江西大背坞金矿床矿石物质组成及金的赋存状态

大背坞金矿床属贫硫化物石英脉型,该矿床有用组分唯有Ａｕ,自然金是Ａｕ最主要的赋存形式,几乎集中富集了全部Ａｕ组分。虽然矿石中有极微量地银矿,并在方铅矿中发现可能还存在存在次显微金,但含量却微不足道,石英,黄铁矿,毒砂是自然金的主要载体,自然金成高色高,我以中粗粒裂隙金形式产出,粒间金次之,包裹金较少。     

胶东玲珑金矿田金的赋存状态及其对成矿过程的指示意义

胶东地区是我国最大的黄金基地,探明黄金资源储量超过5000t。胶东地区金矿床主要发育两种矿化样式,即浸染状细脉-网脉型矿化和石英-硫化物脉型矿化,金主要以可见金形式赋存于黄铁矿和石英中。玲珑金矿田位于招平断裂带北端,同时发育两种矿化样式的矿体,是研究金赋存状态的理想选区,理清金的赋存状态对于选择合适的选冶工艺以及揭示金的成矿作用和富集机制具有重要的研究意义。在详实的野外地质调查基础上,通过显微岩相学观察、电子探针分析与矿物自动定量分析,对胶东玲珑金矿田两种不同矿化样式的样品中可见金的赋存状态进行了对比研究,探讨了金成矿过程。玲珑金矿田两种矿化样式矿石中金矿物的赋存状态并无显著差异,金矿物主要为银金矿和自然金。嵌布状态为裂隙金、包体金、粒间金,以粒间金和包体金为主。金矿物粒度以微粒-细粒为主,石英脉中偶见中粒-粗粒金矿物。金矿物主要以独立矿物形式以及与黄铜矿、方铅矿等硫化物共生的形式赋存于黄铁矿中。石英-黄铁矿阶段金矿物成色高于石英-多金属硫化物阶段金矿物成色,主要是受到成矿温度的影响。浸染状细脉-网脉型样品金矿物比石英-硫化物脉型样品金矿物具有更高的金成色,是由于两种矿化样式沉淀机制差...     

张八岭构造带两种类型金矿次显微金赋存状态的质子探针分析

金属硫化物中次显微金的赋存状态已引起人们的重视。张八岭构造带蚀变构造岩型和石英脉型两类金矿金属硫化物中次显微金质子探针分析显示，Au与As、Fe、S、Cu、Pb呈正相关关系，Au以显微包裹体形式存在于金属硫化物中。与蚀变构造岩型金矿相比，晚期的石英脉型金矿可见自然金含量较高，硫化物中显微包裹体金含量较低，可能预示中低温热液金矿中，不仅普遍存在时空分异的金属硫化物中的类质同象金和自然金，还可能存在一定程度的时空分异的自然金和次显微包裹体金。     

黔西南簸箕田卡林型金矿中含砷黄铁矿和毒砂的赋金特征研究

黔西南簸箕田金矿是新近发现的一个中型卡林型金矿。该文在显微镜矿相学观察的基础上,采用电子探针显微分析, 包括背散射电子图像、点分析和面分析,对金矿中的赋金矿物展开了基本特征和赋金状态研究,发现含砷黄铁矿和毒砂是 主要的赋金矿物。赋金黄铁矿又以环带状和细粒自形为主,莓球状、粗粒以及条带状次之。这些黄铁矿成因复杂,并且可 能普遍受到热液蚀变作用影响。环带状黄铁矿核部中的金可能主要以“不可见”超显微包裹金（纳米级自然金,Au0）的形 式赋存,而环带部分中的金可能以固溶体金（Au+）的形式赋存,并也可能存在纳米级自然金（Au0）。相比而言,莓球状、 粗粒和条带状黄铁矿中的金既可能含有纳米级自然金（Au0）,也可能含有固溶体金（Au+）。对于毒砂,单独的毒砂和黄铁 矿- 毒砂集合体中的毒砂均为热液成因,都赋存金,但以单独的毒砂为主,金以“不可见”超显微包裹金（纳米级自然金, Au0）的形式存在。     

新疆西准噶尔哈西金矿矿石矿物特征及金赋存状态研究

哈西金矿位于新疆托里县哈图金矿的西南部,是近期发现的一个具有较大成矿潜力的金矿。矿体受北东向安齐断裂控制,长短不一,厚度为0. 10～3. 42 m,Au品位为0. 17～64. 60 g/t,主要赋存在石炭系太勒古拉组中,且与玄武岩关系密切。原生矿石可分为蚀变岩型及石英脉型两种,矿石矿物主要有黄铁矿、毒砂、黄铜矿、辉砷镍矿和自然金等。根据矿物共生组合规律,可将金矿形成的过程划分为2个成矿期次(热液期、表生期)和4个成矿阶段(石英-硫化物阶段、石英-硫化物-自然金阶段、碳酸盐阶段、氧化阶段)。自然金主要赋存形式为裂隙金、包裹金和粒间金,其成色平均为954. 19‰,粒径主要集中在20～50μm之间,属于显微金。     

