青海格尔木卡尔却卡铜矿床地质特征及矿化富集规律研究

发布时间：2018-04-29 09:20

  本文选题：矿床地质特征 + 矿床成因　； 参考：《吉林大学》2015年硕士论文

【摘要】：卡尔却卡铜矿位于青海省格尔木市乌图美仁乡，大地构造位置属于东昆仑造山带西段，其内发育一系列金属矿床，本文主要对A（野拉赛）、B（索拉吉尔）两个矿段进行研究。 区内出露的地层主要为滩间山群。区内侵入体大面积分布，主要岩性为似斑状黑云母二长花岗岩和黑云母花岗闪长岩。岩相学、年代学和岩石地球化学等研究表明：似斑状黑云母二长花岗岩形成于早石炭世，并且岩体形成于同碰撞环境，古特提斯洋已经闭合，已经进入陆内造山阶段；黑云母花岗闪长岩形成于中三叠世，并且岩体形成的构造背景为俯冲环境。区内断裂构造较发育，主要有北西西向断裂和北东向断裂两组，其中北西西向断裂组是区内的主干构造，多金属矿体主要赋存于该组断裂及其次一级构造中。 A矿段共圈出蚀变带3条，产于似斑状黑云母二长花岗岩体中。蚀变带由破碎的似斑状黑云母二长花岗岩和后期的花岗细晶岩、石英脉组成，总体走向北西-南东向，倾向北东，倾角65°-80°之间。矿石类型以破碎带蚀变岩型为主，也发育石英脉型。围岩蚀变类型有高岭土化、绢云母化、钾化、硅化和绿泥石化等。B矿段共圈出矽卡岩带4条（其中地表3条、深部1条），均产于花岗闪长岩、似斑状黑云母二长花岗岩与滩间山群地层的接触部位，总体走向北西西向，倾角20°-85°之间。矿石类型主要有含黝铜矿黄铜矿斑铜矿矿石、含黄铜辉钼矿矿石、自然铜矽卡岩矿石和孔雀石化（含黄铜）磁铁矿矿石四种类型(据勘探资料)。矽卡岩带内蚀变主要为矽卡岩化、透辉石化、绿泥石化、绿帘石化、硅化等。 实验结果显示，卡尔却卡A矿段成矿流体经历了由高盐度到低盐度的演化过程；气液两相包裹体温度峰值区间为260~340℃，含CO2三相包裹体温度峰值区间为340~360℃，成矿流体具有中高温特征；成矿压力范围为51~97MPa，成矿深度集中于5.70~8.12km。成矿物质中，硫以深源岩浆硫为主，并有少量围岩硫参与，，也可能是成矿流体运移的过程中从地壳物质汲取各种成因硫。成矿流体来源以岩浆水为主，后期叠加有大气降水等其他流体。综合分析认为，卡尔却卡A矿段矿床成因类型为受线性断裂构造控制的中高温热液脉型铜矿床，B矿段矿床成因类型为典型的矽卡岩型铜矿床。 在综合以上研究成果的基础上对卡尔却卡铜矿的矿化富集规律进行归纳总结，A矿段矿体严格受NWW向断裂控制，矿化与硅化关系最密切，与典型的斑岩型铜矿有严格区别；B矿段矿体受矽卡岩接触带和NWW向断裂联合控制，并且当地层与矽卡岩接触带大角度斜交时最易产生富矿体。
[Abstract]:Kartsoka copper deposit is located in Utumeren Township, Geermu City, Qinghai Province. The geotectonic position belongs to the western section of the East Kunlun orogenic belt, in which a series of metal deposits are developed. The outcropping strata in the area are mainly inter-beach mountain groups. In this area, the intrusions are distributed in large areas, and the main lithology is porphyry biotite monzogranite and biotite granodiorite. The petrographic, chronological and petrogeochemical studies indicate that the porphyry biotite binomorphic granites were formed in the early Carboniferous and formed in the same collision environment. The PaleoTethys ocean has been closed and has entered the intracontinental orogenic stage. Biotite granodiorite was formed in the Middle Triassic and formed in a subduction environment. There are two groups of faults in this area: NW-trending fault and NE-trending fault. The NW-trending fault group is the main structure in the area, and the polymetallic ore body mainly occurs in this group fault and its sub-primary structure. There are 3 alteration zones in a ore section, which are found in porphyry biotite monzonitic granites. The altered zone is composed of a broken porphyry biotite monzonitic granite and late granitic fine-grained rocks, quartz veins, with a general strike from NW to SE, trending to NW, with a dip angle of 65 掳-80 掳. The ore type is mainly altered rock type in broken zone, and quartz vein type is also developed. The alteration types of surrounding rock are kaolin, sericite, kalitization, silicification and green-mud fossilization. There are 4 skarn belts (3 on the surface and 1 in the deep, all occurring in granodiorite). The contact position between the porphyry biotite monzonitic granite and the strata of the Tanjianshan Group is generally NW trending, with a dip angle of 20 掳-85 掳. There are mainly four types of ore including chalcopyrite porphyrite, copper molybdenum ore, natural copper skarn ore and peacock magnetite ore (according to exploration data). The internal alteration of skarn zone is mainly skarn, diopside, green mud, green curtain, silicification and so on. The experimental results show that the ore-forming fluid in Kartsoka A ore section has undergone the evolution from high salinity to low salinity, the peak temperature range of gas-liquid two-phase inclusions is 260 ~ 340 鈩

本文编号：1819326