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1.
The origin of PGE-Cu-Ni sulfide deposits of Norilsk and Talnakh located in the northwest flank of the Triassic basalt trap formation of Siberia is considered.It is shown that ore elements of these deposits (probably,except Fe) are derived from the crust rather than from the mantle.They entered the basalts owing to a remobilization (recycling) of ore elements from the Paleoproterozoic sediments and from the rocks of the Siberian platform's basement.Prospecting criteria for similar deposits are as follows:(1) a presence of a large Paleoproterozoic aulacogen and a related magmatic sulfide Cu-Ni mineralization; (2) a confinement of perspective areas to troughs associated with long-lived deep fault zones; (3) association with mobile orogenic belts,island-arc systems and tectonomagmatic activation zones; (4) temporal association with boundaries of global periods characterized by active processes of continental breakup and large-scale trap magmatism.A combination of several factors (the first one is obligatory) is favorable for the discovery of a large ore body. 相似文献
2.
我国一些铜镍硫化物矿床主要金属矿物的特征 总被引：7，自引：0，他引：7
镍、铜共生的铜镍硫化物矿床是镍矿也是铜矿的重要矿床类型。磁黄铁矿，镍黄铁矿、黄铜矿是这类矿床的主要金属矿物。它们的某些矿物学特征，特别是微量元素Ｃｏ／Ｎｉ比值，与其他铜矿类型明显不同，这三种矿物组成不同于任何其他铜矿类型的典型矿物共生组合， 形成特殊的海绵损铁状、球滴状构造。 相似文献
3.
金、铜、铅、锌(银)矿是辽宁地区的优势矿种,过去和现在都曾从多个不同角度或多个方面予以研究论述,但从成矿系列理论研究则是作者(1994)在Ⅱ轮区划工作中所做的一种新的尝试。根据程裕淇先生的成矿系列理论,辽宁地区早前寒武纪变质岩系中的金、铜、铅、锌(银)矿床属变质成矿系列组合,可进一步划分为三个成矿系列,六个成矿亚系列,九个矿床(种)类型和十二个矿床式。成矿系列特征表明成矿物质与原岩的含矿性关系非常密切,成矿物质或元素具有随原岩建造时空演化而演化的特点,成矿具有鲜明的专属性和层控性,是典型或比较典型的层控变质矿床。金矿床的形成和分布均与韧性剪切带及其糜棱岩有关,表明辽宁前寒武纪金矿床的形成不仅与变质作用有关,而且韧性剪切作用也是极其重要的成矿条件;铜、锌(银)和铅、锌(银)矿床以块状硫化物型为主,其成矿多与火山作用关系十分密切,变质作用过程中,发生重就位或再富集,或热液交代富集成矿。由太古宙至早元古代不同成矿系列或成矿亚系列中的矿床具有自下而上有序的空间分布规律。 相似文献
4.
位于芬兰北部中拉普兰绿岩带的克维特斯塔(Kevitsa)镍-铜-铂族元素矿床是世界上主要的岩浆镍-铜硫化物矿床之一。该矿床储量大,含丰富的镍-铜硫化物和铂族元素。对矿床产出环境、地质特征、矿床成因等进行了总结,结果表明:矿体主要赋存于克维特斯塔基性—超基性层状侵入体的超基性单元中。主要矿石类型为普通型和镍-铂族元素型2种,其中镍-铂族元素型矿石内橄榄石具极高的Ni含量。主要矿石矿物为磁黄铁矿、镍黄铁矿、黄铜矿、黄铁矿、针硫镍矿、红砷镍矿、砷镍矿、辉砷镍矿等,绝大部分铂族矿物包含在硅酸盐中和附着在硫化物颗粒边界。Re-Os、Sm-Nd、Sr及S同位素特征显示成矿岩浆为幔源,但受到地壳物质的混染作用。Pb同位素年代学结果表明克维特斯塔侵入体形成于古元古代。 相似文献
5.
