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1.
哈图金矿蚀变岩型矿体特征及金赋存状态研究 总被引：1，自引：0，他引：1
哈图金矿由石英脉型和蚀变岩型矿体组成,蚀变岩型矿体遭受了强烈黄铁矿化、毒砂化、碳酸盐化、硅化和绢云母化蚀变.成矿作用划分5个阶段:钠长石-石英阶段(I)、黄铁矿-碳酸盐-石英阶段(II)、黝铜矿-黄铜矿-自然金阶段(III)、毒砂-碳酸盐-绢云母阶段(IV)和方解石-石英阶段(V).其中,II—IV阶段是主要金成矿阶段.哈图金矿含金矿物主要为自然金,平均成色912.自然金呈裂隙金、包裹金、粒间金形式嵌布在黄铁矿和毒砂中.当载金矿物为黄铁矿时,自然金与黝铜矿-黄铜矿-闪锌矿关系密切;当载金矿物为毒砂时,自然金与黄铁矿-黄铜矿关系密切. 相似文献
2.
《地质科技情报》1991,(2)
早川与释迦坑矿床的铜铅锌矿化作用特征,集中表现在单位矿脉的构造、矿物组合、矿化阶段以及矿脉中石英和母岩氧同位素组成等方面.早川与释迦坑的矿床中,存在着黄铜矿—黄铁矿—黝铜了—方铅矿—伴有闪锌矿的石英脉(铜铅锌石英脉)以及方铅矿—伴有闪锌矿的石英脉(铅锌石英脉.铜铅锌石英脉较铅锌石英脉更早期形成.铜铅锌石英脉的矿物组合为黄铜矿、黄铁矿、黝铜矿—砷黝铜矿、方铅矿、闪锌矿、硫砷铜矿、车轮矿、板硫锑铅矿、碲银矿、黄锡锌矿、砷等轴硫钒铜矿、Cu-Fe-Zn-Sn-S系矿物、硫碲铋铅矿、硫铜铋铅矿、石英以及磷灰石.铅锌石英脉的矿物组合为方铅矿、闪锌矿、黄铁矿、黄铜矿、黝铜矿、银金矿及石英.随着矿化作用早期向晚期过渡,闪锌矿中的FeS含量有所减低.黝铜矿—砷黝铜矿的单一颗粒中,Sb与As之间的化学组成出现明显的非均质性. 相似文献
3.
《矿物岩石地球化学通报》2016,(5)
为查明黑龙江省大新屯锑金矿床的成因、为找矿工作提供一些理论依据,对矿床中金、矿物开展了电子探针、X射线粉晶衍射和流体包裹体测温分析测试。结果表明,矿床中含金矿物以自然金为主,可见极少的针碲金银矿和碲金银矿;研究发现了2种新的Au-Sb化合物(Au2Sb3和Au0.9Sb0.1,疑似新矿物),其粒度极小(2~4μm)、含量极低、与自然金共生。锑矿化晚于金矿化,矿床中的含锑矿物以辉锑矿为主,有微量的硫锑铅银矿、块硫锑铜矿、硫锑铅矿、黝锑银矿。金在后期形成的含锑硫化物中含量较低。研究表明,成矿过程分为石英-金属硫化物阶段、石英-黄铁矿-金矿化阶段、石英-辉锑矿矿化阶段和石英-碳酸岩阶段4个矿化阶段。 相似文献
4.
