贵州锦丰(烂泥沟)金矿床含砷黄铁矿和脉石英及其包裹体的稀土元素特征

贵州锦丰(烂泥沟)金矿是滇黔桂"金三角"目前已探明的最大的卡林型金矿床.含砷黄铁矿是该矿床最主要的载金矿物,脉石英是最显著的热液蚀变作用产物.含砷黄铁矿、脉石英及其包裹体具有相同的稀土元素特征,表现为轻重稀土分馏明显(LREE/HREE7.95～31.77,(La/Yb)N8.97～40.49);轻稀土有一定的分异((La/Sm)n3.20～5.29),曲线右倾程度大;重稀土分异不明显((Gd/Yb)n1.41～3.35),曲线平坦;负铕异常明显(δEu 0.59～0.71);微弱的铈负异常(δCe 0.97～0.98).代表成矿流体特征的脉石英包裹体稀土配分型式及特征值与区域上不同时代的幔源基性-超基性岩差别较大,而与矿床围岩、矿石、含砷黄铁矿及其包裹体稀土配分型式及特征值十分相似,具上部地壳普通沉积岩的特点,反映成矿流体主要不是来源于地幔,而是以壳源为主.Eu负异常反映了偏酸性(富CO2)、还原性的成矿环境;微弱的Ce负异常表明成矿流体来源于以沉积水和热脱水为主的盆地流体.     

贵州贞丰烂泥沟卡林型金矿床含砷黄铁矿Re-Os同位素测年及地质意义

贵州贞丰烂泥沟金矿(现称锦丰金矿)是滇黔桂“金三角”已知最大的卡林型金矿床,矿体赋存于断层破碎带内,最主要的载金矿物是具环带结构的含砷黄铁矿。本文运用Re-Os同位素法对该矿床的9个含砷黄铁矿样品进行了两次测试,成功获得10-9～10-12级Re-Os同位素数据:Re0.1257～1.233ng/g,Os6.75～33.50pg/g,等时线年龄为193±13Ma,反映其成矿时代为早侏罗世。等时线的初始n(187Os)/n(188Os)值为1.127±0.043,指示成矿物质来源于地壳而不是地幔。结合其他资料,初步建立其成矿模式为:盆地流体不断地从沉积物中萃取出包括金在内的成矿组分,形成含矿流体。印支期挤压造山期间,含矿流体沿不整合接触面和同生断层向上运动,造山后的伸展含矿流体进入减压扩容空间沉淀形成超大型金矿床。成矿作用发生在从印支期挤压造山向燕山期伸展转变的构造转换期。该模式与本文得到的成矿年龄和初始比值相吻合。     

贵州锦丰(烂泥沟)超大型金矿床构造解析及构造成矿作用

在矿区大比例尺填图的基础上,运用构造解析的理论和方法,对贵州锦丰(烂泥沟)金矿的构造特征、构造演化和构造控矿作用进行了系统的阐述。矿区构造线主要分为近NS向、NW向和NE向3组,其中NW向构造线控制了矿区的构造格架。构造变形主要经历了同生期裂陷、造山期挤压、后碰撞造山侧向挤压和岩石圈伸展等4个阶段。盆地裂陷期间(D2-T2)形成的同生断层为后续的构造活动提供了最初的构造薄弱面,并成为主要的热液通道;造山期挤压期间(T3)形成了矿区最为明显的近NS向和NW向大型倒转褶皱和逆冲断层以及配套的NE向右旋走滑断层;后碰撞造山侧向挤压期间(J1)形成走向NE的叠加褶皱,并在F2-F3"X"型断裂系上形成近EW向的拉张区,矿质沿着拉张的空间沉淀就位;燕山期(J2-K)岩石圈伸展,形成小规模的近水平逆断层。上述4个主要构造变形阶段与右江盆地的裂陷-闭合-坍塌的发展演化历史相吻合,成矿发生在由挤压向拉张过渡的构造体制转换阶段。造山期逆冲作用形成的构造闭圈和后碰撞造山期间挤压向伸展转变的过程中形成的局部张性构造环境是矿质得以大量聚集、沉淀的主要构造控制因素。构造成矿作用是锦丰(烂泥沟)金矿单一矿体垂向延深1000m以上的主要制约因素。构造成矿的观点将为在滇黔桂"金三角"卡林型金矿带的深部找矿提供重要的理论依据。     

