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1.
镇旬铅锌矿田主要矿物的标型特征研究   总被引:1,自引:1,他引:0  
侯满堂  王文昭 《陕西地质》2000,18(2):9-15,37
闪锌矿、方铅矿、黄铁矿、石英及重晶石镇旬铅锌矿田的主要矿物,不同世代的闪锌矿,其形态,颜色及矿物共生组合的差异,反映了形成条件的差异,主要矿物的化学成份。微量元素含量,反映了本区铅锌矿床与西成一凤太地区的喷流沉积改造型铅放床一样,即与国内岩浆热液型铅锌矿床有相似之处,更与典型的沉积改造型铅锌矿床类型。  相似文献   

2.
通过贵州天柱重晶石矿整装勘查,在天柱云洞重晶石矿床下部发现铅锌矿体,矿体产于陡山沱组地层中,呈层状产出,规模较大,具有"上部重晶石矿,下部铅锌矿"的分布规律。从矿床地质、地化特征等方面研究,获得该矿床属于热水喷流沉积成因的初步证据。通过与典型SEDEX铅锌矿床对比,云洞地区铅锌矿的矿体形态、矿物组合、矿石组构、围岩蚀变,以及沉积、构造环境等,都与典型SEDEX铅锌矿床具有相似性。根据沉积、构造背景分析,认为湘西黔东具备热水喷流沉积(SEDEX)型铅锌矿床的成矿条件,预测天柱坪地—新晃—玉屏一带具有寻找大型铅锌矿床的前景。  相似文献   

3.
辽东早元古代地层内赋存着一系列多金属硫铁矿床。矿床的形成与分布主要受裂谷盆地演化及含矿建造控制。在不同的演化阶段分别形成了含钴黄铁矿 含铜黄铁矿 含硬石膏黄铁矿矿床系列和含硼(镁电气石)磁黄铁矿 含铅锌黄铁矿 重晶石闪锌黄铁矿矿床系列。依据成矿特征可分为海底火山喷气沉积与海底喷气沉积两种成因类型。成矿作用受裂谷、次级盆地、一定含矿层位和特殊容矿岩石相互联系与配套的控矿因素制约。在对成矿规律研究的基础上将该区多金属硫铁矿划分为6个成矿远景区。  相似文献   

4.
云洞铅锌矿床位于南华裂谷盆地之雪峰次级裂谷盆地,赋矿地层为震旦系陡山沱组,容矿围岩主要为碳酸盐岩,少量为碎屑沉积岩,矿体呈层状、似层状产出,矿物以闪锌矿、黄铁矿及少量方铅矿,矿石结构主要有晶粒、交代残余结构,矿石构造主要为星点状、条纹状、角砾状、细粒浸染状、脉状,围岩蚀变为碳酸盐化、硅化、重晶石化。硫同位素为δ34S在+135‰+229‰之间,碳同位素为δ13CPDB=-47‰-842‰之间;氧同位素为δ13OPDB=-1331‰-1464‰,成矿温度142℃255℃,属中低温成矿流体,铅锌矿床受地层、岩相及构造热液双重因素控制,矿床成因属中低温沉积改造型矿床。成矿作用经历了沉积成岩和后期热液改造阶段。  相似文献   

5.
通过实地地质调查和取样测试,对二里河铅锌矿床进行标型矿物微量元素、围岩稀土元素地球化学特征、流体包裹体特征分析。结果表明:二里河铅锌矿床具有海底热水喷流沉积矿床一般地质特征,多期(华力西期+印支期)构造运动和幅度较大的裂陷发育史为大量矿质的喷流和聚集提供了十分有利的导矿和容矿构造条件。标型矿物微量元素地球化学特征显示:闪锌矿明显富集Cd((6 493.74~7 225.68)×10-6),贫Sb、As,黄铁矿w(S)与w(Se)比值为23 443.48~250 284.36,w(Co)与w(Ni)比值为3.47~104.10,指示矿床具热水沉积特征,而黄铁矿w(Fe)/(w(S)+w(As))为0.87~1.52,表明该矿为浅部成因矿床;流体包裹体特征、围岩和闪锌矿稀土元素显著亏损Eu、Ce,指示二里河铅锌矿床可能具有喷流沉积型矿床远源矿化特征;log(δCe)为-0.04~0.04,表明二里河铅锌矿床围岩在还原环境下成岩;石英流体包裹体均一温度及闪锌矿成分指示的温度范围(215℃~333℃)特征表明该矿床为中温矿床。综上所述,二里河铅锌矿床可能为相对远离喷流口的喷流沉积型浅层中温层状矿床。  相似文献   

