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菲律宾AREA矿区红土镍矿为硫化镍矿岩体风化-淋滤-沉积形成的地表风化壳型矿床,矿体赋存在含矿风化基岩中。为圈定该矿区红土镍矿有利地段,依据岩(矿)石物性特征、矿体地质特征,采用对称四极电阻率剖面法(简称对称四极法)面积性测量,发现低阻异常;利用高密度电阻率测深法(简称高密度电法)剖面,对成矿有利地段进行评价并确定含矿层厚度和产状,圈定镍矿富集部位。工程验证结果表明,见矿较好位置与电法结果吻合较好。研究结果表明,红土镍矿勘探在前期工作中,采用电阻率法可圈定含矿层范围和延伸产状,有效缩小勘探范围,指导工程勘探布置,节约勘探成本。 相似文献
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东南亚地区红土型镍矿分布较广,成矿地质条件优越。该类矿床产于超基性岩带顶部红土型风化壳内,矿石多为含镍的褐铁矿化黏土,其产出规模、分布范围和品位高低与原岩类型、气候变化、地形地貌和构造条件关系密切。成矿物质主要来源于超基性岩体,是镁铁质-超镁铁质岩体风化-淋滤-淀积的产物,矿石的矿物组分与风化土的矿物组分大体一致,属黏土硅酸盐镍矿床。本文在收集前人资料的基础上,系统地阐述了矿床区域地质背景、矿床地质特征及成矿分布规律初步研究,总结出了该类矿区找矿标志及成矿规律,对寻找红土型镍矿床具有一定的指导作用。 相似文献
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菲律宾迪纳加特岛红土型镍矿床地质特征及找矿勘查方法 总被引：1，自引：0，他引：1
通过对菲律宾迪纳加特岛风化壳氧化镍-硅酸镍矿床的成矿地质条件、矿床地质特征、成矿机制的分析和研究,认为矿床是由于超镁铁岩-橄榄岩在中生代、第三纪、第四纪的热带、亚热带气候条件下,经过风化作用,镍从含镍的硅酸盐矿物中淋滤出来,随地表水向下渗透到风化壳的下部,形成富含镍的次生矿物,具有典型的风化壳型硅酸镍矿床特点。找矿勘探工作要在找矿区域进行地质填图及工程取样扫面来确定矿化区。 相似文献
4.
中国主要镍矿类型及其与古板块构造的关系 总被引：3，自引：1，他引：3
新中国成立后,开展了大规模持续的地质找矿工作,发现了一系列镍矿床。这些矿床的探明,充分证实我国是一个镍矿资源十分丰富的国家。本文在归纳划分了镍矿类型之后,试图对在古板块构造作用下镍矿区域成矿问题作些探讨。主要依据现代海洋资料建立起来的板块构造学说,生动而又精辟地阐述了晚近地质时期某些地质构造规律和成矿作用。但是,对于古板块构造作用和受古板块制约的古成矿作用来 相似文献
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缅甸达贡山风化壳型硅酸镍矿床 总被引：2，自引：0，他引：2
矿床产于超基性岩顶部的风化壳硅镁镍矿层中,超基性岩方辉橄榄岩是成矿母岩和矿体直接载体。矿石为硅酸镍氧化矿石,镍以类质同象存在于硅酸盐矿物中。具有典型的风化壳型硅酸镍矿床特点。 相似文献
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W. Schellmann 《Mineralium Deposita》1989,24(3):161-168
The recently discovered lateritic nickel ore deposit on the summit area of the Tagaung Taung contains about 40 million DMT nickel-saprolite ore with approximately 2% Ni. The serpentinite massif is covered with a thick weathering mantle consisting of saprolite, limonite, and an allochthonous lateritic surface layer. The thickness, nickel content, and physical properties of the ore are very variable. The main minerals in the nickel saprolite ore are nickeliferous serpentine and smectite. Microprobe analyses show a strong depletion of Mg with increasing nickel content in the serpentine minerals; smectite generally contains less nickel than serpentine. Chemical analyses of samples from more than 100 drill holes are used to calculate the mean chemical compositions, mean accumulation factors, and gain and loss of major and trace elements for the various layers. This permits a quantitative approach to be made to the genetic history of the weathering mantle. Gain and loss determinations on the basis of constant chromium content and of constant volume give nearly identical results for the saprolite layer. Calculations on the basis of Ni/Cr ratios indicate that three-quarters of a former 20-m-thick limonite layer has been