玲珑-焦家式金矿床流体包裹体的稀土和微量元素特征

应用热爆提取和ICP—MS方法,研究了玲珑-焦家式金矿床脉石英和绢英岩中流体包裹体的微量元素特征。结果表明,流体包裹体中REE配分模式均表现为LREE富集型,轻、重稀土具有较好的分馏,LREE／HREE=6．07—26．41。但轻重稀土内部分异不明显,（La／Sm）N=2．15—5．11,（Gd／Lu）N=0．72—5．24。成矿流体具有弱的Eu正异常,δEu=1．05—7．09,与中高温、弱酸性的现代地热成矿系统相似。流体包裹体／中国陆壳元素丰度标准化后表明,流体中富集的重金属元素有Cu、Mo、Pb、Bi等,它们的富集系数大于1．成矿流体中亏损的元素有Ti、V、Cr、Co、Li、Zr、Nh、Th、U等。流体包裹体微量元素、稀土元素特征为金矿床的成因研究增添了新的证据。玲珑一焦家式金矿床的流体包裹体具相似的REE特征,而与其它地区的金矿床或其它类型的矿床则明显不同,说明该区金矿床成矿地球动力学背景相同,部与中生代燕山期构造体制转折条件下热液活动有关。     

贵州泥堡金矿床流体包裹体特征及其成矿意义

为揭示泥堡金矿床的成因机制,本文对泥堡金矿床两类矿体中的萤石、方解石中的流体包裹体进行了岩相学、显微热力学和单个包裹体成分的激光拉曼显微探针分析。结果表明,层控型矿体为早期成矿阶段的产物,其中的脉石矿物萤石中发育了气液两相水溶液包裹体、含CO2包裹体,其均一温度为220~260℃,盐度为0.00%~2.00%NaCleq,密度为0.54~1.03g/cm3;断裂带型矿体方解石中发育气液两相水溶液包裹体、含CO2气液两相包裹体和含子矿物的三相包裹体,其均一温度主要为100~200℃,盐度为3.00%~6.00%NaCleq,密度为0.69~1.00g/cm3。计算得到早期成矿阶段流体捕获压力为40~80MPa,成矿深度为1.5~3.0km;断裂带型矿体中流体的捕获压力为30~40MPa,成矿深度为1.0~2.5km。反映出初始流体的中-低温、低盐度、低密度并含CO2及CH4、N2等有机气体成分的特点。流体混合是导致成矿早期阶段矿质初步富集形成层控型矿体的原因,后期的断裂带活动引发的流体沸腾是形成断裂带型矿体的原因。     

山西灵丘梨园金矿床流体包裹体特征

梨园金矿床位于山西省灵丘县,矿床大地构造位置处于华北板块的燕山断块,在区域上位于呈NNE向展布的太行山—岩浆—多金属成矿带上。矿区出露的地层较为简单,主要新太古界阜平群的黑云斜长片麻岩和斜长角闪岩。矿区构造发育,特别是断裂构造最为明显,主要为NNE向、近EW向、NW向及NE向,其中NNE向断裂是主要的控矿构造,梨园金矿产于NNE向断裂F3及其派生断裂带和角砾岩带中。矿区内出露的岩浆岩有伟晶状钾长花岗岩、石英斑岩、闪长岩和辉绿岩。     

江西留龙金矿床含矿流体特征研究

论述了江西南部留龙金矿床中石英的流体包裹体形态及成分;测定了流体包裹体的温度、盐度;计算了含矿流体的压力、逸度〔ｆ（Ｏ２）,ｆ（ＣＯ２）〕、成矿深度;并对含矿流体演化过程进行了探讨分析。     

石英黄铁矿中群体包裹体微量元素研究——以胶东焦家式金矿床为例

采用ICP-MS测定了胶东焦家、马塘、东季和红布金矿床黄铁矿、石英及其群体包裹体的微量元素组成。结果表明,黄铁矿包裹体与石英包裹体均富集Cu、Pb和Zn等成矿元素,反映了成矿流体的特征;不同成矿阶段成矿流体特征有差异,石英黄铁矿化阶段、黄铁绢英岩化阶段、石英多金属矿化阶段石英及其包裹体微量元素含量均高于成矿较差的钾长石化阶段的石英及其包裹体;与陆壳微量元素丰度相比,黄铁矿及石英中Cu、Pb、Zn、Ag和Au等成矿元素富集;与地热卤水及斑岩铜矿卤水微量元素含量相比,黄铁矿及石英包裹体中以Cu为代表的成矿元素均较其它元素相对富集,反映了成矿流体中富集成矿元素的特征。上述结果表明,可以采用ICP-MS测定黄铁矿及石英包裹体微量元素来研究成矿流体的特征。     