6.
北山铅锌黄铁矿矿床位于广西壮族自治区环江毛南族自治县上朝镇北山村附近。目前,关于该矿床的成因尚存在争议,其中较具代表性的观点有:沉积-改造矿床,热卤水热液矿床,喷流沉积矿床。鉴于此,本文在阐述北山铅锌黄铁矿矿床地质特征的基础上,从含矿岩性组合、矿石矿物特征、区域白云石化等方面,对矿床的成因进行探讨,以期待为区域上同类型矿床的找矿勘探实践提供指导。  相似文献   

7.
新疆和田火烧云铅锌矿的发现,标志着我国铅锌找矿在西昆仑甜水海地区取得了重大突破,区内目前已发现铅锌矿床(点)29处,其中铅锌矿中型矿床7个、大型矿床2个、超大型矿床1个。通过收集整理区内最新的矿产地质勘查成果资料,对该区带内铅锌矿的成矿特征、找矿前景进行系统分析与总结,将区内铅锌矿床划分为密西西比河谷型(MVT)和沉积喷流型(SEDEX) 2个大类和4个具体类型,认为它们的成矿过程分别与区域大地构造演化、区域断裂活动及同沉积断层-喷流沉积活动密切相关,在矿体形态、矿石矿物、矿石结构构造等矿化特征及成矿模式方面均有明显差异。火烧云式是受中侏罗统龙山组上段灰岩-白云岩沉积层位控制的沉积喷流型铅锌矿,化石山式是受中侏罗统龙山组铁锰质沉积层位控制的沉积喷流型铅锌矿,多宝山式是受断裂构造控制的碳酸盐岩建造中的MVT型铅锌矿,元宝岭式是受北东向左行张扭性断裂控制的碎屑岩建造中的MVT型铅锌矿。  相似文献   

8.
盆地构造演化、流体系统、矿化作用是当代矿床学研究的新课题。盆地演化过程中,压实流体系统温度场、动力场和地球化学场可以通过地质研究和数字模拟来重塑。粤北晚古生代沉积盆地存在三种类型的矿化流体。大宝山型流体与岩浆热动力作用有关,形成海底火山热液沉积多金属矿床;凡口型流体与深部建造的循环热液有关,形成中低温海底热泉喷溢沉积铅锌银汞矿床;红岩型流体与盆地成岩压实水有关,形成低温单一黄铁矿矿床。粤北晚古生代盆地沉积物主要由透水性较好的粗碎屑物质和碳酸盐组成,沉积建造厚度较薄,数字模拟结果表明,盆地压实流体系统难以形成较高的地热储和流体势,不可能形成自身的突发喷溢。但在同生断裂作用引导下,流体在沉积层的特殊部位汇聚形成红岩型低温黄铁矿矿床。  相似文献   

9.
乌拉根铅锌矿带位于塔里木盆地以西喀什凹陷北部的乌恰凹陷中,该矿床δ34S值-25.9‰~27.5‰,显示出较宽泛的分布范围,本文通过对乌拉根铅锌矿床S同位素的研究,分析了成矿物质来源和矿床形成过程。该矿区硫同位素具有混合BSR作用形成的生物硫和海相沉积的膏岩矿物硫的特征,塔里木盆地西缘的新生界沉积盆地内大量发育的天青石、石膏、重晶石等硫酸盐矿物,为乌拉根铅锌矿床的铅锌矿化提供了充足的硫源。在其成矿作用过程中,盆地流体中的金属物质与来自于膏盐层溶解并进过生物还原作用形成的还原性硫结合导致硫化物的沉淀成矿。乌拉根铅锌矿床属砂砾岩型铅锌矿床。  相似文献   

10.
三江县老堡铅锌矿床为广西首次发现的一个中型扬子型铅锌矿床.矿区内共圈定铅锌矿体11个,均呈层状、似层状产于震旦系上统老堡组硅质岩、下统陡山沱组白云岩层间构造中,与地层同步褶曲.矿石组分相对简单,主要金属矿物有闪锌矿、方铅矿,次为黄铁矿:非金属矿物主要有白云石、石英、方解石,次为重晶石和绢云母.围岩蚀变较弱,以白云石化、硅化和方解石化为主.通过综合分析矿床地质、流体包裹体和稳定同位素等证据,笔者认为老堡铅锌矿床为热水沉积一中低温热液改造成因.成矿金属和硫源多来源于地层,少部分来自热液流体.成矿流体为地层中的环流热卤水.  相似文献   