阳山金矿带金的赋存状态及其对成矿过程的指示意义

阳山金矿带是西秦岭金矿带已探明金储量最大的独立金矿区,其矿化样式主要为微细浸染状矿化,其次为石英脉型矿化,可见金与“不可见金”均有发育,该金矿带是研究造山型金矿金赋存状态的理想地区,其研究成果对理解金成矿作用和过程以及指导选矿工艺具有重要意义。论文在翔实的野外地质调查和显微观察基础上,将成矿期划分为早阶段(黄铁矿石英)、主阶段(黄铁矿毒砂绢云母石英)和晚阶段(辉锑矿石英方解石),综合应用电子探针、激光剥蚀电感耦合等离子体质谱、电感耦合等离子质谱仪、高分辨率透射电镜、X射线粉晶衍射等技术,剖析阳山金矿带不同成矿阶段金的赋存状态,进而探讨其对成矿过程的指示意义。研究表明：成矿早、主阶段以微细浸染状硫化物矿化为主,金主要以晶格金的形式赋存于黄铁矿和毒砂中;而成矿晚阶段以脉状矿化为主,金主要以自然金的形式存在。金的赋存状态的变化,指示从成矿早阶段到晚阶段,成矿温度、压力逐渐降低,成矿流体成分由富As流体演化为相对贫As且富Sb的流体。     

石英脉型金矿床的成矿流体研究及思考

石英脉型金矿是常见的金矿床类型.金主要以粒间金、裂隙金和包裹金3种形式赋存于石英、黄铁矿等金属硫化物中.目前了解此类金矿的成矿流体组成主要是通过石英中的流体包裹体成分的定量和定性分析结果,揭示矿床成因.但是野外和室内镜下的综合研究已证实,金矿的形成经历了若干个成矿阶段.每个阶段都有石英和金属硫化物形成,而石英要明显早于金属硫化物的结晶,同时金在硫化物中的存在形式多为包裹金和裂隙金,这至少说明金和硫化物同时结晶沉淀或金比硫化物更晚沉淀.因此,金运移沉淀结晶时的流体和石英结晶时的流体存在着明显的时间差,金矿化与黄铁矿等金属硫化物有着密切的联系.研究金属硫化物中的流体包裹体来反映主成矿阶段的成矿流体物质来源,比研究石英中的流体包裹体更具有实际的意义.     

内蒙古白音哈尔金矿床矿石及金矿物特征

内蒙古白音哈尔金矿床矿石类型以贫硫化物含Au石英脉型为主，深部见含Au破碎蚀变岩型，主要载金矿物是石英，黄铁矿和褐铁矿，金的赋存状态为包裹体金，裂隙金和晶隙金，金矿物主要以中粗粒以上颗粒为主，占面积比的91.21%。矿床的形成经历2个成矿期4个成矿阶段，即热液期的石英，多金属贫硫化物及碳酸盐阶段和表生期的氧化淋滤阶段。     

海南王下牙老金矿床矿石特征

王下牙老金矿为贫硫化物方解石-石英脉型金矿床,矿体严格受断裂裂隙控制.矿石的有用组分单一,有害杂质少,金矿物主要为自然金.主要的金属矿物为毒砂、黄铁矿,同时也是主要的载金矿物;非金属矿物为石英、碳酸盐矿物.矿石多具自形、半自形、他形粒状结构,以脉状、浸染状构造为主.自然金形态为角粒状、长角粒状,赋存状态以粒间金为主,其次为包裹金,裂隙金仅占8.2%,自然金为显微金.矿石类型以含金方解石-石英复合脉为主,其次为含金构造角砾岩型和含金蚀变岩型.     

海南定安富文金矿床矿石特征

从不同标高、不同品位的矿石选矿试验研究入手，论述了富文金矿矿石的物质组成、矿物成分、结构构造、金的赋存状态等。研究表明，该金矿为中型特高硫化物含金石英脉型金矿床，矿体严格受断裂裂隙控制。矿石的有用组分多样，有害杂质少，金矿物主要为自然金。主要金属矿物为黄铁矿、毒砂，同时也是主要的载金矿物；非金属矿物为石英、碳酸盐矿物。矿石多具自形、半自形、他形粒状结构，以脉状、浸染状构造为主。自然金形态为尖角粒状、角粒状、长角粒状，赋存状态以裂隙金为主，其次为粒间金，包裹金占16．9％，自然金为细粒金。矿石类型为富金银多金属硫化物含金石英脉型。     

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.     