湘东北杨山庄金矿床流体成矿机制 总被引：3，自引：3，他引：0
杨山庄金矿床位于江南造山带中部,矿体严格受NW-NWW向断裂控制,赋存于新元古代浅变质的绢云母板岩和粉砂质板岩中,成矿期分为三个阶段:石英-毒砂-黄铁矿(少量)-自然金-白钨矿-白云石-白云母(阶段Ⅰ)、石英-毒砂-黄铁矿-自然金-黄铜矿-方铅矿-闪锌矿-绢云母(阶段Ⅱ)和石英-方解石(阶段Ⅲ)。成矿Ⅰ、Ⅱ阶段流体包裹体以两相水溶液包裹体为主,含有少量的气相包裹体和含CO_2的三相包裹体,气相包裹体成分为CH_4-N_2-CO_2、N_2-CO_2和N_2。成矿温度集中在240~320℃,盐度集中在7%~9%Na Cleqv,成矿流体为中-低温、中低盐度H_2O-Na Cl-CO_2体系。在成矿Ⅰ、Ⅱ阶段,成矿流体与围岩发生交代反应,流体发生相分离,使液相CO_2含量降低,引起Au(HS)~(2-)溶解度降低,导致金发生沉淀。 相似文献
5.
6.
《吉林大学学报(地球科学版)》2015,(Z1)
<正>德兴斑岩铜矿为中国东部最大的斑岩铜矿。该矿床由三个矿体组成,从大到小分别是铜厂、富家坞和朱砂红矿体。本次研究主要针对铜厂和富家坞矿体进行。围岩蚀变主要为早期的钾化蚀变,成矿期的绿泥石-石英-绢云母化蚀变,以及晚期的石英-黄铁矿-碳酸盐化蚀变。野外观察和显微岩相学鉴定发现,该矿床的形成与高氧逸度环境有密切关系,矿化阶段可见大量磁铁矿-镜铁矿(赤铁矿的变形)等铁氧化物矿物与硫化物共生。部分矿化阶段的黄铁矿具有环带结构:黄铁矿中的共生黄铜矿-镜铁矿矿物包裹体环带。锆石 相似文献
7.
《地球化学》2016,(6)
红海VMS铜锌矿床位于新疆东天山大南湖-头苏泉岛弧带的卡拉塔格地区,矿床上部发育似层状块状硫化物矿体,下部为不整合的脉状-网脉状矿体,块状矿体上盘火山岩盖层中也发育少量铜矿化。本文在前人工作基础上,根据矿物交代次序、脉体穿插关系和矿物共生组合类型,精细划分了矿床的蚀变分带和成矿期次。矿床(含盖层)从浅到深依次发育绿泥石-钠长石-绢云母-碳酸盐化、绿帘石-绿泥石-钠长石-绢云母-碳酸盐化、石英-绢云母-黄铁矿化、块状硫化物矿体、绿泥石-黄铁矿±绢云母化和绿泥石-石英-绢云母化。红海矿床成矿过程可分为VMS成矿期、后期热液叠加期和表生期,其中VMS成矿期可细分为黄铁矿阶段、黄铜矿-闪锌矿阶段和重晶石阶段,后期热液叠加期可细分为钠长石化阶段、绿泥石-绿帘石阶段和石英-碳酸盐阶段。主矿化期及蚀变特征与典型VMS矿床类似,但同时还表现出许多海底交代作用的特征。后期热液在矿体上盘火山岩中所产生的绿帘石化、绿泥石化和绿帘石-石英-黄铜矿-斑铜矿脉、石英-碳酸盐脉等蚀变和矿化,与斑岩矿化系统的青磐岩化类似,表明红海矿床后期可能受到斑岩系统的叠加,矿区具有斑岩铜矿床的找矿潜力。 相似文献
8.