The Ni-Co-(PGE) sulfide deposits of the Thompson Nickel Belt (TNB) in Northern Manitoba, Canada are part of the fifth largest nickel camp in the world based on contained nickel; past production from the TNB deposits is 2500 kt Ni. The Thompson Deposit is located on the eastern and southern flanks of the Thompson Dome structure, which is a re-folded nappe structure formed during collision of the Trans-Hudson Orogen with the Canadian Shield at 1.9–1.7 Ga. The Thompson Deposit is almost entirely hosted by P2 member sulfidic metasedimentary rocks of the Paleoproterozoic Ospwagan Group. Variably serpentinised and altered dunites, peridotites and pyroxenites contain disseminated sulfides and have a spatial association with sediment-hosted Ni sulfides which comprise the bulk of the ore types. These rocks formed from rift-related komatiitic magmas that were emplaced at 1.88 Ga, and subsequently deformed by boudinage, thinning, folding, and stacking.Disseminated sulfide mineralization in the large serpentinised peridotite and dunite intrusions that host the Birchtree and Pipe Ni-Co sulfide deposits typically has 4–6 wt% Ni in 100% sulfide. The disseminated sulfides in the less abundant and much smaller boudinaged serpentinised peridotite and dunite bodies associated with the Thompson Deposit have 7–10 wt% Ni in 100% sulfide. The majority of Thompson Mine sulfides are hosted in the P2 member of the Pipe Formation which is a sulfidic schist developed from a shale prololith; the mineralization in the schist includes both low Ni tenor (<1 wt% Ni in sulfide) and barren sulfide (<200 ppm Ni) and a Ni-enriched sulfide with 1–18 wt% Ni in 100% sulfide. The semi-massive and massive sulfide ores show a similar range in Ni tenor to the metasediment-hosted mineralization, but there are discrete populations with maximum Ni tenors of ∼8, 11 and 13 wt% Ni in 100% sulfide. The variations in Ni tenor are related to the Ni/Co ratio (high Ni/Co correlates with high Ni tenor sulfide) and this relationship is produced by the different Ni/Co ratios in sulfides with a range in proportions of pyrrhotite and pentlandite. Geological models of the ore deposit, host rocks, and sulfide geochemical data in three dimensions reveal that the Thompson Deposit forms an anastomosing domain on the south and east flanks of a first order D3 structure which is the Thompson Dome. In detail, a series of second order doubly-plunging folds on the eastern and southern flank control the geometry of the mineral zones. The position of these folds on the flank of the Thompson Dome is a response to the anisotropy of the host rocks during deformation; ultramafic boudins and layers of massive quartzite in ductile metasedimentary rocks control the geometry of the doubly-plunging F3 structures. The envelope of mineralization is almost entirely contained within the P2 member of the Pipe formation, so the deposit is clearly folded by the first order and second order D3 structures. The sulfides with highest Ni tenor (typically >13 wt% Ni in sulfide) define a systematic trend that mirrors the configuration of the second order doubly-plunging F3 structures on the flanks of the Dome. Although moderate to high Ni tenor mineralization is sometimes localized in fold hinges, more typically the highest Ni tenor mineralization is located on the flanks of the fold structures.There is no indication of the mineralogical and geochemical signatures of sedimentary exhalative or hydrothermal processes in the genesis of the Thompson ores. The primary origin of the mineralization is undoubtedly magmatic and this was a critical stage in the development of economic mineralization. Variations in metal tenor in disseminated sulfides contained in ultramafic rock indicate a higher magma/sulfide ratio in the Thompson parental magma relative to Birchtree and Pipe. The variation in Ni tenor of the semi-massive and massive sulfide broadly supports this conclusion, but the variations in metal tenor in the Thompson ores was likely created partly during deformation. The sequence of rocks was modified by burial and loading of the crust (D2 events) to a peak temperature of 750 °C and pressure of 7.5 kbar. The third major phase of deformation (D3) was a sinistral transpression (D3 event) which generated the dome and basin configuration of the TNB. These conditions allowed for progressive deformation and reformation of pyrrhotite and pentlandite into monosulfide solid solution as pressure and temperature increased; this process is termed sulfide kinesis. Separation of the ductile monosulfide solid solution from granular pentlandite would result in an effective separation of Ni during metamorphism, and the monosulfide solid solution would likely be spread out in the stratigraphy to form a broad halo around the main deposit to produce the low Ni tenor sulfide. Reformation of pentlandite and pyrrhotite after the peak D2 event would explain the broad footprint of the mineral system. The effect of the D3 event at lower pressure and temperature would have been to locally redistribute, deform, and repeat the lenses of sulfide.The understanding of the relationships between petrology, stratigraphy, structure, and geochemistry has assisted in formulating a predictive exploration model that has triggered new discoveries to the north and south of the mine, and provides a framework for understanding ore genesis in deformed terrains and the future exploration of the Thompson Nickel Belt. 相似文献
6.
