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铁锰结壳(又称富钴结壳、多金属结壳)富含Co、Cu、Mn、Ni、Ti、V、REE、Y和Zn等人类日常生活和高新技术产业亟需的关键金属,是一种重要的战略性矿产资源。本文对九州-帕劳海脊南段水深1 900～2 600 m处获得的9个站位铁锰结壳样品进行了矿物学和地球化学研究,分析了铁锰结壳的矿物组成、主微量元素和稀土元素含量,并进一步探讨了铁锰结壳的成因类型。结果表明,研究区铁锰结壳的矿物组成以水羟锰矿为主,同时含有大量非晶态铁氧/氢氧化物;Mn、Fe、Co、Ni、Cu平均含量分别为16.15%、15.38%、0.32%、0.33%、0.10%;CaO/P2O5均值为5.93,表明九州-帕劳海脊南段铁锰结壳样品均未发生磷酸盐化作用;铁锰结壳明显富集稀土元素(含Y,REYs),平均含量为1 194μg/g,轻稀土显著富集,稀土元素经后太古代澳大利亚页岩(PAAS)标准化后配分模式整体相对平坦,呈现Ce正异常而Eu无异常,与海水呈现镜像关系,说明铁锰结壳稀土元素主要来源于海水。铁锰结壳的矿物组成和元素判别图均表明九州-帕劳海脊南段铁锰结壳属于水成型,... 相似文献
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西太平洋麦哲伦海山区是全球重要的铁锰结壳资源分布区,具有丰富的稀土元素资源潜力。本文对采自麦哲伦海山区Kocebu海山的11个铁锰结壳表层样(<1 mm)进行稀土元素地球化学研究,探讨其含量特征、成因和影响稀土元素富集的环境因素。结果表明:Kocebu海山铁锰结壳表层样品ΣREY(Rare earth elements and yttrium)平均含量为1366 mg/kg,低于前人在麦哲伦海山区其他海山以及邻近的马尔库斯–威克海山区的分析结果;样品轻稀土富集和Ce正异常(平均值为1.45)特征以及稀土元素成因图解、配分曲线和分配系数曲线等均表明该海山结壳属于水成成因;海水中稀土元素含量和溶解氧含量是控制结壳生长的关键环境参数,二者在Kocebu海山所在海区的浅水环境中含量较低;结壳ΣREY含量偏低与采样点水深较浅导致的海水稀土元素含量和溶解氧含量较低密切相关,受碎屑矿物的稀释作用影响较小。在开展铁锰结壳地球化学特征研究和资源勘探评价时应充分考虑采样水深的分布范围,局部水深样品的分析结果可能导致研究结果出现较大偏差。 相似文献
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2017年8月中国科学院海洋研究所在西太平洋低纬度海区的卡罗琳洋脊CM4海山开展了多学科综合调查,发现该海山山体表面分布着大量的铁锰结壳。本文对该海山的5个铁锰结壳样品进行了矿物学和地球化学研究,利用X射线衍射(XRD)、电感耦合等离子光谱及质谱(ICP-OES、ICP-MS)等测试技术分析了铁锰结壳的矿物组成、主微量元素和稀土元素含量,并进一步探讨了铁锰结壳的成因类型。结果表明,该海山铁锰结壳的矿物组成以水羟锰矿为主,含有少量钡镁锰矿、水钠锰矿、针铁矿、纤铁矿、石英和方解石。该海山铁锰结壳的Mn、Fe、Co、Ni、Cu元素平均含量分别为24.24%、15.14%、0.16%、0.34%、0.01%。与全球各大洋海山区铁锰结壳相比,该海山样品的Cu含量很低。该海山铁锰结壳的稀土元素(REY)含量相对偏低,总体为轻稀土(LREE)富集;稀土(REY)配分模式显示相对平坦的特征,呈明显的Ce正异常,轻微的Y负异常和Ho正异常。样品的矿物组成、元素比值、元素组合等都表明该海山铁锰结壳属于水成成因,未受明显的成岩作用影响。 相似文献
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铁锰结壳系从大洋水体中直接沉淀而成，水体物理化学条件的变化在结壳内部特征上必然有所反映．因此，在深入理解生长机制与控制因素的基础上，铁锰结壳内部特征可以为恢复古海洋环境演化提供有益信息．结壳中还富集了多种金属元素，是钴、铂等的重要潜在资源． 相似文献
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约翰斯顿岛附近海域铁锰结壳矿物学和地球化学研究 总被引：11，自引：4，他引：11
铁锰结壳存在两种不同的产状，一种是铁锰氧化和的围绕“核心”生长形成的球状结壳，另一种是铁锰氧化物在基底岩石上生长形成的被状结壳。本文对Ｒ／Ｖ，Ｋａｉｍｉｋａｉ－Ｏ－Ｋａｎａｌｏａ船１９９３年１１月在约翰期顿岛附近海域取得铁锰结壳进行了矿物学和地球化学分析。该区铁锰结壳主要组成矿物为δ－ＭｎＯ２，Ｍｎ／Ｆｅ比值为２．０２，富Ｃｏ（０．８８１％），盆Ｃｕ（０．１％），稀土总量（∑ＲＥＥ）１９１８．２７ 相似文献
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太平洋铁锰结壳在中新世以前大多经历了磷酸盐化,一般认为其形成代表了高生产力时期富磷组分对先期已形成结壳的交代作用,即磷酸盐化事件的产物.然而,前人对铁锰结壳磷酸盐化的机制研究多基于点-线分析元素或同位素,对铁锰结壳生长结构及二维元素分布特征研究较少.本研究以西太平洋水成铁锰结壳MDD53为研究对象,利用电子探针(EPM... 相似文献