胶东金成矿省位于胶辽隆起,中朝地台东部,基底岩石是太古宙和元古宙变质岩。中生代沉积及火山盖层产于拉伸盆地中,侵入岩主要是中生代花岗岩类,基底杂岩中有东西向复背斜及大规模的中生代北东—南西向和北北东—南南西向的断裂带。金矿化与花岗岩中或花岗岩与基底岩石接触带中的中生代断层及其派生断层有关。矿化类型是石英脉型和蚀变岩型。围岩蚀变在矿带周围非常发育。蚀变矿物有石英,绢云母(和铬云母)、黄铁矿、方解石、绿泥石、赤铁矿、金红石、石墨。在所有的矿床中,矿石的矿物组合都是一致的。矿物组合包括:黄铁矿、黄铜矿、闪锌矿、毒砂、方铅矿、自然金、银金矿、磁黄铁矿、碲银矿、砷金银矿等等。华南和华北陆块在中生代碰撞和俯冲、造成了中生代花岗岩体的侵入。花岗岩浆来自地壳部分熔融。金从基底岩石中活化迁移,并且通过与这些作用有关的高温热液沉积在断裂带中。 相似文献
9.
新疆包古图金矿四矿区L7号脉中的特殊矿物组合及其成矿意义 总被引：3，自引：3，他引：0
包古图金矿四矿区L7号脉由浅部的自然砷-石英脉型矿石和深部的辉锑矿-石英脉型矿石组成。矿脉中含罕见的As、Sb矿物,如paakkonenite（Sb2AsS2）、自然砷、自然锑、方锑金矿、硫锑金银矿（Au3Ag4Sb10S12）等。热液过程划分为5个阶段：黄铁矿-毒砂阶段（Ⅰ）,围岩中形成大量的毒砂和黄铁矿并伴随较强硅化;粗粒石英阶段（Ⅱ）,形成沿围岩壁或围岩角砾的梳状石英;Au-As-Sb矿化阶段（Ⅲ）,形成辉锑矿-自然锑-自然砷-paakkonenite-银金矿-自然金-方锑金矿-硫锑金银矿-辉锑银矿-银锌黝铜矿-斜方砷铁矿-硫铜锑矿-石英;晚期Sb矿化阶段（Ⅳ）,形成与粒状方解石共生的辉锑矿、自然锑和paakkonenite;方解石阶段（Ⅴ）,形成穿切矿体和围岩的方解石（-石英）细脉。辉锑矿和斜方砷铁矿交代毒砂,自然金、方锑金矿、paakkonenite和自然砷交代辉锑矿。辉锑矿的结晶主要受温度和还原S含量的控制,自然砷、自然锑的结晶主要受氧逸度和温度控制。As、Sb分别以自然砷、辉锑矿和自然锑形式存在,同时消耗大量H2S,流体进入张性空间后也释放H2S,导致硫逸度急剧降低,含Au络合物失稳而成矿。 相似文献
10.
桦树沟铜矿床位于北祁连加里东造山带西段。铜矿体赋存于镜铁山BIF型铁矿床桦树沟矿区FeⅤ矿体下盘,矿体受断裂构造控制,矿化岩石主要为铁碧玉岩、石英绢云母千枚岩和碳质千枚岩,围岩蚀变可见硅化、碳酸盐化、绢云母化和绿泥石化。文章对块状铜矿石(富铜矿体)和脉状铜矿石(千枚岩型铜矿体)进行了野外地质特征、矿物学和硫同位素对比研究。富铜矿体与地层产状基本一致,块状矿石矿物组合为黄铜矿+少量黄铁矿+石英+碳酸盐矿物+重晶石,黄铜矿低S、Cu,高Fe。脉状矿石主要表现为石英-碳酸盐-硫化物脉沿千枚理或裂隙产出,矿石矿物组合为黄铜矿+黄铁矿+黝铜矿+镜铁矿+石英+碳酸盐矿物+绢云母+绿泥石,黄铜矿低S高Fe。块状铜矿石中黄铜矿的δ34S变化范围为15.6‰~17.4‰,暗示硫主要来自同期海水。脉状矿石中硫化物的δ34S值低于块状矿石中黄铜矿的δ34S值,黄铜矿、黄铁矿的δ34S值变化范围分别为13.2‰~16.2‰和9.3‰~13.4‰,暗示硫可能主要来自受还原的硫化物和硫酸盐矿物。以上研究表明块状铜矿石和脉状铜矿石可能为不同热事件的产物,结合前人研究成果,笔者认为桦树沟铜矿床为海底喷流沉积叠加后期热液改造成因。绿泥石温度计指示后期热液成矿温度为222℃左右。 相似文献
11.
