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1.
巴达铜金矿位于藏东富碱斑岩带南段,是藏东地区近年来新发现的大型铜金矿。虽然对巴达铜金矿开展了大量勘查工作,但对该矿床的成因尚未取得共识。本文基于详细的野外调研、岩心与坑道编录及系统的镜下鉴定,对巴达铜金矿床地质特征进行研究。巴达矿床主要产于石英二长斑岩中,局部产于斑岩和砂岩地层的接触带内。矿床发育的围岩蚀变主要为青磐岩化、钾化、绢英岩化,高岭土化、蛋白石化、蒙脱石化次之,蚀变分带从内向外依次为钾硅酸盐化带、绢英岩化带、青磐岩化带、高岭土化带,铜金矿体主要赋存于钾硅酸盐化和绢英岩化带内,铜矿化主要以黄铜矿形式产出,金矿化主要以银金矿形式产于白云石±石英+细粒黄铁矿±黄铜矿脉中,铜矿化与金矿化呈正相关,矿体的产出受北西向逆冲断层的控制。与典型斑岩和浅成低温热液矿床不同,巴达铜金矿化主要产于白云石±石英+黄铁矿脉中;矿床内既发育碳酸盐、伊利石、绢云母和黄铁矿、黄铜矿、方铅矿、黝铜矿、低FeS闪锌矿等一套中硫型浅成低温热液矿床的蚀变矿物组合,又发育符合碱性斑岩系统的特征矿物赤铁矿。基于以上特征判断,巴达铜金矿矿床成因类型应为与富碱斑岩有关的浅成低温热液矿床,巴达铜金矿矿床成因的厘定,为下一步找矿提供了理论指导。 相似文献
2.
The Laowan metallogenic belt in China is an important metallogenic belt within the Tongbai orogenic belt, and contains the medium-sized Laowan and Shangshanghe gold deposits, the small Huangzhuyuan lead–zinc–silver–gold deposit and some gold and Cu–Pb occurrences. These deposits are hosted in Mesoproterozoic plagioclase amphibolite (or schist) and mica-quartz schist. The gold ores are mainly quartz veins and veinlets and disseminated altered ores. Subordinate ore types include massive sulfides and breccias. The Laowan gold deposit is characterized by three right-stepping en-echelon fracture-controlled alteration zones that dip gently to the south and includes disseminated, sheeted and stockwork ores. These lodes were formed by the interaction of ore-forming fluid with foliated-to laminated cataclasite within the transpressional faults. The Shangshanghe gold deposit is characterized by parallel ore lodes that dip steeply to the north, and includes quartz veins and breccias in addition to ores in altered wallrocks. These lodes were formed by focusing of fluids into transtensional faults. These ore controlling faults displaced early barren quartz veins 10 m horizontally with a dextral sense of motion. The ore-hosting structures at the Laowan and Shangshanghe deposits correspond to the P and R-type shears of a brittle dextral strike-slip fault system, respectively, which make angles of about 15° and − 15° to the Laowan and Songpa boundary faults. The ore-controlling fault system post-dated formation of a ductile shear zone, and peak regional metamorphism. This precludes a genetic relationship between hydrothermal mineralization and regional metamorphism and ductile shear deformation. These gold deposits are not typical orogenic gold deposits. The metallogenic belt displays district-scale-zoning of Mo → Cu–Pb–Zn–Ag → Au relative to Songpa granite porphyry dike zone, suggesting the mineralization may be closely related to the granite porphyry. Measured δ34S of sulfides and δ18O and δD of fluid inclusion waters in auriferous quartz also are consistent with a magmatic source for sulfur and ore fluids. The similarity of Pb isotope ratios between the ores and Yanshanian granitoids suggests a similar source. As the age (139 ± 3 Ma) of granite porphyry obtained by zircon U–Pb isotope overlaps the mineralization age (138 ± 1 Ma: Zhang et al., 2008a), the gold and polymetallic metallogenesis of the Laowan gold belt has close spatial, temporal and possibly genetic relationships with Yanshanian high level magmatism. 相似文献
3.
