湘西李梅铅锌矿床流体特征及其成矿过程分析

发布时间：2018-05-04 02:08

本文选题：流体包裹体 + 成矿过程　；参考：《长安大学》2017年硕士论文

【摘要】：湘西李梅铅锌矿位于上扬子地块与江南地块间过渡地带的武陵山弱变形带上,是湘西-鄂西铅锌成矿带北部的花垣矿集区中一个十分重要的MVT型铅锌矿床。矿区主要出露中、上寒武统娄山关组(?2-3l)、中寒武统高台组(?2g)和下寒武统清虚洞组(?1q)地层,铅锌矿产于寒武统清虚洞组灰岩层中,受构造岩相控制特征明显。选择《湘西李梅铅锌矿床流体特征及其成矿过程分析》作为学位论文题目,具有重要的地质科学研究意义和地质找矿参考价值。依托《湘西张家界花垣整装勘查区矿田地质研究和找矿》项目,在野外地质勘察和构造测量的基础上,系统的开展室内镜下鉴定和测试分析综合研究,以矿区构造和岩石特征为主要研究目标,按时提交了研究课题报告和学位论文。研究主要取得如下进展:1.将李梅铅锌矿成矿过程划分为四个阶段:根据野外观察到的不同类型矿化穿插关系和分布特征、显微镜下详细的矿石结构构造、矿物结晶状态和组合特征,将该矿床的成矿过程划分为以下四个阶段。闪锌矿沿缝合线晶出阶段:该阶段形成的矿石主要为稀疏浸染状矿石,形成于早期阶段。闪锌矿-方铅矿沿裂隙、孔隙交代充填阶段:该阶段成矿作用较强,成矿物质集中。金属矿物主要为闪锌矿,其次为方铅矿和黄铁矿。脉石矿物主要为方解石,次为重晶石、萤石等。该阶段形成的矿石主要为网脉状、斑脉状矿石,形成于主要成矿阶段。方铅矿-方解石充填阶段:该成矿阶段矿物组合简单,金属矿物只有方铅矿和少量闪锌矿,脉石矿物仅见方解石。热液方解石脉沿裂隙侵入阶段:该阶段为后期热液方解石脉侵入到裂隙、孔隙等中结晶。对成矿起到破坏的作用。2.完成了李梅成矿阶段流体特征的分析:本次所采样品中都有一定数量流体包裹体发育,主要为气液两相共存的包裹体。闪锌矿-方铅矿沿裂隙、孔隙交代充填阶段,气液两相包裹体盐度介于1.1%-23.1%Na Cleqv.,均一温度介于78-342℃,成矿流体流体的密度为0.70-1.14g/cm3,成矿压力介于194.30-960.19bar。方铅矿-方解石充填阶段,气液两相包裹体盐度介于1.4%-23.1%Na Cleqv.,均一温度介于68-259℃,成矿流体流体的密度为0.88-1.15g/cm3,成矿压力介于190.99-727.13bar。热液方解石脉沿裂隙侵入阶段,气液两相包裹体盐度介于3.71%-23.18%Na Cleqv.,均一温度介于76-227℃,成矿流体流体的密度为0.91-1.12g/cm3,成矿压力介于199.46-637.29bar。包裹体研究表明,李梅矿床成矿过程中流体包裹体均一温度有所降低,盐度均值变化较弱,其盐度峰值均出现在21.0%-23.0%区间。3.指出了李梅MVT型铅锌矿区沉积环境特征:以李梅铅锌矿区外围清虚洞组和高台组不同层位的碳酸盐岩为研究对象,主要采用岩石主量、微量元素地球化学分析,得出了李梅铅锌矿区清虚洞期到高台期碳酸盐岩沉积特征表现为海水逐渐退去的趋势。在清虚洞期-高台期研究区碳酸盐岩沉积受陆源碎屑和成岩作用影响有限,古海洋环境为氧化环境、古海水为暖水环境、古气候由潮湿向干旱转换的变化,也正是由于这样的海水环境导致了大量藻类生物的繁殖,从而沉积形成藻灰岩,成为主要赋矿岩石。4.编制了花垣矿田矿体等高线图,分析了李梅铅锌矿床成矿过程:以岩心钻孔数据为依据制图,深化了深部矿床的展布特征及构造演化成矿的认识。李梅MVT型铅锌矿床容矿围岩以藻灰岩为主,产在雪峰期-加里东期构造运动形成的北东-北北东向平缓褶皱、断裂构造带中。含矿热液从下伏地层在热力大的驱动下,沿断裂带向上运移,在含有裂缝、孔隙的藻灰岩中反生还原反应,置换出铅锌等元素,使其富集成矿。矿床具有明显后生特征。
[Abstract]:Xiangxi Li Mei lead zinc mine is located in the weak deformation zone of the Wuling Mountain in the transition zone between the upper Yangtze block and the Jiangnan massif. It is a very important MVT type lead-zinc deposit in the Huayuan ore collection area in the northern part of the Xiangxi - Western Hubei lead zinc metallogenic belt. The mining area is mainly exposed, the upper Cambrian Lou Shan Guan formation (? 2-3l), the Middle Cambrian Gao Tai formation (? 2G) and the lower Cambrian deficiency In the formation (? 1q) formation, the lead and zinc minerals are in the limestone strata of the Qingxu formation in the Cambrian system and are controlled by the tectonic lithofacies. The selection of the fluid characteristics and the metallogenic process analysis of the Xiangxi Li Mei lead-zinc deposit, as the title of the dissertation, has important geological scientific research significance and geological prospecting reference value. Relying on the Huayuan rectification exploration in Zhangjiajie, Xiangxi On the basis of field geological survey and structural survey, the comprehensive research on identification and test analysis in the field is carried out on the basis of field geological survey and structural survey. The main research targets are the structure and rock characteristics of the mining area. The research project report and the dissertation are submitted on time. The main achievements are as follows: 1. Li Meiqian The mineralization process of zinc deposits is divided into four stages: according to the different types of mineralization and distribution characteristics observed in the field, the detailed ore structure structure, mineral crystallization state and combination characteristics under the microscope, the mineralization process of the deposit is divided into the following four stages. It is mainly sparse and disseminated ore, formed in the early stage. The sphalerite galena along the fissure and pore metasomatism