11.
青海抗得弄舍重晶石型金多金属矿床成矿地质特征   总被引:1,自引:0,他引:1  
抗得弄舍重晶石型金多金属矿床为近几年在东昆仑成矿带东段新发现的典型的热水喷流沉积型金多金属矿床,目前该矿床金矿和铅锌矿的规模均已达大型以上,矿床的发现对东昆仑成矿带东段的找矿带来了新的生机和活力。该矿床以典型的热水沉积岩重晶石含金矿为特点,矿床受地层岩性和同生断裂构造双重控制,矿化与蚀变具有明显的空间分带特征。研究表明硫化物中的铅主要来自地幔,硫来自海水或者海相硫酸盐。指出成矿作用经历了早期喷流沉积成矿期,主要在中低温条件下形成铅锌硫化物矿;晚期热水沉积成矿期,主要在低温条件下形成重晶石和金矿;后期热液及构造活动对矿床有了进一步的富集和改造。  相似文献   

12.
Abstract: The Ashele Cu-Zn deposit is a recently discovered volcanogenic massive sulfide deposit in Xinjiang, Northwestern China. It is the largest Cu-Zn deposit in this type of deposits in China, which were formed in the early period of later Palaeozoic Era. This deposit is hosted within a suit of bimodal submarine volcanic rocks of the Ashele Formation of Lower-Middle Devonian System formed in an environment of paleocontinental margin rift setting. Lensoid orebodies occur between spilitic rocks developed at footwall and quartz-keratophyric tuff at hanging wall. Zonation of metal elements in the Ashele mine is one of typical volcanic-related exhalative Cu-Zn sulfide deposits in the world. Black ores enriched in Pb, Zn and Ag occurs on the top of the No. 1 orebody in the Ashele deposit, yellow ores enriched in Cu in the middle part, and the chalcopyritization stringer below the massive sulfide ores. Zonation of ore-structure in the No. 1 orebody is also apparent and corresponds to the zoning of elements, i. e. lamellar and/or banded sulfide-sulfate ores on the top, massive sulfide ores in the middle, and stockwork veinlets associated with altered breccia pipe on the bottom. Four epochs of mineralization in the Ashele deposit has been recognized. The first period of syngenetic-exhalative deposition of sulfides is the main epoch of mineralization, and the ores deposited subsequently subjected to thermo-metamorphism at the second epoch, superimposed by hydrothermal mineralization at the third epoch, and weathered or oxidized at the fourth epoch.
More than 100 categories of minerals have been recognized in the Ashele mine, but only pyrite, chalcopyrite, sphalerite, tetrahedrite, galena, barite, quartz, chlorite, sericite, and calcite are dominant, making up various types of ores, and alteration pipes or horizons. Studies of ore petrology suggest that the massive ores were volcanogenic and deposited by exhalative process.  相似文献   

13.
郭锐  彭恩生 《矿产与地质》2008,22(6):506-509
尖笔岽铅锌矿床位于粤东晚休罗世火山岩盆地中,矿化类型为独特的细脉浸染型脉状矿体,具热液矿床特征。矿石的结构构造研究表明矿液致裂现象明显,成矿溶液在成矿过程中参与了容矿构造的形成,矿化发生于控矿断层形成的雏形阶段。矿床的成因类型为与深部同熔型岩浆来源有关的岩浆期后热液矿床。  相似文献   

14.
上庄坪铅锌银矿床是新一轮国土资源大调查中在北秦岭二郎坪群发现的硫化物矿床。笔者通过对矿床矿石、容矿同岩、重晶石岩的微量、稀土元素地球化学特征分析和地质特征研究,探讨成矿构造环境、成矿物质来源及矿床成因问题。研究表明.矿石和容矿围岩稀土元素球粒陨石标准化组成模式均为右倾型.矿石与围岩在Cu-Pb-Zn判别图解中投点区域一致.矿石Zn/(Zn Pb)与冲绳海槽和上向黑矿矿石特征相似、与TAG和EPR13°N区硫化物存在差异.矿石具较高As、Sb和Pb与低Cu、Cd和Se元素特征.认为该矿床成矿元素来源于壳幔混合、但以壳源为主的围岩变(石英)角斑岩和变细碧岩。矿石稀土元素、微量元素地球化学特征、矿床地质特征及与热水沉积重晶石岩和硅质岩的紧密共生关系说明,上庄坪矿床是弧后盆地构造环境海底热液喷流成岩成矿作用的产物。重晶石岩、硅质岩、矿床纵向和横向分带是寻找和勘探该类矿床的重要标志和依据。  相似文献   