金厂金矿18号矿体围岩蚀变发育顺序从早到晚为:钾化、硅化、绿泥石化、绢云母化、碳酸盐化、高蛉土化,从内往外依次发育青磐岩化带、绢英岩化带和钾化带.矿化出现在泥化和绢英岩化叠加处,以及泥化和青磐岩化叠加处.通过短波红外光谱测试技术,识别出本矿区有26种蚀交矿物,其中白云母含量与金矿体呈正相关,说明绢云母化与金矿化关系密切;青磐岩化带蚀变矿物组合为绿泥石+绿帘石+伊利石±埃洛石±蒙脱石±石英;钾化带蚀变矿物组合为钾长石+高岭石+埃洛石±蒙脱石±石英;绢英岩化带蚀变矿物组合为绢云母+埃洛石±蒙脱石±高岭石±石英. 相似文献
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5.
新疆哈尔里克双峰山浅成低温热液金矿床的地质特征与成矿模式 总被引：1，自引：2，他引：1
对新疆东准噶尔哈尔里克构造带上双峰山金矿床的地质特征、矿床蚀变分带进行了初步研究，表明潜火山热液与火山热泉参与了成矿。这两个成矿阶段同源同位的蚀变矿物晕(带)叠套，造成双峰山矿床蚀变分带从上至下为隐爆硅质角砾岩化带、低金品位硅质岩带、石英(冰长石)网脉带(矿体)、黄铁矿蒙脱石化带和青磐岩化带。该矿床的成矿流体与晚古生代造山初期深成流纹质熔浆的陆相喷发有关。火山热泉循环形成蚀变晕，此阶段有大气降水的参与；潜火山热液成矿阶段发育的低温微细石英网脉中含冰长石和绢云母。双峰山矿床是晚古生代火山地区典型的冰长石-绢云母型浅成低温热液金矿床。 相似文献
6.
The world-class > 4 Moz Wona-Kona gold deposit is hosted within the Paleoproterozoic Birimian Houndé greenstone belt which is the most important gold mineralized belt in the western part of Burkina Faso, with a cumulative reserve of ~ 11 Moz. The mineralization consists of a pervasive silicification with disseminated pyrite–arsenopyrite crosscut by quartz–carbonate veinlets (1 to 10 cm wide) forming a vertical, thick (up to 40 m) and laterally extensive (5 km) northeast trending orebody hosted within a large (200 m wide) shear zone of regional extent. Gold occurs in association with 3 generations of pyrite and 2 generations of arsenopyrite. Free gold, interpreted as the last mineralizing event, occurs as late fracture filling in the pervasive silicification zone. 相似文献
7.
Peng Wang Wei Jian Jing‐Wen Mao Hui‐Shou Ye Wei‐Wei Chao Yong‐Fei Tian Jian‐Ming Yan 《Resource Geology》2020,70(2):169-187
The Songligou gold‐telluride deposit, located in Songxian County, western Henan Province, China, is one of many gold‐telluride deposits in the Xiaoqinling‐Xiong'ershan district. Gold orebodies occur within the Taihua Supergroup and are controlled by the WNW F101 Fault, and the fault was cut across by a granite porphyry dike. Common minerals in gold orebodies include quartz, chlorite, epidote, K‐feldspar, calcite, fluorite, sericite, phlogopite, bastnasite, pyrite, galena, chalcopyrite, sphalerite, tellurides, gold, bismuthinite, magnetite, and hematite, and pyrite is the dominant sulfide. Four mineralization stages are recognized, including pyrite‐quartz stage (I), quartz‐pyrite stage (II), gold‐telluride stage (III), and quartz‐calcite stage (IV). This work reports the Rb–Sr age of gold‐telluride‐bearing pyrite and zircon U–Pb age of granite porphyry, as well as S isotope data of pyrite and galena. The pyrite Rb–Sr isochron age is 126.6 ± 2.3 Ma (MSWD = 1.8), and the average zircon U–Pb age of granite porphyry is 166.8 ± 4.1 Ma (MSWD = 4.9). (87Sr/86Sr) i values of pyrite and δ34S values of sulfides vary from 0.7104 to 0.7105 and ?11.84 to 0.28‰, respectively. The obtained Rb–Sr isochron age represents the ore formation age of the Songligou gold‐telluride deposit, which is much younger than the zircon U–Pb age of the granite porphyry. Strontium and S isotopes, together with the presence of bastnaesite, suggest that the ore‐forming fluid was derived from felsic magmas with input of a mantle component and subsequently interacted with the Taihua Supergroup. Tellurium was derived from metasomatized mantle and was related to the subduction of the Shangdan oceanic crust and Izanagi plate beneath the North China Craton (NCC). This deposit is a part of the Early Cretaceous large‐scale gold mineralization in east NCC and formed in an extensional tectonic setting. 相似文献
8.