eroded away. Only the lower part of the original limonite layer with a relatively high SiO2 content is preserved. The kaolinite- and illite-rich surface layer is a mixture of limonite and weathered clayey material, which was probably derived from adjacent rocks. Part of the autochthonous weathering section is contaminated with infiltrated allochthonous surface material. It is not possible that colluvial-alluvial deposition of clayey material from nonultramafic rocks could have taken place under the present geomorphic regime. Thus, lateritization of the serpentinite and deposition of siallitic material must have occurred before exposure of the Tagaung Taung in its present form. 相似文献
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Kolonodale矿床是东南亚红土镍矿带上一处典型矿床,位于印度尼西亚苏拉威西岛东部。矿床产自富镁超基性岩红土风化壳,矿化剖面自上而下出现红土层→腐岩层→基岩层垂向分带。红土镍矿石产在红土剖面上部,载镍矿物是铁质氧化物。硅镁镍矿石产在红土剖面中下部,载镍矿物为镍蛇纹石、镍滑石等含水层状硅酸盐矿物。地球化学分析显示,沿矿化剖面元素地球化学分异非常显著,Ni次生富集效应明显。超基性岩红土化过程的元素地球化学行为具有多样性,Fe、Al、Ti、Cr属残留富集组分,Si、Mg属淋滤缺失组分,Mn、Ca、Co、Ni属次生富集组分。通过典型矿床对比,Kolonodale矿床属原地自生硅酸盐型红土镍矿床,其发育受地质背景和地表环境条件的综合制约。富镁超基性岩、良好的构造组合、稳定的大地构造环境、湿热热带雨林气候、有利地形地貌等均是成矿有利条件。综合分析认为,Kolonodale矿床的成矿过程可划分为腐岩化、红土化和次生富集3个成矿阶段。 相似文献
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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
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Kolonodale矿床是东南亚红土镍矿带上一处典型矿床,位于印度尼西亚苏拉威西岛东部。矿床产自富镁超基性岩红土风化壳,矿化剖面自上而下出现红土层→腐岩层→基岩层垂向分带。红土镍矿石产在红土剖面上部,载镍矿物是铁质氧化物。硅镁镍矿石产在红土剖面中下部,载镍矿物为镍蛇纹石、镍滑石等含水层状硅酸盐矿物。地球化学分析显示,沿矿化剖面元素地球化学分异非常显著,Ni次生富集效应明显。超基性岩红土化过程的元素地球化学行为具有多样性,Fe、Al、Ti、Cr属残留富集组分,Si、Mg属淋滤缺失组分,Mn、Ca、Co、Ni属次生富集组分。通过典型矿床对比,Kolonodale矿床属原地自生硅酸盐型红土镍矿床,其发育受地质背景和地表环境条件的综合制约。富镁超基性岩、良好的构造组合、稳定的大地构造环境、湿热热带雨林气候、有利地形地貌等均是成矿有利条件。综合分析认为,Kolonodale矿床的成矿过程可划分为腐岩化、红土化和次生富集3个成矿阶段。 相似文献
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The Bitincke nickel laterite deposit, located in the south east of Albania, contains an estimated ore resource of 35.6?Mt of nickel ore with a grade of 1.2?% Ni. The deposit developed on peridotites within Late Jurassic ophiolites which were obducted in the Early Cretaceous and which form part of the Albanian Mirdita ophiolite zone. Limestones and conglomerates overlying the deposit delimit the minimum age of lateritization to the mid-Eocene. The laterite is composed of two distinct ore zones characterized by silicate nickel and iron oxide phases. Within the silicate zone, Ni concentrations reach a maximum of 1.5?wt% and although laterally and vertically variable this zone is typically characterized by olivine and serpentine at the base of the horizon which are gradually replaced by secondary silicates and iron oxides up section. The boundary between