中南部非洲镍矿资源丰富,大体可分为岩浆型和风化壳型2种预测类型。本文在对中南部非洲243处镍矿床/点资料系统收集整理的基础上,将产出的镍矿初步划分为新太古代、古元古代、中元古代和新元古代4个成矿期,南非卡普瓦尔北缘古元古代Cr-Ni-Cu（PGE）成矿带、津巴布韦大岩墙新太古代Ni-Cr（PGE）成矿带、博茨瓦纳弗朗西斯敦—赛莱比—皮奎新太古代Ni-Cu-Au成矿带、赞比亚赞比西津巴—卢萨卡新元古代Au-Ni-Cu成矿带、坦桑尼亚乌本迪—乌萨嘎仁古元古代Ni-Cu成矿带和坦桑尼亚—布隆迪基巴拉中元古代Ni-Cu-Co成矿带共6个成矿带,从整体上构成了北东向的中南部非洲巨型镍矿带;并分别对研究区内典型的与大陆边缘裂解有关的Ni-Cu（PGE）矿床、与造山带伸展背景有关的Ni-Cu矿床、与地幔柱有关的Ni-Cu（PGE）矿床和风化壳型镍矿床的矿床地质特征和成矿模式进行了研究。综合研究表明,布什维尔德矿集区、津巴布韦大岩墙矿集区、博茨瓦纳弗朗西斯敦—赛莱比—皮奎矿集区、坦桑尼亚—布隆迪穆松加迪—卡邦加矿集区镍矿资源潜力巨大,找矿前景优越。 相似文献
7.
沉积硫化物矿层形成的构造地球化学机制 总被引：1，自引：0，他引：1
在还原性海底水域中,厌氧细菌引起的还原作用提供了沉淀剂S~（2-）。这种作用控制着同生硫化物相的形成。盆地中古构造运动形成的沉降—堆积弱补偿状态是硫化物矿物富集的一种有利条件。在此情况下,硫化物层不受非矿物质的稀释。某些层控矿床的地质和地球化学资料证明,陆缘构造拗陷带的潮下海湾和泻湖相构成一种使陆源成矿元素聚集成矿床的“地球化学阱”。 相似文献
8.
Polymetallic Mineralization at the Nakakoshi Copper Deposits, Central Hokkaido, Japan 总被引：6，自引：0，他引：6
Abstract: Polymetallic mineralization at the Nakakoshi deposits, Kamikawa town, central Hokkaido, occur as fracture-filling veins in Cretaceous slate of the Hidaka Supergroup. Ten veins have been recognized in NE-SW and E-W directions. Sericite in altered slate which is the host of the deposits, was dated at 31. 1 Ma, Oligocene in age.