本文通过区域地质背景、矿区地质特征概况、矿床地质特征的分析研究,总结矿区内银多金属矿床的成矿规律.结果表明,矿体展布主要受石英斑岩的断层破碎带构造控制;石英斑岩体为银矿体的主要矿源体;石英斑岩岩浆的侵入在粉砂岩、含泥粉砂岩与角闪黑云石英二长岩体沉积接触的地质界面中,这种封闭构造环境中利于富集形成高品位的银矿石;矿化富集用与不同构造的交叉、构造形变强度、岩石破碎强度以及蚀变交代强烈程度等因素密切相关.可将石英斑岩的断层破碎带及接触蚀变带作为银多金属矿找矿方向.石英斑岩断层破碎带中的硅化、黄铁矿化、褐铁矿化、绿泥石化蚀变,是该区银矿找矿的一种地表直接标志. 相似文献
9.
位于青藏高原东缘的玉龙铜矿是我国最大的斑岩铜矿之一,其形成一致认为与矿区中心产出的二长花岗质复式斑岩体有关,但成矿与复式岩体的确切关系并不清楚。本文通过详细的野外地质填图,特别是矿床8号勘探线12个钻孔的重新编录,在复式岩体中识别出一套花岗斑岩岩枝,岩枝中不规则状石英-钾长石脉广泛发育,同时还见有单向固结结构、粗晶及细晶结构,这些特征表明该岩浆中的流体曾经发生过饱和。同时结合矿床高品位(0.6%,质量分数)铜矿化紧密围绕花岗斑岩分布、含矿脉体自花岗斑岩向外围逐渐由高温石英-钾长石A脉过渡为中低温石英-硫化物脉、热液蚀变自花岗斑岩向外由高温钾硅酸盐化过渡为中低温石英-绢云母化的规律,最终确定这套花岗斑岩为玉龙矿床的成矿斑岩。玉龙铜矿成矿斑岩的厘定,较好地解释了矿床矿化类型及金属的分布规律,为进一步深入理解矿床形成过程提供了帮助。 相似文献
10.
Peng Zhang Linlin Kou Yan Zhao Zhongwei Bi Deming Sha Renping Han Zhumin Li 《地学前缘(英文版)》2020,(2):547-563
TheWulong lode deposit contains over 80 tonnes of gold with an average grade of 5.35 g/t.It is one of the largest deposits in Dandong City,Liaoning Province in northeast China.Previous studies on the deposit focused on its geological characteristics,geochemistry,fluid inclusions,and the timing of gold mineralization.However,controversy remains regarding the origin of the ore-forming fluids and metals,and the genesis of the gold deposit.This paper presents zircon UePb and pyrite RbeSr ages and S,Pb,He,and Ar isotopic results along with quartz H and O isotopic data for all litho-units associated with the deposit.Laser ablation inductively coupled mass spectrometry measurements yielded zircon UePb dates for samples of pre-mineralization rocks like granite porphyry dike,the Sanguliu granodiorite,fine-grained diorite,and syn-mineralization diorite,as well as post-mineralization dolerite,and lamprophyre;their emplacement ages are 1261 Ma,1241 Ma,1231 Ma,1201 Ma,1192 Ma,and 1152 Ma,respectively.The pyrite RbeSr isochron age is 1191 Ma,indicating that both magmatism and mineralization occurred during the Early Cretaceous.The d18OH2O values of ore-forming hydrothermal fluids from the quartzepolymetallic sulfide vein stage vary from 4.8&to 6.5&,and the dDV-SMOW values are between67.7&and75.9&,indicating that the ore-forming fluids were primarily magmatic.The noble gas isotope compositions of fluid inclusions hosted in pyrite suggest that the ore-forming fluids were dominantly derived from crustal sources with minor mantle input.Sulfur isotopic values of pyrite vary between 0.2&and 3.5&,suggesting that S was derived from a homogeneous magmatic source or possibly from fluids derived from the crust.The Pb isotopic compositions of sulfides(207Pb/204Pb?15.51 e15.71,206Pb/204Pb?17.35e18.75,208Pb/204Pb?38.27e40.03)indicate that the Pb of the Wulong gold deposit is a mixture of crust and mantle components.Geochronological and geochemical data,together with the regional geological history,indicate that Early Cretaceous magmatism and mineralization of the Wulong gold deposit occurred during the rollback of the subducting Paleo-Pacific Plate,which resulted in lithospheric thinning and the destruction of the North China Craton(NCC),which indicates that the deposit is of magmaticehydrothermal origin. 相似文献
11.