Gold Mineralization of the Gatsuurt Deposit in the North Khentei Gold Belt,Central Northern Mongolia
Mineral assemblages, chemical compositions of ore minerals, wall rock alteration and fluid inclusions of the Gatsuurt gold deposit in the North Khentei gold belt of Mongolia were investigated to characterize the gold mineralization, and to clarify the genetic processes of the ore minerals. The gold mineralization of the deposit occurs in separate Central and Main zones, and is characterized by three ore types: (i) low‐grade disseminated and stockwork ores; (ii) moderate‐grade quartz vein ores; and (iii) high‐grade silicified ores, with average Au contents of approximately 1, 3 and 5 g t?1 Au, respectively. The Au‐rich quartz vein and silicified ore mineralization is surrounded by, or is included within, the disseminated and stockwork Au‐mineralization region. The main ore minerals are pyrite (pyrite‐I and pyrite‐II) and arsenopyrite (arsenopyrite‐I and arsenopyrite‐II). Moderate amounts of galena, tetrahedrite‐tennantite, sphalerite and chalcopyrite, and minor jamesonite, bournonite, boulangerite, geocronite, scheelite, geerite, native gold and zircon are associated. Abundances and grain sizes of the ore minerals are variable in ores with different host rocks. Small grains of native gold occur as fillings or at grain boundaries of pyrite, arsenopyrite, sphalerite, galena and tetrahedrite in the disseminated and stockwork ores and silicified ores, whereas visible native gold of variable size occurs in the quartz vein ores. The ore mineralization is associated with sericitic and siliceous alteration. The disseminated and stockwork mineralization is composed of four distinct stages characterized by crystallization of (i) pyrite‐I + arsenopyrite‐I, (ii) pyrite‐II + arsenopyrite‐II, (iii) galena + tetrahedrite + sphalerite + chalcopyrite + jamesonite + bournonite + scheelite, and iv) boulangerite + native gold, respectively. In the quartz vein ores, four crystallization stages are also recognized: (i) pyrite‐I, (ii) pyrite‐II + arsenopyrite + galena + Ag‐rich tetrahedrite‐tennantite + sphalerite + chalcopyrite + bournonite, (iii) geocronite + geerite + native gold, and (iv) native gold. Two mineralization stages in the silicified ores are characterized by (i) pyrite + arsenopyrite + tetrahedrite + chalcopyrite, and (ii) galena + sphalerite + native gold. Quartz in the disseminated and stockwork ores of the Main zone contains CO2‐rich, halite‐bearing aqueous fluid inclusions with homogenization temperatures ranging from 194 to 327°C, whereas quartz in the disseminated and stockwork ores of the Central zone contains CO2‐rich and aqueous fluid inclusions with homogenization temperatures ranging from 254 to 355°C. The textures of the ores, the mineral assemblages present, the mineralization sequences and the fluid inclusion data are consistent with orogenic classification for the Gatsuurt deposit. 相似文献
12.