15.
Although the Mehdiabad zinc-lead deposit is one of the most well-known deposits in the central Iran structural zone, the genesis of the deposit remains controversial. The host rock of the ore is a dolomitic limestone of the Lower Cretaceous Taft Formation. In the two main orebodies of the deposit, which includes the Black Hill and East Ridge ore zones, the oxide and sulfide ores are observed at the surface and at depth, respectively. The elements Zn, Fe, Mn and Mg are more abundant in the East Ridge ore zone (in both sulfide and oxide ores), with Ba, Pb, Ag and Cu being more abundant in the Black Hill oxide ore. Based on the distribution of elements and their correlation with each other in these ore zones, the elements are divided into three general groups, that of terrigenous elements, chemically-deposited elements and ore-forming (hydrothermally deposited) elements, a division that is supported by the results of factor analyses. The spatial distribution of elements is jointly affected by contact with host rocks, the boundary of oxide-sulfide ores and fault zones. The main factors governing the distribution of elements are the mechanical transfer of detrital sediments, chemical sedimentation, transfer by hydrothermal fluids, oxidation and surface dissolution, all of which affected the spatial distribution of elements. The ore-forming elements are mostly affected by hydrothermal fluids and oxidation. This study not only provides additional information about the genesis of the Mehdiabad deposit, but also could assist in the exploitation of ore and further exploration purposes. The results of this study can aid in the exploration and exploitation of the Mehdiabad deposit and similar deposits in the region.  相似文献   

16.
天柱大河边重晶石矿床铅同位素特征及来源探讨   总被引:12,自引:0,他引:12  
对取自天柱大河边重晶石矿床的重晶石样品和含方铅矿黑色页岩样品进行了铅同位素测定与研究.结果表明,在 Zartman铅构造模式图中,重晶石矿石、含方铅矿黑色页岩和黑色页岩有大致相同的铅同位素分布区,均沿上地壳铅演化线分布,表明它们之间具有同源关系;重晶石矿石及其赋矿黑色页岩的铅同位素组成与基底地层的铅同位素组成在 Zartman铅构造模式图中具有完全不同的分布范围,表明重晶石矿石中的铅不大可能来源于基底地层;结合重晶石矿石及其赋矿黑色页岩的铅同位素组成在 Zartman铅构造模式图和Δγ-Δβ铅来源分类图的分布,天柱大河边重晶石矿床的铅主要具上地壳铅、壳幔混合的俯冲带铅和热水沉积作用铅的混合来源特点,这为天柱大河边重晶石矿床的热水沉积成因提供了铅同位素证据.  相似文献   

17.
四川呷村V HMS矿床:从野外观察到成矿模型   总被引:22,自引:11,他引:11  
呷村矿床是一个与晚三叠世海相钙碱性酸性火山岩系有关的典型块状硫化物(VHMS)矿床。热水流体系统和贱金属成矿作用发育于义敦岛弧碰撞造山带上的弧间裂谷盆地内,并受其内部的一系列局限盆地及SN向基底断裂-裂缝系统控制。含矿岩系为双峰岩石组合,具火山碎屑岩-矿体-喷气岩“三位一体”特征。硫化物矿床具有“块状矿席+层控网脉状矿带”式三维结构特征。块状矿席发育多旋回的硫化物-硫酸盐韵律型式,揭示热水流体在海底的幕式排泄以及硫化物-硫酸盐在卤水池内的韵律式化学淀积和滑塌堆积过程。层控网脉状矿带产出于流纹质火山岩系,与上覆的块状矿席平行展布,揭示高渗透性碎屑岩层和多条同级别断层或断裂共同约束海底下部热水流体,并诱导其“弥散式”排泄和侧向流动交代。热水流体的传导冷凝过程导致硫化物沉积、热水流体与冷海水的简单混合导致硅质岩或/重晶石淀积,传导冷凝与海水混合的联合作用导致含硫化物重晶石、硅质岩和红碧玉形成。  相似文献   