filling stage: the mineralization is strong and the metallogenic material is concentrated. The metal minerals are mainly sphalerite, followed by galena and pyrite. The gangue minerals are mainly calcite, second is barite, fluorite and so on. Ore formed in this stage. The main metallogenic phase, speckled ore, formed in the main metallogenic stage. The galena calcite filling stage: the mineral assemblage of the metallogenic stage is simple, the metal minerals are only galena and a small amount of sphalerite, and the gangue minerals are only calcite. .2. has completed the analysis of the fluid characteristics of the Li Meicheng ore stage: the fluid inclusions in a certain number of samples were developed in this sample, mainly as inclusions of gas-liquid two phases. Sphalerite galena along fissures, pore metasomatism and filling stage, and the salinity of gas-liquid inclusions in 1.1%-23.1%Na Cleqv., the homogenization temperature is 78-342 C, the density of fluid fluid is 0.70-1.14g/cm3, and the metallogenic pressure is between 194.30-960.19bar. galena and calcite filling stage. The salinity of the gas-liquid inclusions is between 1.4%-23.1%Na Cleqv., the homogeneous temperature is at 68-259, the density of the fluid body of the ore-forming fluid is 0.88-1.15g/cm3, and the metallogenic pressure is in 190.99-7. The 27.13bar. hydrothermal calcite veins are in the stage of fracture invasion. The salinity of the gas-liquid inclusions is between 3.71%-23.18%Na Cleqv., the homogeneous temperature is between 76-227 and 0.91-1.12g/cm3, and the density of the fluid fluid is 0.91-1.12g/cm3. The metallogenic pressure is in the 199.46-637.29bar. inclusions study. The homogeneous temperature of fluid inclusions in the Li Meikuang bed mineralization process has been reduced. The change of the average salinity is weak, and the peak salinity of its salinity is in the 21.0%-23.0% interval.3. points out the sedimentary environment characteristics of the Li Mei MVT type lead zinc mine area: the carbonate rocks in the Qingxu hole group and the high platform group in the periphery of the Li Mei lead-zinc mining area are the research objects, and the major rock mass and trace element geochemical analysis are mainly used to obtain the Li Mei lead and zinc. The sedimentary characteristics of carbonate rocks in the Qingxu hole period and the high stage of the mining area show the trend of the gradual retreat of the sea water. In the Qingxu cave period - high stage, the carbonate deposits are limited by the terrigenous clastic and diagenesis, the paleoceanic environment is the oxidizing environment, the ancient sea water is warm water environment, the paleo climate changes from damp to drought, and it is also the change of the paleo climate. In this sea water environment, a large number of algal organisms are propagated and formed into algal limestone, and the main ore bearing rock.4. has compiled the contour map of the ore body of the Huayuan ore field. The metallogenic process of the Li Mei lead-zinc deposit is analyzed. The characteristics of the deep deposits and the understanding of the tectonic evolution mineralization are deepened. The host rock of the Li Mei type MVT type lead-zinc deposit is dominated by algal limestone, which is produced in the north-east to north to North East to gentle fold and fault tectonic zone formed by the snow peak period - Caledonian tectonic movement. Lead zinc and other elements enrich and mineralized the deposits.

【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.4

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