含油气盆地中热流体活动的流体包裹体依据

为寻找含油气盆地中热流体活动的证据,根据国内外含油气盆地中与热流体有关的包裹体的对比研究,阐述了流体包裹体宿主矿物产状、形貌特点及均一温度实测值高异常等特征。研究表明,脉体矿物多数是与热流体活动有关的包裹体的宿主矿物,有些碎屑矿物成岩愈合微裂隙中的包裹体也与热流体活动有关。沸腾包襄体反映了油气成藏与热流体的脉动式活动密切相关。流体包裹体的均一温度高异常是由热流体活动所导致的。因此,流体包裹体研究对识别古热流活动具有重要的指示意义。     

Structural features and metallogenesis of the Carlin-type Jinfeng (Lannigou) gold deposit, Guizhou Province, China

Jinfeng, previously known as Lannigou, is the largest Carlin-type gold deposit in the Yunnan–Guizhou–Guangxi region in southwestern China. Gold mineralization in the Jinfeng deposit is almost entirely fault-hosted and structurally controlled, with very little disseminated ore occurring in the adjacent host rocks. The structural elements in the Jinfeng deposit can be subdivided into 3 groups comprising NS-, NW-, and NE-striking faults and folds, with NW-striking structures controlling the overall framework of the deposit. Four tectonic stages have been recorded in the Jinfeng area, i.e., rifting, orogenic compression, lateral transpression, and lithospheric extension. A series of contemporaneous normal faults, such as the N-striking and east-dipping F1 and F7 faults developed along the edges of a carbonate platform during basin rifting (D₂–T₂). These structures provided an initial framework for subsequent basin evolution, and also represent the principal hydrothermal conduits. A gradual change of the compression direction during the orogenic stage (T₃) from E→W to NE→SW, gave rise to the NW-striking structures, including large, tight to overturned folds such as the Huangchanggou synclinorium and associated thrusts such as the F3 fault. The development of these orogenic, predominantly NE-dipping structures, as well as accompanying NE-striking dextral shear and transform faults (such as the F2 fault) along the margin of the Laizishan Dome established the structural pattern of the deposit area. The NW-striking folds were refolded by NE-striking superimposed folds during post-collisional lateral transpression (J₁) and NW–SE directed compression. Oblique stress distribution gave rise to NS-trending compression and EW-trending extension, with dilational zones developing at the intersection of the F2 and the F3 faults east of the Laizishan dome. It is these dextral- and sinistral-normal dilational zones in which gold was precipitated during the main ore-forming event at Jinfeng. Following the main ore stage lithospheric extension occurred during the Yanshan stage (J₂–K) resulting in minor reverse faults that in places cut pre-existing structures. The above four main structural deformation stages mirror the evolution of the Youjiang Basin from inception to basin inversion and post-orogenic collapse and renewed extension. Significant gold metallogenesis at Jinfeng occurred during the transition from collisional compression to extensional tectonics in the early Jurassic, and is focussed into intersections of F2 and F3 and fault splays adjacent to F3. This structurally controlled gold metallogenic model is likely to be applicable to analogous settings elsewhere in the Yunnan–Guizhou–Guangxi triangle area, and has implications for the targeting of Carlin-type gold mineralization in this region.     

黔东南罗里金矿包裹体特征及成因探讨

石英脉型金矿是我国南方金矿重要的矿床类型,黔东南黎平罗里金矿就是其中之一。黎平罗里金矿为贫硫化物石英脉型金矿;矿脉相互关系、矿石结构构造和成矿流体盐度等特征均表明其成矿的多期多阶段性;金主要形成于成矿阶段,成矿流体均一温度主要集中在150～300℃,盐度集中在0.36%～15.76%,密度集中在0.59～0.97g/c...     

江南造山带中段正冲金矿矿床成因:来自流体包裹体和黄铁矿微量元素的证据

江南造山带上产出有大量金矿,但其成因存在争议,为厘清其成因,对该造山带上的正冲金矿床中的黄铁矿进行了LA-ICP-MS微量元素分析和流体包裹体研究.结果显示,正冲金矿的流体包裹体有含CO2包裹体、富CO2包裹体和水溶液包裹体,其中富CO2包裹体与水溶液包裹体共存,具有相似的均一温度,但盐度不同,说明流体不混溶可能导致了...     