为讨论石湖金矿的形成与麻棚花岗岩体、石英闪长玢岩脉之间的联系,对花岗闪长岩、石英闪长玢岩进行了U--Pb年代学研究,并分别对花岗闪长岩、石英闪长玢岩、矿化蚀变岩和围岩的地球化学进行了系统测定。麻棚花岗岩体U--Pb年龄为(124.8±1.4)Ma(MSWD=0.74),石英闪长玢岩脉年龄为(127.3±1.1)Ma(MSWD=1.15),但二者地球化学特征表现不同,应有不同起源。地球化学特征表明,麻棚花岗岩与矿化蚀变岩具有较一致的稀土、微量元素配分型式,而与围岩差别大,说明金矿的成矿流体来源与麻棚花岗岩关系密切。此外,花岗闪长岩具高钾钙碱性,且重稀土亏损、轻稀土富集、弱Eu异常、高Sr--Ba和高Sr/Y、La/Yb比值,表明麻棚岩体的形成有幔源岩浆的混入。笔者认为成矿流体和成矿物质来源为幔源岩浆底侵和混合,并以花岗岩浆为载体而迁移上升。结合矿床地质特征,初次提出闪长玢岩脉与矿体时空关系密切,这应是闪长玢岩脉作为隔流体层对来自麻棚花岗岩体的成矿流体具有一定的封闭作用,使得矿化、蚀变富集产出,即岩脉封闭作用。石湖金矿的成岩成矿机制与中生代期间岩石圈减薄的地球动力学背景密切相关,应是一种非造山型金矿。 相似文献
12.
《Russian Geology and Geophysics》2015,56(10):1384-1393
We studied the mineralogic and geochemical features of metasomatic rocks and ores from the Pogromnoe gold deposit, which is unconventional for Transbaikalia. The deposit, which formed in the Early Cretaceous, at the rifting stage of the regional evolution, is localized in the dynamoclastic strata of the Mongol-Okhotsk suture, along which the Siberian continent joined the Mongolia-China continent in the Early-Middle Jurassic. Gold mineralization occurs as two morphologic types of ores: stockwork quartz-carbonate-arsenopyrite-pyrite ores in altered volcanics (orebody no. 1) and veinlet-vein quartz ones (with disseminated sulfides) in altered carbonaceous shales (orebody no. 10). The host rocks of the deposit are the highly altered volcanosedimentary rocks of the Butorovskii Formation (Shadoron Group, J2–3), which transformed into metasomatic (by composition) and dynamoclastic (by texture and structure) rocks. It has been found that the formation of the metasomatic rocks and mineralization proceeded in several stages. Propylites formed at the preore stage (J3); tectonic schists and albitophyres, at the late preore stage; and sericitolites and albite-carbonate-sericite-quartz metasomatic rocks (quartzites), at the synore stage. The 40Ar/39Ar age of the stockwork system of ore-bearing fractures and metasomatic rocks which formed at the late preore stage is estimated as 139.5 ± 1.8 Ma. The gold-bearing rocks at the deposit are the late preore and synore metasomatic rocks formed after volcanics with sulfide mineralization (gold concentrators are pyrite II and III and arsenopyrite I and II) and after altered carbonaceous shales (gold concentrators are vein quartz and arsenopyrite II). Gold grade is completely consistent with silicification, saturation with quartz-sulfide and sulfide microveinlets, and fine sulfide dissemination. By genesis, the Pogromnoe deposit belongs to objects which formed in shear zones with the contribution of gold-bearing mantle fluids. The authors presume that the sources of mineralization are the ore-producing granitoids of the Amudzhikan-Sretensk intrusive assemblage within the Aprelkovo ore-magmatic system (OMS) (Os’kina and Urguchan plutons). This is confirmed by Pb isotope compositions (207Pb/204Pb and 206Pb/204Pb) for the pyrite and arsenopyrite of the Pogromnoe gold-bearing ores, which testify to the widespread occurrence of “mantle” Pb isotope signatures. The 40Ar/39Ar age of the ore-producing granitoids of the Aprelkovo OMS is 131.0 ± 1.2 Ma. Gold in the orebodies occurs in native form and is fine and very fine. By gold grade, the Pogromnoe deposit deserves very close attention as a new commercial type of gold mineralization in Transbaikalia. 相似文献
13.