Ore mineralization and wall rock alteration of Crater Mountain gold deposit, Papua New Guinea, were investigated using ore and host rock samples from drill holes for ore and alteration mineralogical study. The host rocks of the deposit are quartz‐feldspar porphyry, feldspar‐hornblende porphyry, andesitic volcanics and pyroclastics, and basaltic‐andesitic tuff. The main ore minerals are pyrite, sphalerite, galena, chalcopyrite and moderate amounts of tetrahedrite, tennantite, pyrrhotite, bornite and enargite. Small amounts of enargite, tetradymite, altaite, heyrovskyite, bismuthinite, bornite, idaite, cubanite, native gold, CuPbS2, an unidentified Bi‐Te‐S mineral and argentopyrite occur as inclusions mainly in pyrite veins and grains. Native gold occurs significantly in the As‐rich pyrite veins in volcanic units, and coexists with Bi‐Te‐S mineral species and rarely with chalcopyrite and cubanite relics. Four mineralization stages were recognized based on the observations of ore textures. Stage I is characterized by quartz‐sericite‐calcite alteration with trace pyrite and chalcopyrite in the monomict diatreme breccias; Stage II is defined by the crystallization of pyrite and by weak quartz‐chlorite‐sericite‐calcite alteration; Stage III is a major ore formation episode where sulfides deposited as disseminated grains and veins that host native gold, and is divided into three sub‐stages; Stage IV is characterized by predominant carbonitization. Gold mineralization occurred in the sub‐stages 2 and 3 in Stage III. The fS2 is considered to have decreased from ～10?2 to 10?14 atm with decreasing temperature of fluid. 相似文献
13.
冀北东坪金矿床深部-外围的构造-蚀变-流体成矿研究 总被引：2，自引：0，他引：2
冀北东坪金矿田是我国首次在碱性杂岩体内发现的金矿床,曾被认为是与碱性岩有关的金矿床。近年来年代学数据表明,东坪-后沟一带金矿的赋矿碱性杂岩体形成于海西期,而成矿却主要发生在燕山期。金矿床严格受构造裂隙控制,构造-蚀变-流体成矿作用显著,钾长石化是最重要的蚀变。由未蚀变岩石向矿体和断裂带中心方向,典型的构造-蚀变-矿化分带依次为:0-原岩(二长岩、正长岩)带,I-微斜长石化带,II硅化绢云母化微斜长石岩带,III碎裂微斜长石岩带,及IV断层泥。从0带到III带,Au含量增加,Ag、Cu、Pb、Zn、Mo也略有增加。东坪金矿构造-蚀变-矿化阶段可分为4个:Ⅰ钾长石-石英脉阶段;Ⅱ黄铁矿-白色石英阶段;Ⅲ多金属硫化物-烟灰色石英脉阶段;Ⅳ晚期碳酸盐阶段。深部中段各阶段脉石英的流体包裹体研究表明, 在I、II、III阶段均发育富CO2包裹体。第Ⅰ阶段钾长石石英脉L-V型包裹体均一温度(Th)为220.3~359℃,盐度1.1%~3.1% NaCleqv;H2O-CO2型包裹体Th在346.5~383.5℃。第Ⅱ阶段黄铁矿白色石英脉中L-V型包裹体Th范围是217.2~372.5℃,盐度在1.1%~5.7% NaCleqv;H2O-CO2型包裹体Th在241.2~396.7℃,盐度为2.2%~6.2% NaCleqv。第Ⅲ阶段的烟灰色石英脉中L-V型包裹体Th范围为158.2~350.5℃,盐度在0.7%~5.5% NaCleqv;H2O-CO2型包裹体Th范围在215.2~378℃之间,盐度范围在3.0%~6.0% NaCleqv。第Ⅳ阶段晚期石英脉L-V型包裹体Th范围为151.2~249.8℃,盐度在0.9%~8.3% NaCleqv。矿区外围转枝莲矿段的II阶段白色石英脉中包裹体的Th范围为220~416.2℃,III阶段烟灰色石英脉的Th范围为195.3~425℃。富金石英脉形成于中高温(＞300℃,可达400℃以上)、中深压力(70~160MPa以上)条件下。其成矿背景、热液蚀变、矿物共生组合及流体性质与典型的造山型金矿有一定的差别,归属于"与侵入岩有关的金矿床"更合理。 相似文献
14.