the silicate and the oxide zone above is normally sharp and characterized by an increase in Fe2O3 (from ~10 to 80?wt%), decreases in SiO2 (from ~30 to 5?wt%) and a dramatic reduction in MgO content (from ~10 to 0.1?wt%). The oxide horizon is dominated by goethite and displays relatively little variation in textural morphology or geochemistry. Nickel concentrations are greatest near the base of this zone, reaching a maximum of 2.3?wt%. Weathering profile formation and variation in the thickness of the deposit was controlled by the interaction between topography, faulting and protolith fracture density. The oxide zone formed on topographic highs was subject to increased rates of erosion, whereas the laterite profile within topographic lows, and in areas of relatively high fracture density, tends to be thicker due to increased permeability. The most substantive sections of the Ni laterite weathering profile developed in small fault controlled basins and were preserved by the deposition of a sequence of limestones and mudstones. 相似文献
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M.R. Thornber 《Chemical Geology》1975,15(1):1-14
An electrochemical model for the weathering of massive sulphide deposits that have undergone conditions similar to those affecting the Kambalda nickel deposits is presented. Galvanic corrosion due to aeration of the top of the ore body near the water table results in a deep anodic reaction whereby primary sulphides undergo an oxidative transition to sulphur-rich violarite—pyrite ore and also a shallow oxidative anodic reaction where the violarite—pyrite ore is oxidised to sulphate and gossanous oxides. Electrons are conducted through the ore from the anodes to the cathode where dissolved oxygen radicals are reduced and the corrosion cells are completed by ionic transport through the groundwaters to the anodic regions that can be some 200 m deep in the case of deep weathering processes. The kinetics of the weathering are described in terms of resistance to the flow of corrosion currents in the electrochemical cells. The effect on the model of physical perturbations such as rising and falling water table, faulting, etc. is discussed. 相似文献
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中国镍矿成矿规律初探 总被引：12，自引：0，他引：12
我国镍矿可分为岩浆型、海相沉积型和风化壳型3种预测类型.矿床形成时代较为连续,最早形成于中—新元古代,最晚形成于新生代,其中中—新元古代和晚古生代是形成矿床的两个高峰期;中—新元古代矿床主要分布在华北地块和扬子地块周缘,晚古生代镍矿主要分布在中亚造山带、峨眉山和塔里木大火成岩省范围内.岩浆型镍矿主要形成于大陆边缘裂解、造山带后碰撞伸展以及地幔柱3种构造背景,根据不同构造背景并结合主要岩浆作用特点,将与幔源基性—超基性岩有关的镍-铜-钴-铂族元素矿床成矿系列类型划分出与大陆裂解边缘幔源基性—超基性岩浆作用有关的镍-铜-钴-铂族元素矿床成矿亚类型、与地幔柱基性—超基性岩浆作用有关的镍-铜-钴-铂族元素矿床成矿亚类型、与造山带俯冲作用下幔源基性—超基性岩有关的镍-铜-钴-铂族元素矿床成矿亚类型、与造山带后碰撞伸展背景下幔源基性—超基性岩有关的镍-铜-钴-铂族元素矿床成矿亚类型等4种亚类型.分别对中—新元古代与大陆边缘裂解有关的镍铜(铂)矿床、寒武纪与黑色页岩有关的海相沉积型镍钼钒矿床、早二叠世与造山带伸展背景有关的镍铜矿床、晚二叠世与大火成岩省有关的镍铜(铂)矿床、新生代与风化壳有关的镍金矿床及其对应的典型矿床特征和成矿模式进行了叙述;认为大陆裂解边缘、地幔柱、造山带后碰撞伸展是我国镍矿形成的有利成矿地质背景,与邻近深大断裂、镁铁—超镁铁岩体、高MgO的原生岩浆(高镁玄武质岩浆)、深部岩浆作用、硫饱和与硫化物熔离共同组成岩浆型镍矿的6个重要地质条件. 相似文献