朱阳关-夏馆断裂是一条长约400 km,深达上地幔的超壳深大断裂带,沿断裂带出露有较多的燕山期花岗岩(脉)体及一系列Cu、Au、Ag、Pb、Zn异常,有色金属、贵金属成矿作用明显。高庄金矿床赋存在二郎坪群含放射虫黄铁矿变细碧岩内,矿体成群成带分布在朱阳关-夏馆断裂次级断裂中,明显受断裂控制,近地表以石英脉型金矿为主,向下渐变为蚀变碎裂岩型金矿,矿体自地表向下明显变厚,金品位增富。其成因为海底火山喷流-岩浆热液-构造热液叠加改造形成的含金石英脉-蚀变构造岩型金矿。二郎坪群蛇绿岩套横贯河南省西南部,连续延伸约400 km(图1),含放射虫黄铁矿层广泛发育,Cu、Au、Ag、Pb、Zn异常分布较多,朱阳关-夏馆断裂的次级断裂中黄铁矿化、硅化、多金属硫化物蚀变明显,随着深部地质找矿的进一步开展,本区可成为我国重要的金多金属矿产基地。 相似文献
14.
早子沟金矿床是近年来在西秦岭地区发现的又一特大型金矿床。文章通过对该矿区矿体的矿化强度指数、品位变化规律的统计计算,建立了矿体金品位变异函数模型,分析研究了矿体金品位分形分布特征及矿体金金属量-平均品位特征。金品位变化规律及特征的研究表明,金矿体在深部向北东侧伏,金矿体品位呈波状变化,矿体金品位的对数转换分布基本服从正态分布,变异函数模型显示具有各向异性,北东55°方向为矿化最连续方向;金品位分形结构特征研究表明,对矿区资源储量贡献最大的矿石类型是石英细脉-网脉脉岩型矿石,脉岩与地层的内、外接触带及部分含矿小岩脉应是今后勘查的重点,沿倾向金品位具有明显的等间距变化特征,向北东方向每隔140~260 m将会出现富矿段。基于以上认识,结合矿体产出的空间位置、控矿构造条件,探讨了矿床深部找矿方向,总结了今后的勘查重点部位及重要的岩性组合。 相似文献
15.
上世纪90年代中期通过成矿预测发现的水银洞金矿床,通过近10年的勘查,成为特大型层控金矿床。矿体呈层状、似层状产出于灰家堡背斜轴部附近300m范围内二叠统龙潭组的大孔隙度生物碎屑灰岩中,形态与背斜形态一致。矿体严格受控于碳酸盐岩,顶板和底板皆为粘土岩或粉砂质粘土岩,界线清楚。矿化表现为“硅化、白云石化、黄铁矿化”组合。硅化与白云石化是成矿的先决条件,碳酸盐岩最终能否成矿及品位的高低,取决于是否具有黄铁矿化热液蚀变及其强度。矿床具矿体多、厚度薄、品位富的特点。单矿体即达中型矿床规模。具中—低温超高压热液成矿的特点。金赋存于沿自形黄铁矿内核生长成的含砷黄铁矿环带中。 相似文献
16.