No. 9 vein consists of massive chalcopyrite ore with various kinds of minerals such as pyrite, pyrrhotite, arsenopyrite, sphalerite, tetrahedrite, Ag-minerals and Cu–Zn–Fe–In–Sn–S minerals, quartz and sericite. Chalcopyrite and pyrite contain sphalerite star and sphalerite with chalcopyrite emulsions. Maximum indium contents of sphalerite and the Cu–Zn–Fe–In–Sn–S minerals are 1. 8 and 16. 3 wt%, respectively. The sulfur isotopic ratios, δ34 S of ore minerals, range from –12. 9 to –9. 6%. Formation temperatures of the sulfide minerals are estimated as 300–500°C, based on the paragenesis and chemical compositions of the minerals. 相似文献
No. 9 vein consists of massive chalcopyrite ore with various kinds of minerals such as pyrite, pyrrhotite, arsenopyrite, sphalerite, tetrahedrite, Ag-minerals and Cu–Zn–Fe–In–Sn–S minerals, quartz and sericite. Chalcopyrite and pyrite contain sphalerite star and sphalerite with chalcopyrite emulsions. Maximum indium contents of sphalerite and the Cu–Zn–Fe–In–Sn–S minerals are 1. 8 and 16. 3 wt%, respectively. The sulfur isotopic ratios, δ
9.
塔里木克拉通东北缘坡北、磁海等地二叠纪幔源岩浆活动形成了镍钴硫化物矿床和铁钴氧化物矿床,两者赋矿镁铁-超镁铁岩体的年龄相近(290～260 Ma),主、微量元素和Sr-Nd-Hf同位素组成相似,分配系数接近的微量元素比值分布于相同趋势线,揭示两者岩浆源区相同,可能为俯冲板片流体交代的亏损地幔或软流圈地幔。两类矿床镁铁-超镁铁质岩中Co与Ni含量正相关,Co主要富集在基性程度高的岩石中;块状硫化物与磁铁矿矿石中Co与Ni相关性差,Co和Ni具有不同的富集机制,Co热液富集作用明显。北山镁铁-超镁铁杂岩体是地幔柱相关软流圈上涌,诱发俯冲板片交代的亏损岩石圈地幔发生部分熔融,形成的高镁母岩浆演化过程中经历壳源混染、硫化物饱和富集镍钴形成铜镍钴硫化物矿床,富铁母岩浆氧逸度高、富水,岩浆分离结晶磁铁矿、叠加热液作用富集钴,形成铁钴氧化物矿床。 相似文献
10.
Isotope geochemistry of the mafic dikes from the Vazante nonsulfide zinc deposit, Brazil 总被引：2，自引：0，他引：2
M. Babinski L.V.S. Monteiro A.H. Fetter J.S. Bettencourt T.F. Oliveira 《Journal of South American Earth Sciences》2005,18(3-4):293-304
The Vazante Group, located in the northwestern part of Minas Gerais, hosts the most important zinc mine in Brazil, the Vazante Mine, which represents a major known example of a hypogene nonsulfide zinc deposit. The main zinc ore is represented by willemite and differs substantially from other deposits of the Vazante-Paracatu region, which are sulfide-dominated zinc-lead ore. The age of the Vazante Group and the hosted mineralization is disputable. Metamorphosed mafic dikes (metabasites) that cut the metasedimentary sequence and are affected by hydrothermal processes recently were found and may shed light on the geochronology of this important geological unit. Zircon crystals recovered from the metabasites are xenocrystic grains that yield U–Pb conventional ages ranging from 2.1 to 2.4 Ga, so the basement of the Vazante Group is Paleoproterozoic or has metasedimentary rocks whose source area was Paleoproterozoic. Pb isotopes determined for titanite separated from the metabasites have common, nonradiogenic Pb compositions, which prevents determination of their crystallization age. However, the Pb signatures observed for the titanite crystals are in agreement with those determined for galena from the carbonate-hosted Zn–Pb deposits hosted by the Vazante Group, including galena from minor sulfide ore bodies of the Vazante deposit. These similarities suggest that the metalliferous fluids that affected the metabasites may have been those responsible for galena formation, which could imply a similar lead source for both nonsulfide and sulfide zinc deposits in the Vazante–Paracatu district. This common source could be related to deep-seated, basin-derived, metalliferous fluids associated with a long-lived hydrothermal system related to diagenesis and deformation of the Vazante Group during the Neoproterozoic. 相似文献
11.
