江苏溧水马占山铜矿床成因及找矿勘查研究

发布时间：2018-05-10 05:18

本文选题：矿床地质 + 矿石结构构造　；参考：《南京大学》2015年硕士论文

【摘要】：马占山铜矿位于扬子地台下扬子地区溧水火山盆地东南缘,是该区近年来刚发现的小型铜多金属矿床。该矿床地质地球化学特征及成因研究十分薄弱,制约了区内的找矿勘查工作。本文在详细的野外工作基础上,结合室内对矿石成分和矿石组构的详细观察和鉴定,再运用流体包裹体地球化学理论和方法,确定矿床成因类型,在此基础上,利用物化探手段,圈定找矿靶区,并经钻探工程验证,取得良好的经济效益。矿床赋存于上侏罗统大王山组粗安岩、含角砾粗安岩、粗安质含角砾凝灰熔岩陆相火山岩中,矿体呈脉状、透镜状明显受近东西向和北东向构造断裂控制。矿石机构构造研究表明矿石矿物主要为黄铜矿和黄铁矿,次为斑铜矿和赤铁矿,少量方铅矿和闪锌矿;脉石矿物主要有石英、重晶石和方解石等;矿石构造以脉状、细脉状和网脉状构造为主,次为浸染状和团斑状;矿石结构以呈自形晶粒状—他形晶粒状结构、放射状结构和充填结构为主,次为交代结构。与铜矿化有关的石英脉及重晶石脉中流体包裹体的研究结果表明均为气液两相包裹体,成矿流体主要为中低温、低盐度的NaCl-H2O体系流体,流体的演化趋势反映出岩浆热液与大气降水混合过程。矿床地质地球化学特征,反映出其属于浅成低温热液矿床。物化探工作揭示了在本区四条勘查线存在与铜(铅锌)矿化有关的物化探异常标志,经钻探工程验证,均成功见矿,表明本区具有良好的找矿前景。
[Abstract]:The Mazhanshan copper deposit is located in the southeast margin of the Lishui volcanic basin in the Yangzi area under the Yangtze platform. It is a small copper polymetallic deposit which has just been discovered in this area in recent years. The geological and geochemical characteristics and genesis of the deposit are very weak, which restricts the prospecting work in this area. On the basis of detailed field work, combined with the detailed observation and identification of ore composition and ore fabric in laboratory, and using the geochemical theory and method of fluid inclusions, the genetic types of ore deposits are determined. By means of geophysical and geochemical exploration, the prospecting target area is delineated, and the good economic benefit is obtained by drilling engineering. The deposit is located in the upper Jurassic Dawangshan formation, which contains breccia, tuff andesite. The orebody is vein-like in continental volcanic rock, and the lenticular is obviously controlled by the near-EW and NE-trending structural faults. The study of ore structure shows that the main ore minerals are chalcopyrite and pyrite, the secondary ore is porphyrite and hematite, a small amount of galena and sphalerite, the gangue minerals are mainly quartz, barite and calcite, etc. The main structures are vein-like and net-veined, the secondary is disseminated and agglomerate, the ore structure is self-shaped granular-allohedral structure, the radial structure and filling structure are dominant, and the secondary structure is metasomatism. The results of study on fluid inclusions in quartz vein and barite vein related to copper mineralization indicate that they are gas-liquid two-phase inclusions, and ore-forming fluids are mainly NaCl-H2O fluids with medium and low temperature and low salinity. The trend of fluid evolution reflects the mixing process of magmatic hydrothermal and atmospheric precipitation. The geological and geochemical characteristics of the deposit reflect that it belongs to the epithermal hydrothermal deposit. Geophysical and geochemical exploration work reveals that there are geophysical and geochemical anomalies related to copper (lead and zinc) mineralization in four exploration lines in this area. All of them have been successfully discovered by drilling engineering, which indicates that this area has a good prospecting prospect.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.41

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