祁连山西段党河南山北坡3个不同特征的金矿床研究

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.     

Mineralogy of the Boroo Gold Deposit in the North Khentei Gold Belt,Central Northern Mongolia

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.     

云南大坪超大型金多金属矿床地质地球化学特征

大坪金矿床是哀牢山金矿带上的超大型金多金属共生矿床.矿体为赋存于闪长岩体内部近平行的多金属硫化物-石英薄脉.矿床地质、流体包襄体地球化学和同位素地球化学研究表明:成矿作用与中、新生代的区域构造-岩浆活动密切相关,至少可分为燕山期石英-黄铁矿和喜山早期石英-方铅矿两期;早期形成金矿化,晚期形成铅和银矿化并伴生金矿化;二者叠加于同一容矿空间,形成多期叠加的复式铅、锌、银、金共生矿床.成矿物质与成矿流体的来源一致,各成矿期流体均是以深源流体为主的壳-幔混合流体,但具有不同的地球化学特征,是相对独立的成矿流体体系.矿床成因属中-高温热液硫化物-石英脉型.     

北山地区金矿床金的赋存状态和金矿物特征

甘肃北山地区金矿床主要有岩浆热液型金矿床和与韧性剪切带有关的金矿床,矿化类型为石英脉型和蚀变岩型。金多呈独立金矿物形式出现,少放许呈分散状;金矿物以银金矿为主,次为自然金,平均成色７７２;金矿物以粒间金、裂隙金、连生金、连生金和包体金等形成嵌布于石英、黄铁矿、方铅矿及闪锌矿等主要载物较为发育。金矿物特征反映出本区金矿床的成矿物质主要来源于变质岩,华力西－印支期中酸性岩浆活动是主要的动力源。     

桂西那弱银金矿床矿物组合特征及银和金的赋存状态研究

广西天峨那弱银金矿床以银矿为主,共/伴生金及铅、锌、锑等金属,矿物组合在右江盆地内为首次发现。矿体受那弱背斜及其轴向断层控制,赋矿层位为中三叠统百逢组含钙质浊积岩系。矿石矿物以硫锑铅矿、铁闪锌矿、黄铁矿、毒砂和方铅矿为主;脉石矿物主要有石英、方解石、绢云母等。主要矿石矿物由早到晚的生成顺序为:毒砂→黄铁矿→铁闪锌矿→硫锑铅矿→方铅矿。单矿物化学分析显示硫锑铅矿含Ag最高,其次为闪锌矿;黄铁矿含Au相对较高。EPMA测试结果表明Ag于方铅矿中含量最高,其次为硫锑铅矿;主要矿石矿物中毒砂含Au相对较高,其余矿物中Au含量均偏低。因矿石中的铅矿物主要为硫锑铅矿,可以认为那弱银金矿床的Ag主要赋存于硫锑铅矿中,Au主要赋存于毒砂与黄铁矿中,二者均以显微-次显微状态赋存于载体矿物中。根据矿物组合及其相互交代、切割关系等特征,将矿床划分为2个成矿期共4个成矿阶段。其中,第一成矿期为金的成矿期,矿物组合为黄铁矿和毒砂,由于后期成矿作用的叠加,仅保留一个成矿阶段;第二成矿期为银铅锌成矿期,矿物组合为方铅矿-闪锌矿-硫锑铅矿;包含第二至第四共3个完整的成矿阶段。该矿床Ag、Au共生是不同期次成矿作用叠加的结果。     

Ore-microscopic and geochemical characteristics of gold-bearing sulfide minerals,El Sid Gold mine,Eastern Desert,Egypt

Gold deposits at El Sid are confined to hydrothermal quartz veins which contain pyrite, arsenopyrite, sphalerite and galena. These veins occur at the contact between granite and serpentinite and extend into the serpentinite through a thick zone of graphite schist. Gold occurs in the mineralized zone either as free gold in quartz gangue or dissolved in the sulfide minerals. Ore-microscopic study revealed that Au-bearing sulfides were deposited in two successive stages with early pyrite and arsenopyrite followed by sphalerite and galena. Gold was deposited during both stages, largely intergrown with sphalerite and filling microfractures in pyrite and arsenopyrite.Spectrochemical analyses of separated pyrite, arsenopyrite, sphalerite and galena showed that these sulfides have similar average Au contents. Pyrite is relatively depleted in Ag and Te. This suggests that native gold was deposited in the early stage of mineralization. Arsenopyrite and galena show relatively high concentrations of Te. They are also respectively rich in Au and Ag. Tellurides are, thus, expected to be deposited together with arsenopyrite and galena.     