Elena D. Andreeva Hiroharu Matsueda Victor M. Okrugin Ryohei Takahashi Shuji Ono 《Resource Geology》2013,63(4):337-349
Mineralogic studies of major ore minerals and fluid inclusion analysis in gangue quartz were carried out for the for the two largest veins, the Aginskoe and Surprise, in the Late Miocene Aginskoe Au–Ag–Te deposit in central Kamchatka, Russia. The veins consist of quartz–adularia–calcite gangue, which are hosted by Late Miocene andesitic and basaltic rocks of the Alnei Formation. The major ore minerals in these veins are native gold, altaite, petzite, hessite, calaverite, sphalerite, and chalcopyrite. Minor and trace minerals are pyrite, galena, and acanthine. Primary gold occurs as free grains, inclusions in sulfides, and constituent in tellurides. Secondary gold is present in form of native mustard gold that usually occur in Fe‐hydroxides and accumulates on the decomposed primary Au‐bearing tellurides such as calaverite, krennerite, and sylvanite. K–Ar dating on vein adularia yielded age of mineralization 7.1–6.9 Ma. Mineralization of the deposit is divided into barren massive quartz (stage I), Au–Ag–Te mineralization occurring in quartz‐adularia‐clays banded ore (Stage II), intensive brecciation (Stage III), post‐ore coarse amethyst (Stage IV), carbonate (Stage V), and supergene stages (Stage VI). In the supergene stage various secondary minerals, including rare bilibinskite, bogdanovite, bessmertnovite metallic alloys, secondary gold, and various oxides, formed under intensely oxidized conditions. Despite heavy oxidation of the ores in the deposit, Te and S fugacities are estimated as Stage II tellurides precipitated at the log f Te2 values ?9 and at log fS2 ?13 based on the chemical compositions of hypogene tellurides and sphalerite. Homogenization temperature of fluid inclusions in quartz broadly ranges from 200 to 300°C. Ore texture, fluid inclusions, gangue, and vein mineral assemblages indicate that the Aginskoe deposit is a low‐sulfidation (quartz–adularia–sericite) vein system. 相似文献
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The Qolqoleh gold deposit is located in the northwestern part of the Sanandai‐Sirjan Zone, northwest of Iran. Gold mineralization in the Qolqoleh deposit is almost entirely confined to a series of steeply dipping ductile–brittle shear zones generated during Late Cretaceous–Tertiary continental collision between the Afro‐Arabian and the Iranian microcontinent. The host rocks are Mesozoic volcano‐sedimentary sequences consisting of felsic to mafic metavolcanics, which are metamorphosed to greenschist facies, sericite and chlorite schists. The gold orebodies were found within strong ductile deformation to late brittle deformation. Ore‐controlling structure is NE–SW‐trending oblique thrust with vergence toward south ductile–brittle shear zone. The highly strained host rocks show a combination of mylonitic and cataclastic microstructures, including crystal–plastic deformation and grain size reduction by recrystalization of quartz and mica. The gold orebodies are composed of Au‐bearing highly deformed and altered mylonitic host rocks and cross‐cutting Au‐ and sulfide‐bearing quartz veins. Approximately half of the mineralization is in the form of dissemination in the mylonite and the remainder was clearly emplaced as a result of brittle deformation in quartz–sulfide microfractures, microveins and veins. Only low volumes of gold concentration was introduced during ductile deformation, whereas, during the evident brittle deformation phase, competence contrasts allowed fracturing