18.
滇西北兰坪中—新生代沉积盆地产有中国最大的铅锌矿床,巨量铅锌矿石集中产在金顶穹窿内,矿石中不同产状的干酪根、轻质原油、重油、烃类气、沥青等多种成熟形式的有机物质丰富。对矿区有机物质进行了岩相学、生物标志化合物、碳同位素及铅同位素分析,结果显示:有机物质中氯仿沥青“A”的质量分数为(72~395 415.42)×10^-6,w(饱和烃)/w(芳香烃)普遍大于1,饱和烃中检测出丰度较高的正构烷烃、Pr、Ph和iC18等生物标志化合物,烃源母质为藻类生物Ⅰ型有机质;相对于区域岩石,矿石中有机物质的有机转化率较低(0.5%~7.2%,平均为3.05%),已明显受热而成熟;透射全色光和紫外光显微镜在矿石光薄片样品中鉴别出较多原油和烃类气体包裹体。研究表明:金顶穹窿具有油气成藏“生、运、储、盖、闭”等配套发育的良好条件,矿区油气显示和古油气藏遗迹明显,铅锌成矿前或成矿中可能已形成油气藏;这个可能的油气藏以富含原油、烃类和H2S等还原性气体为成分特征;金顶古油气藏中H2S等还原性气体的聚集及其导致铅锌硫化物快速集中沉淀是大规模成矿的关键,成藏—成矿是金顶穹窿中一个连续发生、发展的动力学过程,成藏是成矿的前提。  相似文献   

19.
甘肃北山拾金坡金矿床地质特征及成因分析   总被引:1,自引:1,他引:1  
安国堡 《矿床地质》2006,25(4):483-490
拾金坡金矿是甘肃北山南带较为典型的含金硫化物石英脉型金矿床,矿化富集与加里东晚期—海西早期拾金坡复式岩体密切相关。矿体产于岩体的内接触带,产出部位明显受近EW向断裂破碎带的控制。矿体主要为大脉状、脉状、透镜状。矿床中发育一套典型的中温热液成因的矿物组合,矿石以强烈的绢云母化、碳酸盐化、硅化和黄铁矿化为特征,矿石的金属矿物组合为自然金_银金矿_黄铁矿_方铅矿_闪锌矿_黄铜矿,矿化属中温热液成因。硫和铅同位素显示成矿金属物质主要来自围岩,即斑状花岗岩;氢和氧同位素组成表明成矿流体来自花岗岩浆水。成矿时代属早—中海西期。因此可推断,拾金坡金矿床属于与构造_岩浆活动有关的中温岩浆热液成因矿床。  相似文献   

20.
H. Sun  J. Wu  P. Yu  J. Li 《Mineralium Deposita》1998,34(1):102-112
The Jingtieshan deposit occurs in a Precambrian tectonic-stratigraphic terrane within the Northern Qilian Caledonian Orogen, and is generally considered as a Superior-type iron formation. The deposit is characterized by Fe-Si-Ba and Cu mineralization and consists of two types of orebodies, an upper jasper-barite-iron deposit and a lower copper sulfide deposit. The iron orebodies occur as independent stratigraphic layers concordant within a thick argillaceous succession, and exhibit fine-grained textures and well-developed sedimentary layering. The ores are predominantly composed of specularite and jasper with lesser amounts of magnetite, hematite, siderite, and barite. The presence of barite, hematite and jasper as major components shows that the iron ores were precipitated in a relatively oxidized ocean floor environment. The Cu orebody directly underlies the iron ore and is hosted by chlorite-sericite-quartz phyllite. The Cu mineralization is composed of pyrite and chalcopyrite and is characterized by stockwork. The disseminated and stockwork Cu mineralization is metamorphosed and concordant with respect to foliation, indicating pre-fabric development, i.e. pre-metamorphism, and was probably originally formed by reduced fluids reacting at the base of and within the oxide iron formation. Geochemical data show that the jasper-barite-iron ores, which resemble Superior-type iron formations, have a high input of hydrothermal-hydrogeneous elements (SiO2, av.=56%; Fe2O3t, av.=30%; Mn, av.=0.45%; BaO, av.=16.7%) with minimal terrigeneous input (<15% combined Al2O3, TiO2, K2O, MgO, etc.). The δ34S of exhalative barite varies from 28 to 34‰, which is very heavy with respect to other Late Proterozoic sulfate-bearing deposits, except those of circa 600 Ma in which the sulfides range from 8 to 20‰. The sulfur isotope data indicate that the barite was formed by the mixing of a Ba-rich hydrothermal fluid with sulfate-rich ambient seawater and that the sulfides ores were most probably derived from the reduction of seawater sulfate during subsurface reaction with ferrous iron-bearing minerals. These data are consistent with the jasper-barite-iron deposit forming by hydrothermal exhalative and chemical sedimentary processes on the floor of an ocean basin, and with the Cu mineralization forming by hydrothermal filling and replacement in base of and within the iron formation. Received: 19 March 1997 / Accepted: 14 May 1998  相似文献   

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