Zahra BONYADI 《《地质学报》英文版》2022,96(6):2040-2055
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
12.
Volcanogenic massive sulfide deposits in ophiolite complexes are usually attributed to the Cyprus type. They associate with
basaltic volcanics that are formed in mid-ocean or back-arc spreading centers and much less frequently in intra-plate settings.
The deposits are characterized by copper or copper-zinc ores that are enriched in Ni, Co, and in places Mn and As, but are
very poor in Pb and demonstrate a low to moderate content of Ag and Au. Typically, the deposits are low to very low in ore
and metal reserves. Cyprus-type deposits were irregularly distributed during geological history. The most ancient of them
were formed in the Neoproterozoic, while the bulk of the deposits are Ordovician or Cretaceous in age. Their possible Paleoproterozoic
analogues can be found in the Svecofennian belt (Outokumpu ore district), while modern ones are confined to the Explorer and
Endeavour Ridges and southern segment of the Juan de Fuca Ridge. 相似文献
13.
A series of vanadium oxides—shcherbinaite, karelianite, kyzylkumite, coulsonite, and berdesinskiite—was found in association
with pyrrhotite in pyrite-pyrrhotite ore from the Paleoproterozoic Vihanti massive sulfide deposit of the Kuroko-type. It
is suggested that enrichment in vanadium of massive sulfide ore from the Vihanti deposit is a result of their metamorphogenic
regeneration and pyrrhotinization at the expense of rocks and ore enriched in vanadium. The list of rare minerals in massive
sulfide ore has been extended. 相似文献
14.
东昆仑志留纪辉长岩地球化学特征及与铜镍成矿关系探讨 总被引：1，自引：1，他引：0
东昆仑造山带新发现的夏日哈木超大型岩浆铜镍矿床、石头坑德大型岩浆铜镍矿床及冰沟南小型岩浆铜镍矿床,其矿体均赋存于橄榄辉石岩内,而辉长岩又是该含矿橄榄辉石岩的直接围岩,并且辉长岩的形成时代相近(夏日哈木辉长岩431Ma、石头坑德辉长岩425Ma、冰沟南辉长岩427Ma),产出位置属于同一大的构造单元,均邻近昆北及昆中断裂。通过对辉长岩的地球化学特征研究,发现明显富集轻稀土元素和明显的Nb-Ta负异常,亏损高场强元素。Sr-Nd同位素研究,表明东昆仑夏日哈木和石头坑德辉长岩岩体的母岩浆来自一个曾经被交代富集的地幔源区,可能揭示了由于从洋壳释放出的流体交代地幔楔的岩石成因。结合区域构造演化和辉长岩形成时代,认为东昆仑夏日哈木和石头坑德辉长岩形成于碰撞后伸展环境。辉长岩岩浆源区性质与赋矿辉石岩存在明显不同,并非同一岩浆活动的产物。辉长岩在东昆仑造山带地区直接充当了含矿辉石岩的直接围岩,与岩浆铜镍硫化物矿体的形成没有关系,富含橄榄石的超镁铁质岩石更有利于形成具有较大经济价值的铜镍矿体。这为指导东昆仑找矿实践和岩浆铜镍矿床成矿理论研究提供了基础。 相似文献
15.