to focus on the quartz–sericite domain boundaries of the mylonitic foliation, thus permitting the introduction of auriferous fluid to create disseminated and cross‐cutting Au‐quartz veins. According to mineral assemblages and alteration intensity, hydrothermal alteration could be divided into three zones: silicification and sulfidation zone (major ore body); sericite and carbonate alteration zone; and sericite–chlorite alteration zone that may be taken to imply wall‐rock interaction with near neutral fluids (pH 5–6). Silicified and sulfide alteration zone is observed in the inner parts of alteration zones. High gold grades belong to silicified highly deformed mylonitic and ultramylonitic domains and silicified sulfide‐bearing microveins. Based on paragenetic relationships, three main stages of mineralization are recognized in the Qolqoleh gold deposit. Stage I encompasses deposition of large volumes of milky quartz and pyrite. Stage II includes gray and buck quartz, pyrite and minor calcite, sphalerite, subordinate chalcopyrite and gold ores. Stage III consists of comb quartz and calcite, magnetite, sphalerite, chalcopyrite, arsenopyrite, pyrrhotite and gold ores. Studies on regional geology, ore geology and ore‐forming stages have proved that the Qolqoleh deposit was formed in the compression–extension stage during the Late Cretaceous–Tertiary continental collision in a ductile–brittle shear zone, and is characterized by orogenic gold deposits. 相似文献
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Mineralogy of the Boroo Gold Deposit in the North Khentei Gold Belt,Central Northern Mongolia 
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下载免费PDF全文 Mineral assemblages and chemical compositions of ore minerals from the Boroo gold deposit in the North Khentei gold belt of Mongolia were studied to characterize the gold mineralization, and to clarify crystallization processes of the ore minerals. The gold deposit consists of low‐grade disseminated and stockwork ores in granite, metasedimentary rocks and diorite dikes. Moderate to high‐grade auriferous quartz vein ores are present in the above lithological units. The ore grades of the former range from about 1 to 3 g/t, and those of the latter from 5 to 10 g/t, or more than 10 g/t Au. The main sulfide minerals in the ores are pyrite and arsenopyrite, both of which are divisible into two different stages (pyrite‐I and pyrite‐II; arsenopyrite‐I and arsenopyrite‐II). Sphalerite, galena, chalcopyrite, and tetrahedrite are minor associated minerals, with trace amounts of bournonite, boulangerite, geerite, alloclasite, native gold, and electrum. The ore minerals in the both types of ores are variable in distribution, abundance and grain size. Four modes of gold occurrence are recognized: (i) “invisible” gold in pyrite and arsenopyrite in the disseminated and stockwork ores, and in auriferous quartz vein ores; (ii) microscopic native gold, 3 to 100 µm in diameter, that occurs as fine grains or as an interstitial phase in sulfides in the disseminated and stockwork ores, and in auriferous quartz vein ores; (iii) visible native gold, up to 1 cm in diameter, in the auriferous quartz vein ores; and (iv) electrum in the auriferous quartz vein ores. The gold mineralization of the disseminated and stockwork ores consists of four stages characterized by the mineral assemblages of: (i) pyrite‐I + arsenopyrite‐I; (ii) pyrite‐II + arsenopyrite‐II; (iii) sphalerite + galena + chalcopyrite + tetrahedrite + bournonite + boulangerite + alloclasite + native gold; and (iv) native gold. In the