. The ore bodies mainly occur in the late three fold ligation group methila group, including the middle thick layer limestone section and the thin limestone sandstone interbedded rock section, and the middle thick layer limestone section is the main rich rock. The Mi Zha nnnenergy lead-zinc mine is located in the Mi Zha nnnenergy complex anticline core. The F2 fault located in the south wing of the anticline is the main ore guide structure in the area, and it is also a local ore bearing structure, and the F2 fracture controls the distribution of the orebody. The ore body is mainly distributed in the fracture zone and the rock fissure near it. The anticline is affected by the near North and South pressure, and the void space is easily produced in the nucleus of the anticline, which is beneficial to the mineralization. The site, which is the ore bearing structure of the deposit, may mineralization in the nucleus and near the anticline, and the next specific position should pay attention to the dislocation structure of the nuclear part of the compound anticline. The fluid inclusions in the fluid inclusions show that the fluid inclusions of the Mi Zha nnnnenergy lead and zinc ore are mainly the saline solution inclusions of gas-liquid two phase, and the ore-forming fluid has a low temperature (120~19 0 C), low salinity (0.8 ~ 2.4%NaCl) and low density (0.89 ~ 0.96g/cm3), the temperature and salinity from morning to night have a slight decreasing trend. The pressure of the main metallogenic stage is 7.94-11.25Mpa and the depth is 0.79 ~ 1.22km. The fluid inclusion characteristics show that the fluid of Mi Zha nnnenergy lead zinc ore is mainly derived from the atmospheric precipitation. The source of sulfur is inhomogeneity, and 2 pieces of barite sulfur are mainly derived from marine vaporized rock. The source of 4 metal sulphide sulfur is characterized by both sulfur in formation and the characteristics of sulfur in the main strata. Lead isotope results show that lead has the characteristics of mixed lead and is basically consistent with the results of sulphur homotomes. The results of electron probe analysis show that pyrite, galena and sphalerite have characteristics of hydrothermal genesis and sedimentary environment, which conforms to sulfur and lead isotopes, indicating that the minerals have the characteristics of mixed sources. In summary, the fluid inclusions of the mithenna lead-zinc deposit, sulfur lead isotopes, electrons It is determined that the deposit belongs to the middle low temperature hydrothermal lead-zinc deposit, and the characteristics of the Mizzana energy lead zinc ore deposit are similar to that of the same type deposit, such as the multi day lead zinc deposit and the East mozai lead zinc deposit. It shows that the Mi Zha nnnnable lead zinc mine was formed in the same period as the multi day lead-zinc mine and the East mozan catch lead zinc mine (34Ma). The deposit, at the same time, is close to the age of gabbro (33.1 + 1.8Ma) in the area of Zha Yong copper polymetallic ore area. It is thought that the formation of Mi Zha nnnnnn Pb Zn deposit is related to the intermediate acid magma activity of the same period and formed in the Oligocene.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.4

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