中国岩浆硫化物矿床新分类与小岩体成矿作用 总被引：27，自引：7，他引：20
中国镍(铜、钴)、铂族等许多重要金属矿产都产出于岩浆硫化物矿床,该类矿床是矿床地质研究的热点之一。笔者综合构造背景、侵入方式、岩体规模、矿床模式、主成矿元素等因素,对中国岩浆硫化物矿床提出了新的分类:①古大陆内的小侵入体矿床;②与大陆溢流玄武岩有关的侵入体矿床;③造山带内小侵入体矿床;④蛇绿岩型矿床。认为小侵入体(小岩体)岩浆矿床是中国主要的矿床类型,并在此基础上,从小岩体矿床的相关概念、3种地质背景、3种火山岩_岩体_矿床组合形式以及成矿的主要因素等方面详细阐述了小岩体成矿作用。结合国内外勘查实践指出,小岩体岩浆矿床仍具有很大的找矿潜力,是中国应继续重点研究的主要矿床类型。最后,还讨论了小岩体矿床不仅在基性_超基性岩体中广泛发育,而且在中酸性岩体中也具有重要的经济价值和研究意义。 相似文献
16.
老代仗沟矿床为伏牛山岩浆期后热液充填成因的脉状铅锌矿的代表性矿床。基于1∶20万和1∶5万水系沉积物地球化学综合异常,开展了1∶1万土壤地球化学测量和1∶5千岩石化探测量。土壤化探次生晕异常(Pb、Zn、Ag成矿元素)的分布面积大、强度高,且与矿带展布方向高度一致;岩石地球化学原生晕异常反映了矿带及矿体的浅、深部的铅锌工业矿体主元素的分布规律,其中Pb、Zn套叠好,Ag、Cu套叠差。矿带由内向外横向分带规律为:Pb-Zn-Ag-Cu→Mn-Sn→(Mo)-Co-Ni;轴向分带自上而下(高程750~450m,间隔60m)为:As-Ag→Sn→Zn-Pb→Be→MoCo-Ni→Cu-Mn;找矿指示元素:矿上为Be、Mn;矿中为Pb、Zn、Ag、(Cu);矿下为Co、Ni。该项研究成果可作为矿带、矿体深部勘查预测的依据。 相似文献
17.
Geology of Ore Deposits - Many massive sulfide ore occurrences and deposits in the Kola region are located within the Paleoproterozoic Pechenga–Imandra–Varzuga rift belt (2.5–1.7... 相似文献
18.
《Ore Geology Reviews》2007,30(3-4):177-241
Australia's nickel sulfide industry has had a fluctuating history since the discovery in 1966 of massive sulfides at Kambalda in the Eastern Goldfields of Western Australia. Periods of buoyant nickel prices and high demand, speculative exploration, and frenetic investment (the ‘nickel boom’ years) have been interspersed by protracted periods of relatively depressed metal prices, exploration inactivity, and low discovery rates. Despite this unpredictable evolution, the industry has had a significant impact on the world nickel scene with Australia having a global resource of nickel metal from sulfide ores of ∼ 12.9 Mt, five world-class deposits (> 1 Mt contained Ni), and a production status of number three after Russia and Canada. More than 90% of the nation's known global resources of nickel metal from sulfide sources were discovered during the relative short period of 1966 to 1973. Australia's nickel sulfide deposits are associated with ultramafic and/or mafic igneous rocks in three major geotectonic settings: (1) Archean komatiites emplaced in rift zones of granite–greenstone belts; (2) Precambrian tholeiitic mafic–ultramafic intrusions emplaced in rift zones of Archean cratons and Proterozoic orogens; and (3) hydrothermal-remobilized deposits of various ages and settings. The komatiitic association is economically by far the most important, accounting for more than 95% of the nation's identified nickel sulfide resources. The ages of Australian komatiitic- and tholeiitic-hosted deposits generally correlate with three major global-scale nickel-metallogenic events at ∼ 3000 Ma, ∼ 2700 Ma, and ∼ 1900 Ma. These events are interpreted to correspond to periods of juvenile crustal growth and the development of large volumes of primitive komatiitic and tholeiitic magmas caused by large-scale mantle overturn and mantle plume activities. There is considerable potential for the further discovery of komatiite-hosted deposits in Archean granite–greenstone terranes including both large, and smaller