脉状热液金矿垂向分带及深部预测（一）——成矿阶段及垂向分带概述

经过对４个金矿区带的系统调查研究。发现脉状热液金矿由早而晚具有磁黄铁矿－石英、黄铁矿－毒砂,黄铁矿－石英大脉、金－脉状黄铁矿、金银－多金属硫化物、金银－碲化物,黄铁矿－石英－碳酸盐７个阶段,矿床之间的差异只是成矿阶段系列发育的完整程度和成矿阶段发育的强度不同。在矿床、矿带和矿田范围内,都具有由上而下,由早而晚的金矿化垂向相对分带,Ａｕ,Ｃｕ,Ｚｎ,Ｐｂ,Ａｇ存在明显的时空变化趋势。     

古利库金(银)矿床地质特征和成因

古利库金(银)矿床为冰长石-绢云母型,产出与燕山中期"减压-剪切"环境下中心式火山喷发活动有关;矿床(体)受火山穹隆和爆破角砾岩筒及北西向、北东向断裂构造控制;容矿岩石为早白垩世龙江组、光华组安山岩、英安岩和新元古界-下寒武统落马湖群糜棱岩化的长英质片岩、片麻岩;矿床划分出矿化早期、主期和晚期3个矿化期,6个成矿阶段,3类组分矿体(Au型、Au-Ag型和Ag型)和脉状、网脉状两种形态矿体;围岩蚀变主要有硅化、冰长石化、绢云母化、白云石化、黄铁矿化等,硅化和冰长石化与矿化关系最密切;成矿温度185~255℃;成矿压力13.5 MPa (平均);成矿溶液盐度0.564% NaCl (平均);成矿深度500~600m.文中对成矿作用、矿床成因和成矿模式亦进行了探索和阐述.     

The Arinem Te‐Bearing Gold‐Silver‐Base Metal Deposit,West Java,Indonesia

The vein system in the Arinem area is a gold‐silver‐base metal deposit of Late Miocene (8.8–9.4 Ma) age located in the southwestern part of Java Island, Indonesia. The mineralization in the area is represented by the Arinem vein with a total length of about 5900 m, with a vertical extent up to 575 m, with other associated veins such as Bantarhuni and Halimun. The Arinem vein is hosted by andesitic tuff, breccia, and lava of the Oligocene–Middle Miocene Jampang Formation (23–11.6 Ma) and overlain unconformably by Pliocene–Pleistocene volcanic rocks composed of andesitic‐basaltic tuff, tuff breccia and lavas. The inferred reserve is approximately 2 million tons at 5.7 g t^?1 gold and 41.5 g t^?1 silver at a cut‐off of 4 g t^?1 Au, which equates to approximately 12.5t of Au and 91.4t of Ag. The ore mineral assemblage of the Arinem vein consists of sphalerite, galena, chalcopyrite, pyrite, marcasite, and arsenopyrite with small amounts of pyrrhotite, argentite, electrum, bornite, hessite, tetradymite, altaite, petzite, stutzite, hematite, enargite, tennantite, chalcocite, and covellite. These ore minerals occur in quartz with colloform, crustiform, comb, vuggy, massive, brecciated, bladed and calcedonic textures and sulfide veins. A pervasive quartz–illite–pyrite alteration zone encloses the quartz and sulfide veins and is associated with veinlets of quartz–calcite–pyrite. This alteration zone is enveloped by smectite–illite–kaolinite–quartz–pyrite alteration, which grades into a chlorite–smectite–kaolinite–calcite–pyrite zone. Early stage mineralization (stage I) of vuggy–massive–banded crystalline quartz‐sulfide was followed by middle stage (stage II) of banded–brecciated–massive sulfide‐quartz and then by last stage (stage III) of massive‐crystalline barren quartz. The temperature of the mineralization, estimated from fluid inclusion microthermometry in quartz ranges from 157 to 325°C, whereas the temperatures indicated by fluid inclusions from sphalerite and calcite range from 153 to 218 and 140 to 217°C, respectively. The mineralizing fluid is dilute, with a salinity <4.3 wt% NaCl equiv. The ore‐mineral assemblage and paragenesis of the Arinem vein is characteristically of a low sulfidation epithermal system with indication of high sulfidation overprinted at stage II. Boiling is probably the main control for the gold solubility and precipitation of gold occurred during cooling in stage I mineralization.