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川西冕宁-德昌REE矿带中的风化型矿石研究相对缺乏.根据近几年的野外地质调查,采用电子探针、X光粉晶衍射、全岩分析等对大陆槽、牦牛坪和木落寨矿床中疑似风化矿的样品进行类型和成因分析.结果表明:大陆槽风化型矿石中大量粘土矿物（达40%）和矿石矿物（达60%）发育,风化程度高;相反,牦牛坪和木落寨疑似风化型矿石中几乎没有粘土矿物,风化程度低.通过对牦牛坪和木落寨疑似风化型矿石进行地球化学特征、矿物组成分析并与围岩、矿脉的组成和产状对比,表明疑似风化型矿石主要是由矿脉和围岩在强烈的构造作用下发生机械风化形成.频繁的角砾构造使大陆槽矿石发生强烈的机械风化作用,并加速了矿石发生一定的水岩反应,促进矿石发生中等强度的化学风化作用.目前整个矿带中未发现明显的生物风化作用.整个稀土矿带的风化型矿石比南岭离子吸附型稀土矿石的风化程度低,形成时间较晚（11 Ma）,氟碳铈矿大量保存,还没有形成离子吸附型矿床. 相似文献
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A. M. S. Clark 《Mineralium Deposita》1978,13(2):221-234
The Sidamo serpentinites have developed by metamorphism of alpine-type peridotites and have been metamorphosed to talc schists, tremolite-chlorite schists and actinolite schists. Magnesite replacement, and opal and chalcedony veining result from weathering, though some magnesia and silica may have formed during metamorphism. Nickel concentration was negligible during metamorphism, but occurred to a significant extent during soil formation to form nickeliferous lateritic soils. Unfortunately most of the Sidamo serpentinites are undergoing high erosion (steep sided hills) and/or slow weathering (arid climate), so that soil formation and nickel concentration is poor. 相似文献
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红土型镍矿是基性、超基性岩在热带、亚热带地区常年高温、多雨的环境下,经过风化--淋滤--沉积富集而成。基性、超基性岩是此类矿床的成矿母岩。因此,以往针对红土型镍矿的找矿勘探首先是寻找基性、超基性岩。笔者近期在印度尼西亚苏拉威西省Kolaka县发现了一种新型红土镍矿床,该矿床成矿母岩并非是基性、超基性岩,而是砾石成分以超基性岩为主的一套砾岩。为了区分传统意义上由基性、超基性岩风化淋滤形成的红土型镍矿,笔者将其称为砾岩型红土镍矿。该矿床的结构分带由上往下可分为:腐植土层、红土层、强风化砾岩层、半风化砾岩层、砾岩层,镍矿体主要分布于半风化砾岩层中。初步认为矿床是由砾岩经过风化--水解-淋滤-沉淀富集等作用形成的。 相似文献
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渤海湾盆地海域太古代-古元古代片麻岩潜山分布面积巨大,已发现多个油气田,有重要勘探价值。本文综合应用岩心、铸体薄片、X衍射、扫描电镜、常规物性、锆石测年、矿物溶蚀模拟等实验手段及统计分析方法落实了渤海片麻岩风化壳型储层地质特征、成因机理及发育模式。研究表明,片麻岩中长英质矿物含量大于70%有利于形成潜山裂缝型优质储层;大气水风化淋滤作用对长石类矿物的溶蚀,形成大量次生孔隙和沿裂缝的溶蚀扩大孔隙,极大改善了片麻岩潜山的储层物性;构造作用产生的断裂和节理不仅可以直接提供储集空间,还可以作为渗流通道加大风化淋滤作用的影响深度和范围,促进深部岩石的溶蚀改造,加速风化过程。上述主控因素指导下建立自上往下发育粘土带、砂化带、砂化砾石带、裂缝带和基岩带的片麻岩风化壳型潜山储层发育模式。 相似文献
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荥巩煤田大峪沟矿段深部铝土矿床是最近找矿突破发现的一个大型铝土矿床。该铝土矿床成矿时代为早二叠世,成矿物源主要为古陆铝硅酸岩风化物,少量为中奥陶统马家沟组碳酸盐岩风化产物,成矿环境为潮坪-沼泽环境,由长期的沉积间断、特定的岩相古地理环境、构造变形和表生风化作用共同控制着矿床的形成;上石炭统本溪组是铝土矿形成的含矿岩系;海湾泻湖相沉积环境是铝土矿床形成的有利条件;下古生界奥陶系、寒武系古岩溶侵蚀面是铝土矿形成的有利场所,古岩溶侵蚀面洼地及漏斗是铝土矿的定位空间。大峪沟矿段铝土矿床成因模式属于"古陆风化+碎屑和化学沉积";成矿机制为机械和化学分异。含矿岩系底部铁质风化壳/铁质黏土岩为碳酸盐岩风化形成,铝(黏)土矿来源于铝硅酸盐岩。大峪沟深部铝土矿床的发现为河南省寻找深部铝土矿床指明了方向。 相似文献