阿合奇县阿沙哇义金矿床岩石破碎—蚀变特征与成矿关系研究

发布时间：2018-04-05 09:33

本文选题：金矿床　切入点：破碎蚀变　出处：《新疆大学》2017年硕士论文

【摘要】：阿沙哇义金矿床地处新疆柯尔克孜族自治州阿合奇县境内,大地构造属于塔里木板块北缘活动带的南天山成矿带,其北南东侧为有一条区域大断裂——卡拉铁克大断裂,呈北东走向。阿沙哇义金矿床赋矿地层主要是上石炭系喀拉治尔加组下段的变余砂岩和千枚岩岩层或互层。矿区内破碎蚀变带发育,矿体主要以10°交角与地层斜交产出于破碎带内,产出有硅化、绢云母化、黄铁矿化、褐铁矿化、毒砂化等常见金矿床蚀变类型。蚀变由中心向两侧分为黄铁绢英岩化带、石英绢云母带,绢云岩化带。成矿过程分为变质热液期和表生氧化期,其中变质热液期又分为三个成矿阶段,分别包括石英-黄铁矿、多金属硫化物-石英、石英-碳酸盐阶段,并与早、中、晚三个围岩蚀变阶段相对应。硅化、黄铁绢云英岩化与Au矿化呈正相关,而且关系紧密。采自近矿或矿体中石英脉的流体包裹体分为:水溶液型、富CO2型、H2O-CO2型、含子矿物的包裹体,其中含子矿物的包裹体极少。水溶液型包裹体均一温度在170~220℃和240~340℃两个区间范围,平均温度集中在200℃和280℃,盐度0~10wt%NaCleq,密度0.768~0.817g/cm3,压力变化0.39~1.19×10-7Pa之间;含CO2型的包裹体完全均一温度多数集中在200℃~320℃,部分均一温度在18.5~25.1℃,盐度在2.62~8.55wt%NaCleq,初溶温度为-56.8~-61.9℃,含CH4或N2。δ18OV-SMOW为18.1‰~19.5‰,δ18O水值主要集中在1.5‰~4.8‰之间,δDPDB为-81.3‰~-73.4‰。区域化探元素异常显示该区的变余砂岩和千枚岩中Au的丰度值比区域平均值高,δ34S值17.8‰~19.2‰。通过对地层层位、构造活动、蚀变特征与矿化关系、流体包裹体测温等研究并结合同位素示踪,说明了阿沙哇义金矿床主要受区域大断裂的次级断裂控制,矿体发育在破碎带中,成矿热液属低温、低压、富CO2的热液,主要来自沉积建造水,并混入少量大气降水,成矿物质来自地层,证明了阿沙哇义金矿床属于破碎-蚀变岩型金矿床。总结了断层破碎带、围岩硅化、黄铁绢云英岩化蚀变、变余砂岩与绢云千枚岩互层或接触部位破碎带、金砷锑元素异常区等找矿标志,并建立了找矿模型。
[Abstract]:Ashawayi gold justice bed is located in the territory of Akeqi County, Xinjiang Kirgiz Autonomous, belonging to the northern margin active tectonic belt of the Tarim plate of the South Tianshan metallogenic belt, the North South East is a regional fault - Kalatieke fault, was the north east direction. Asawahyi Kim deposits stratum is mainly in the Kalazhierjia group section metaclastics and phyllite interbedded strata or alteration zone. In the mining area development, mainly in the 10 degree angle of orebody formation and skew produced in the fracture zone, output silicification, sericitization, pyritization, limonite, arsenopyrite and other common alteration type gold deposit alteration. From the center to the two sides divided into beresitization zone, quartz sericite zone, sericite alteration belt. The mineralization process divided into metamorphic hydrothermal stage and supergene oxidation stage, the metamorphic hydrothermal period is divided into three mineralization stages, including quartz Pyrite and polymetallic sulfide quartz, quartz carbonate stage, and early, in late three, rock alteration stages. Silicification, greisenization and Au Huang Tiejuan were related closely. The mineralization, and the recovery of fluid inclusions from near ore or ore quartz veins in the water solution type is divided into: rich, CO2 type, H2O-CO2 type, inclusions containing Daughter Minerals, including inclusions containing daughter minerals are rare. The water solution type inclusions in 170~220 C and C 240~340 two range, the average temperature in 200 degrees and 280 degrees, the salinity density of 0.768~0.817g/cm3, 0~10wt%NaCleq, 0.39~1.19 * 10-7Pa between the pressure change CO2; inclusion type most complete homogenization temperature at 200 DEG ~320 DEG, homogeneous temperature at 18.5~25.1 Deg. C, salinity in 2.62~8.55wt%NaCleq, initial solution temperature of -56.8~-61.9, containing CH4 or N2. 8 18OV-SMOW 18.1 per thousand ~19.5%, 18O value of main water. From 1.5 to% ~4.8%, -81.3% ~-73.4% ~ DPDB. Regional geochemical element anomaly in this area shows the abundance of metaclastics and Au in phyllite in the average value is higher than the regional 34S values of 17.8 per thousand ~19.2 per thousand. The strata, tectonic activity, alteration and mineralization characteristics. Measurement of fluid inclusions and other research combined with isotope tracer, the control of secondary fracture ashawayi gold justice bed mainly by regional faults, ore bodies developed in the fractured zone of the ore-forming fluid is a low temperature, low pressure, hot liquid rich CO2, mainly from sedimentary formation water, and mixed with a small amount of precipitation, the ore-forming material from the formation, proved ashawayi gold justice bed belongs to the broken altered rock type gold deposit. Summarizes the fault fracture zone, Huang Tiejuan rock silicification, greisenization alteration, metaclastics and sericite phyllite interbedded or contact area of fracture zone, gold and arsenic antimony anomaly area etc. The ore prospecting marks are found and the ore finding model is set up.

【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.51

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