Metallogeny of the Lannigou Sedimentary Rock-hosted Disseminated Gold Deposit in Southwestern Guizhou Province, China

The Lannigou deposit is a large-sized sedimentary rock-hosted disseminated gold （SRHDG） deposit located in the Youjiang Basin. It is hosted by the Middle Triassic turbidite. Wall rock alterations, including silicification, pyritization, arsenopyritization, carbonatization and argillization, commonly occur along fractures. PGE study demonstrates that either Permian basalts or Triassic ultrabasic intrnsives are unlikely to be the main source of gold mineralization. Coupled with the lack of other nmgmatic activity in the vicinity of the mining area, an amagmatic origin is proposed. Organic matter compositions and GC-MS analysis of the ores and host rocks show that the organics in the ores and the host rocks have a common source; the organic matter in the ores was mainly indigenous. The positive correlation between S2 and Au contents, along with the common occurrence of organic inclusions, suggest involvement of organic matter in the ore-forming process in terms of promoting Au leaching from the source rocks, making colloidal Au migration possible, as well as hydrocarbon reduction of sulphate. Geological and geochemical characteristics of the Lannigou deposit suggest that it was formed through circulation of meteoric water and probably less importantly organic bearing formation water driven by high geothermal gradient caused by late Yanshanian extension, which leached Au from the source bed, and then migrated as Au-bisnlfides and colloidal Au, culminating in deposition by reduction-adsorption and surface complexation of gold onto the growth surface of arsenlan pyrite.     

黔东平秋金矿含金石英脉包裹体地球化学

本文主要通过包裹体岩相学特征、测温及成分分析等几个方面,对锦屏县平秋金矿含金石英脉的包裹体进行研究。结果显示成矿流体主要表现为具岩浆热液性质的中低温、低盐度、低密度的热液。     

甘肃合作早子沟金矿床流体包裹体及硫铅同位素特征

早子沟金矿床是西秦岭西段近年来发现的大型金矿床之一。矿床产于中三叠世古浪堤组中,矿体产出与中酸性岩脉关系密切;矿体受断裂控制,呈脉状、条带状,少数似层状产出。含金石英脉可分为两个成矿期次,分别为含金粗粒石英脉期和多金属硫化物-金石英期;金属硫化物主要为辉锑矿、黄铁矿、毒砂等。辉锑矿石英脉型金矿石中流体包裹体主要为富液相的气液两相流体包裹体,均一温度为129.8 ~324.3 ℃,平均为203.2 ℃,盐度（w（NaCl））为1.22%~10.73%,平均为6.04%,成矿流体的密度平均为0.90 g/cm³,矿床的成矿平均深度约为2.00 km;阴阳离子分析结果表明,流体包裹体液相成分主要为Na⁺-SO₄^2--Cl^-,单个流体包裹体激光拉曼显示流体包裹体中的气相成分主要为H₂O、CO₂和SO₂,个别样品显示有CO和CH₄,成矿流体为NaCl-H₂O-CO₂体系。流体包裹体研究揭示了早子沟金矿床辉锑矿-金成矿阶段的成矿流体为浅成中低温低盐度低密度流体,主要为岩浆水与地下水的混合热液,不同性质流体的混合作用和它们的沸腾作用是使金沉淀的重要因素。矿石中辉锑矿硫同位素组成很稳定,δ³⁴S_V-CDT值为-10.30‰~-8.10‰,平均为-9.33‰,表明硫主要为岩浆热液来源,并混有地层硫。矿石铅同位素组成显示²⁰⁶Pb/²⁰⁴Pb为18.166~19.027,²⁰⁷Pb/²⁰⁴Pb为15.608~15.741,²⁰⁸Pb/²⁰⁴Pb为38.249~39.275,矿石铅同位素组成为壳幔混合成因铅。根据早子沟金矿床特征,结合成矿流体性质及来源、成矿物质来源研究成果,推测甘肃早子沟金矿床应为岩浆期后低温热液金矿床。     

玲珑金矿黄铁矿热电性与微量元素标型及深部金矿化评价

在前人对玲珑金矿矿体浅部的研究基础之上,通过对矿体深部黄铁矿的热电性测试与分析,得出：西山矿区380m—90m中段,黄铁矿导型以P—N型（空穴型-电子型导电）为主;东山矿区50m—850m标高范围内,黄铁矿导型以P—N或N—P（电子型-空穴型导电）混合型为主。东、西山矿区的P型出现率在垂向上呈高-低-高的韵律式脉冲变化...