auriferous quartz vein ores, five mineralization stages are defined by the following mineral assemblages: (i) pyrite‐I; (ii) pyrite‐II + arsenopyrite; (iii) sphalerite + galena + chalcopyrite; (iv) Ag‐rich tetrahedrite‐tennantite + bournonite + geerite + native gold; and (v) electrum. The As–Au relations in pyrite‐II and arsenopyrite suggest that gold detected as invisible gold is mostly attributed to Au+1 in those minerals. By applying the arsenopyrite geothermometer to arsenopyrite‐II in the disseminated and stockwork ores, crystallization temperature and logfs2 are estimated to be 365 to 300 °C and –7.5 to –10.1, respectively. 相似文献
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Abstract. The Mutnovskoe deposit located in the Porozhisto‐Asachinskaya metallogenic province of South Kamchatka, Russia, is a polymetallic vein and Au‐Ag quartz vein associated type of hydrothermal deposit. The Mutnovskoe deposit is located inside a paleo‐caldera structure at the center of the Mutnovsko‐Asachinskaya geothermal field of Pliocene ‐ Quaternary age, where active gold deposition is identified in hot spring precipitate. The Mutnovskoe deposit is subdivided into the north flank, the central flank and the south flank based on the vein distributions and mineral parageneses. The mineralized vein system is oriented N‐S hosted in diorite ‐ gabbroic diorite stock, volcanic rocks and sedimentary rocks of Miocene ‐ Pleistocene age. The mineralization stage I (polymetallic vein) mainly in the central and the south flanks is Zn‐Pb‐Cu‐Au‐Ag contained in sphalerite, galena and tetrahedrite‐tennantite group mineral. The stage II (Au‐Ag quartz vein) occurs in the north and the central flanks. The stage III (Mn‐sulfide and Mn‐Ca‐carbonate vein) occurs in the whole deposit area. Stage II is the typical Au‐Ag quartz‐adularia vein of low‐sulfidation type. Stage III is alabandite‐rhodochrosite‐quartz‐calcite vein. The K‐Ar ages are 1.3±0.1 Ma for stage I sericite in alteration zone, and 0.7±0.1 Ma for the stage II adularia in mineralized vein. Based on the fluid inclusion study, range of ore forming temperature of the Mutnovskoe deposit is 200 to 260d?C (av. 230d?C). Salinities of fluid inclusions indicate 2.2 to 5.7 wt% NaCl in sphalerite and 0.8 to 3.3 wt% NaCl in quartz for the stage I. Mineral paragenesis of the polymetallic vein (stage I) is characterized by a district zoning of tennantite and Cd‐rich sphalerite in the south flank and tetrahedrite and Mn‐rich sphalerite in the central flank, which is due to the fractional crystallizations of ore‐forming fluid. Depositional condition of the low sulfidation state is inferred for the Mutnovskoe deposit, where the polymetallic vein of the south flank is in relatively higher sulfidation state than the central flank. 相似文献
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黑刺沟金矿床以富As和Sb的微细浸染蚀变岩型金矿化和部分石英脉型锑－金矿化为特征,典型矿物组合为黄铁矿-毒砂(辉锑矿)-石英;贾公台金矿床以少硫化物石英脉型金矿化和蚀变岩型金矿化为特征,As和Sb的质量分数不高,典型矿物组合为黄铁矿-自然金(方铅矿)-石英-钾长石;鸡叫沟金矿床以蚀变岩型金矿化为主,次之为石英脉型金矿化,典型矿物组合为黄铁矿-黄铜矿-石英.3个金矿床的成因均与岩浆岩有密切联系,但各矿区的岩浆岩在岩石学、岩石化学、微量元素及稀土元素特征具有差异,表明其成因不尽相同.这可能是造成3个金矿床地质特征差异的主要原因. 相似文献
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南龙王庙金矿位于华北克拉通北缘,产在清原群表壳岩的北东端.主要容矿岩石为新太古代的磁铁石英岩,控矿构造为葫芦头沟-大荒沟韧性剪切带.矿石以细脉-浸染状构造为主.主要蚀变类型有白云母化、硅化、绿泥石化、碳酸盐化和绿帘石化.对矿区细脉-浸染状矿石石英中的流体包裹体进行了系统的岩相学、显微测温分析.结果显示,矿石石英中存在两个不同阶段的流体包裹体：早阶段形成的包裹体主要为含子矿物的三相包裹体（I）;晚阶段形成的包裹体包括气液两相包裹体（II）、纯CO2包裹体（III）和含CO2三相包裹体（IV）三种类型.流体演化过程为：早阶段的中温、高盐度、中等密度的流体,萃取清原群表壳岩中的Au;晚阶段在剪切带韧性变形向脆性变形转化过程中,流体演化为中温、中低盐度、低密度的特征,Au成矿元素达到饱和,在有利的构造空间沉淀成矿.成矿作用的方式由早期的扩散交代逐渐转变为晚期的充填作用,分别形成细脉-浸染状矿体和含金黄铁矿石英脉型矿体. 相似文献