high-grade (5 to 9% Ni) deposits, that may be enriched in PGEs (2 to 5 g/t), especially where the host ultramafic sequences are poorly exposed.Analysis of the major komatiite provinces of the world reveals that fertile komatiitic sequences are generally of late Archean (∼ 2700 Ma) or Paleoproterozoic (∼ 1900 Ma) age, have dominantly Al-undepleted (Al2O3/TiO2 = 15 to 25) chemical affinities, and often occur with sulfur-bearing country rocks in dynamic high-magma-flux environments, such as compound sheet flows with internal pathways facies (Kambalda-type) or dunitic compound sheet flow facies (Mt Keith-type). Most Precambrian provinces in Australia, particularly the Proterozoic orogenic belts, contain an abundance of sulfur-saturated tholeiitic mafic ± ultramafic intrusions that have not been fully investigated for their potential to host basal Ni–Cu sulfides (Voisey's Bay-type mineralization). The major exploration challenges for finding these deposits are to determine the pre-deformational geometries and younging directions of the intrusions, and to locate structural depressions in the basal contacts and feeder conduits under cover. Stratabound PGE–Ni–Cu ± Cr deposits hosted by large Archean–Proterozoic layered mafic–ultramafic intrusions (Munni Munni, Panton) of tholeiitic affinity have comparable global nickel resources to many komatiite deposits, but low-grades (< 0.2% Ni). There are also hydrothermal nickel sulfide deposits, including the unusual Avebury deposit in western Tasmania, and some potential for ‘Noril'sk-type’ Ni–Cu–PGE deposits associated with major flood basaltic provinces in western and northern Australia. 相似文献
19.
澳大利亚西部伊尔岗克拉通卡尔古利地体是世界上太古宙与科马提岩有关的硫化物镍矿床最为集中的地区。该区科马提岩型硫化镍矿床主要有两大类型：①由高品位的块状、海面陨铁状和网状矿石组成,赋存于科马提岩熔岩流（主要为火山橄榄岩）底部,以卡姆巴尔达矿床为代表;②以低品位的浸染状镍硫化物矿石为主,赋存于厚层纯橄榄岩的中部,以芒特基斯为代表。与镍成矿有关的科马提岩形成于晚太古代（2．70Ga）,具铝不亏损（Al2O3／TiO2=15～25）地球化学特征,一般形成于具含硫围岩的动态高岩浆流环境。伊尔岗克拉通科马提岩型镍硫化物矿床形成于经历岩浆作用（结晶、分异和浓集）和地壳硫混染作用的硫不饱和镁铁质-超镁铁质岩浆的熔岩通道或管道中。在矿床成因讨论的基础上,提出该类型矿床的找矿标志和勘查方法。 相似文献
20.
Liu Xun 《《地质学报》英文版》1990,64(3):261-274
The ore-controlling mechanism of the bedding fault system in the massive sulfide deposits of the Wushancopper orefield may be generalized as the control of ore deposition by optimum surface in an ore-formingstructural trap. The mechanism has three major features: (1) timing of mineralization; (2) positioning of hostformation; and (3) dependence of ore-controlling structure on properties of rocks. The "optimum surface" is adivisional structural plane which marks obvious difference in physical, chemical and mechanical properties andis favorable for mineralization. It is also a unity of structures. lithofacies and orebodies. The structural and geochemical characteristics of the ore deposits indicate the migration trend of the ma-jor characteristic clements in the ore-controlling fault belt: elements with a small radius (Si, Fe, Mg and Al)moved towards and concentrated at the center of the belt while large-radius ones (Ca, K and Na) were remotefrom the center. 相似文献