甘肃北山地区460金矿矿床地质及成矿流体研究
发布时间：2018-12-14 02:42
【摘要】：460金矿床地处西伯利亚板块与哈萨克斯坦板块碰撞形成的板块缝合线上,紧邻红石山-黑鹰山地体。矿区出露地层主要为下石炭统的白山组中酸性变质火山岩及碎屑沉积岩建造;矿区构造以近NW向断裂为主,是矿区的主要控矿容矿构造;矿区岩浆岩主要为花岗闪长岩,多呈岩基、岩株状产出。矿体主要赋存于花岗闪长岩的断裂或节理裂隙中,受近EW向和NE向断裂控制;矿石以石英脉型为主,矿石矿物主要包括黄铁矿、黄铜矿、辉铜矿等,脉石矿物主要有石英、长石、绿泥石、绢云母等,金多以碲化物的形式存在,主要有斜方碲金矿和针碲金银矿;矿石结构主要有半自形-他形晶粒状结构、填隙结构、交代网状结构等。矿石的构造主要为细脉-网脉状,另有条带状、团块状等。围岩蚀变以绢云母化、绿泥石化、绿帘石化、碳酸盐化等低温蚀变为主;成矿阶段从早到晚划分为石英-黄铁矿阶段、石英-多金属硫化物阶段和石英-碳酸盐阶段。各成矿阶段脉石矿物(石英、方解石)中均发育有流体包裹体。包裹体的类型包括富液相Na Cl-H2O型包裹体(W型)和含子矿物流体包裹体(S型)。以椭圆状、似圆状和不规则状居多,次为负晶形等。包裹体大小多数集中在5~15μm之间,且包裹体的气液相比例变化于10%~30%。从早到晚流体包裹体完全均一温度分别为202.4~348.3℃,135.9~282.1℃和104.8~165.8℃,盐度分别为1.4%~10.98%Na Cl.eqv,2.07%~13.51%Na Cl.eqv和0.35%~8.14%Na Cl.eqv,成矿流体总体显示低温、低盐度为特征。成矿环境属浅成环境。H、O同位素表明,成矿流体并非单一来源,具有岩浆水与大气降水混合的特征。流体的混合作用是Au、Te等成矿元素沉淀的主要原因。本文通过锆石U-Pb年龄获得460岩体的成岩年龄在340~341Ma。根据区域上金矿床的形成年龄与岩浆侵入活动时间具有明显的耦合关系,结合本文矿床地质和流体包裹体特征的研究,460金矿床属于富碲的浅成低温热液型矿床,成矿年龄为海西中、晚期。
[Abstract]:The gold deposit is located on the suture line of plate formed by collision between Siberian plate and Kazakstan plate, adjacent to Hongshi Mountain and Black Eagle Mountain body. The exposed strata of the mining area are mainly the formation of intermediate acid metamorphic volcanic rocks and clastic sedimentary rocks of Baishan formation of Lower Carboniferous, the structure of the mining area is dominated by the near NW fault, which is the main ore-controlling structure of the mining area. The magmatic rocks are mainly granodiorite, most of them are rock base, and they occur in the form of rock plants. The orebody mainly occurs in the faults or joints of granodiorite and is controlled by the near EW and NE faults. The ore is mainly of quartz vein type. The ore minerals mainly include pyrite, chalcopyrite, etc. The gangue minerals are mainly quartz, feldspar, chlorite, sericite, etc. The gold is mostly in the form of telluride. There are mainly diagonal tellurium gold deposits and goethurium gold silver ores. The ore structure mainly consists of semi-automorphic-allotropic grain structure, interstitial structure, metasomorphic network structure and so on. The structure of the ore is mainly vein-net vein, other banded, lumpy, and so on. The main alteration of surrounding rock is sericite, green mud, green curtain, carbonization, etc. The metallogenic stage is divided into quartz pyrite stage, quartz polymetallic sulfide stage and quartz carbonate stage from early to late. Fluid inclusions are found in gangue minerals (quartz, calcite) in all metallogenic stages. The types of inclusions include liquid rich Na Cl-H2O inclusions (W type) and submineral fluid inclusions (S type). Ellipsoid, like round and irregular shape is the majority, the second is negative crystal shape and so on. Most of the inclusions are concentrated in the range of 5 ~ 15 渭 m, and the gas-liquid ratio of inclusions varies from 10 to 30. The complete homogenization temperatures of fluid inclusions from early to late were 202.4U 348.3 鈩，
本文编号：2377760
[Abstract]:The gold deposit is located on the suture line of plate formed by collision between Siberian plate and Kazakstan plate, adjacent to Hongshi Mountain and Black Eagle Mountain body. The exposed strata of the mining area are mainly the formation of intermediate acid metamorphic volcanic rocks and clastic sedimentary rocks of Baishan formation of Lower Carboniferous, the structure of the mining area is dominated by the near NW fault, which is the main ore-controlling structure of the mining area. The magmatic rocks are mainly granodiorite, most of them are rock base, and they occur in the form of rock plants. The orebody mainly occurs in the faults or joints of granodiorite and is controlled by the near EW and NE faults. The ore is mainly of quartz vein type. The ore minerals mainly include pyrite, chalcopyrite, etc. The gangue minerals are mainly quartz, feldspar, chlorite, sericite, etc. The gold is mostly in the form of telluride. There are mainly diagonal tellurium gold deposits and goethurium gold silver ores. The ore structure mainly consists of semi-automorphic-allotropic grain structure, interstitial structure, metasomorphic network structure and so on. The structure of the ore is mainly vein-net vein, other banded, lumpy, and so on. The main alteration of surrounding rock is sericite, green mud, green curtain, carbonization, etc. The metallogenic stage is divided into quartz pyrite stage, quartz polymetallic sulfide stage and quartz carbonate stage from early to late. Fluid inclusions are found in gangue minerals (quartz, calcite) in all metallogenic stages. The types of inclusions include liquid rich Na Cl-H2O inclusions (W type) and submineral fluid inclusions (S type). Ellipsoid, like round and irregular shape is the majority, the second is negative crystal shape and so on. Most of the inclusions are concentrated in the range of 5 ~ 15 渭 m, and the gas-liquid ratio of inclusions varies from 10 to 30. The complete homogenization temperatures of fluid inclusions from early to late were 202.4U 348.3 鈩，
本文编号：2377760
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