岗岔—克莫金矿区位于西秦岭北缘夏河—合作成矿带,具浅成低温热液型矿床特征,初步显示深部可能具有斑岩成矿系统存在。利用短波红外光谱矿物分析技术对岗岔—克莫金矿区蚀变岩特征的研究表明,矿区内发育的蚀变矿物主要有白云母、伊利石、蒙脱石、高岭石、地开石、绿泥石、绿帘石和次生石英等。近矿蚀变类型主要为绢英岩化。矿区内以下家门沟口为中心向外依次发育了中心带(绢英岩化带)、过渡带(泥化带)和外围带(青磐岩化带)。此外,伊利石结晶度以下家门沟口为中心向外具有明显的降低趋势。研究结果指示下家门沟口可能是矿区的热液活动中心。 相似文献
17.
九十三沟金矿床产于延边复向斜北东端杜荒子-汪清中生代陆相火山断陷盆地东部的石英闪长斑岩内接触带角砾岩中,近南北向断裂构造控制金矿体的产出.成矿物质来自白垩纪浅成侵入体石英闪长斑岩,成矿热液为富含钾质的气水溶液.矿床属岩浆期后中低温热液型金矿床. 相似文献
18.
东伙房金矿位于内蒙古武川县,为一小型金矿床,属于与浅成花岗斑岩有关的中浅成中高温热液矿床.本次成矿预测思路为：在已知Ⅰ号矿体及其他含金蚀变带上,建立大量的观测点,把每个观测点的地质、地球物理、地球化学、矿物学等方面的成矿信息分析研究,并把Ⅰ号矿体作为已知矿体,总结Ⅰ号矿体的成矿信息特征,建立接近于客观实际的已知矿体模型,用之与其他含金蚀变带进行对比,从而预测出成矿的有利地段.作者把以上这种工作方法称为综合信息叠加组合及相似类比法.本次工作发现了两处较好的矿体,同时发现了一种新的矿化类型——斑岩型金矿化,这对该地区找矿预测具有重要意义. 相似文献
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白崖沟金矿床地处祁连-北秦岭造山带的巨大反“S”型构造南侧。金矿化受震旦-奥陶系李子园群和近EW向展布的断裂带及二长花岗岩体的控制．通过分析金矿化特征与围岩蚀变类型。认为与金矿化关系密切的热液活动主要分为4期,主要围岩蚀变类型为黄铁矿化、褐铁矿化、硅化和退色蚀变。文章总结了该矿床的矿化类型和特征．对成矿因素进行了分析,提出了找矿标志。 相似文献
20.
《International Geology Review》2012,54(5):438-448
Structural, geochemical, and isotope studies were carried out on the gold deposits of the Pontes e Lacerda region (Mato Grosso state, Brazil), where rocks of the Aguapei and Rondoniano mobile belts (southwestern Amazonian craton) occur. The orebodies are hosted in metavolcanic, gneiss-granite, quartzite, tonalite, and granite units. Tectonics involve oblique overthrusting (from northeast to southwest), which led to the formation of recumbent folds and thrusts (pathways for the mineralizing fluids), upright folds, and faults with dominant strike-slip component. These unconformities represent potential sites for mineralization. During geological mapping, it was observed that the orebodies consist of quartz, pyrite, and gold, and that the hydrothermal alteration zone contains quartz, sericite, pyrite (altered to limonite), and magnetite (altered to hematite). Chalcopyrite, galena, and sphalerite occur only in the Onca deposit. Chemical analysis of sulfides indicates high contents of Bi, Se, and Te in sulfides and gold, suggesting plutonic involvement in the origin of hydrothermal solutions. K-Ar dating of hydrothermal sericites from gold veins yielded ages in the range from 960 to 840 Ma, which may indicate the age of original crystallization of sericite. Pb-Pb dating in galenas yielded model ages in the range from 1000 to 800 Ma for the Onca deposit, which is in agreement with K-Ar ages. Pb-isotopic ratios indicate high U/Pb and low Th/Pb for the upper-crustal Pb source before incorporation in galena crystals. The Pontes e Lacerda gold deposits yielded ages correlated to the Aguapei event and probably were formed during a Proterozoic contractional tectonic period in the southwestern part of the Amazon craton, which may characterize an important metallogenic epoch in the Pontes e Lacerda region. 相似文献