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广泛分布在大洋海底的铁锰结壳是固体矿产的远景资源。结壳即富含一系列贵金属元素（包括钼），又富集生态学所指的有害元素，尤其是铊和碲。资料显示：结壳中钼和铊含量比沉积岩平均含量高100～120倍，而碲相比高10000倍。因此揭示这三种元素在铁锰结壳中的赋存形式，在地球化学方面和改善此类矿石的开采加工工艺方面，都有现实意义。 相似文献
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太平洋铁锰结壳的锶同位素地球化学研究 总被引：5，自引：0，他引：5
本文研究中太平洋的翰斯顿岛卡林海山铁锰结壳ＲＤ４－２和东太平洋海盆铁锰结壳５４０５的锶同位素组成特征，并利用铁锰结壳的锶同位素组成与大洋海水锶同位素演化标准曲线对比，推断出结壳生长起始年龄、接三元混合模式，计算玄武质组分和硅铝质组分对锶同位素的贡献。 相似文献
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大洋铁锰结壳是继大洋多金属结核之后出现的又一极具潜在经济价值的水下固体矿产(王毅民，1992)，富含Mn、Fe、Cu、Co、Ni和Pt多种金属元素及非金属元素P，Co含量最高可达2.5%，是大陆含Co矿床的数倍到数十倍，铂的平均含量也是上地壳的80倍。据众多科学家的初步估计，仅太平洋西部火山构造隆起带上，铁锰结壳矿床的潜在资源量就达10亿t，其中Co金属含量可达600万～700万t，经济总价值超过1000亿美元(Klinkhammer et al.，1980；Halbach et al.，1984；DeCarlo et al.，1987；何高文等，2001)。这与全球陆地已探明Co资源总量仅为1 500万t相比，数量极为可观，并且结壳的产出水深多小于3000 m， 易于进行系统的、大量的样品采集，开采风险及开采时对环境的影响也较小。因此，近年来，随着世界经济的蓬勃发展和高新技术的开发， 对Mn、Cu、Co、Ni等元素的需求日益增大及由此所导致的陆地上这些资源的迅速枯竭，使人们纷纷将目光转向深海底矿产，加大了对海底铁锰结壳资源的研究力度和深度，其资源的经济地位也相应进一步提高。据专家预测，大洋铁锰结壳很可能会比大洋的金属结核率先实现商业性开采，并成为21世纪新兴的海洋矿产产业(Hein et al.，1998；潘家华等，1995)。
此外，结壳还有净化空气中SO2与NO2的氧化催化剂等用途，并且铁锰结壳成矿环境的研究，还具有较高的科学价值，可使科学家进一步深入了解和认识地内深部物源、海底水-岩反应、金属成矿富集过程及其中的微生物成矿作用乃至古海洋环境演变等问题，而这些问题迄今仍未得到完善解决，是当前地学和海洋学领域的研究热点。这就使铁锰结壳成矿环境的研究显得尤为重要。 相似文献
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Ｔｒａｎｓｆｅｒｏｆｍａｎｇａｎｅｓｅａｎｄｆｅｒｒｏｉｏｎｓｂｙｍａｎｇａｎｅｓｅｂａｃｔｅｒｉａ￥ＳｈｉＪｕｎｘｉａｎａｎｄＣｈｅｎＺｈｏｎｇｙｕａｎ（ＴｈｅＳｅｃｏｎｄｉｎｓｔｉｔｕｔｅｏｆＯｃｅａｎｏｇｒａｐｈｙ，ＳｔａｔｅＯｃｅａｎｉｃＡｄ... 相似文献
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麦哲伦海山区MD、ME、MF海山富钴结壳特征 总被引：10，自引：0，他引：10
麦哲化海山区MD、ME、MF海山具有三层构造的结壳特征，研究表明，结壳可分为上部较致密层、中部疏松层、下部致密层。致密层构造单一，含很少脉石矿物；疏松层构造杂乱，含有大量脉石矿物；较致密层介于两者之间，壳层矿物有锰相矿物（主要为水羟锰矿）、铁相矿物和次要矿物（粘土矿物、钙十字沸石、石英、方解石、磷灰石等）。不同壳层地球化学特征具有明显差异性，Ce异常表明在结壳从下层到上层的生长过程中，环境的氧化性逐渐减弱，结壳^10Be测年结果表明，疏松层的生长速率最大，其次为致密层，较致密层的生长速率最小。推测区的最老的结壳的生长年代为中新世晚期，在4Ma以前，区内水动力条件很弱，氧化性较强；4－3．1MaBP水动力条件较强，氧化性较弱；2．6MaBP以来，水动力条件为强－弱波动期，氧化性较弱。 相似文献
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过渡金属元素Cu、Co、Ni在铁锰结核(壳)中富集的控制因素 总被引：7，自引：0，他引：7
在不同生成环境下生成的铁锰结核(壳)吸收不同的过渡金属元素。在成岩作用形成的铁锰结核中,Cu、Ni主要以锰相形式存在,而Co则以铁相的形式存在;在水成作用形成的铁锰结核(壳)中Cu、Co、Ni均以锰相的形式存在。这些过渡金属元素在成岩作用形成的结核中的存在与铁锰结核(壳)中锰矿物和铁的氧化物、氢氧化物的晶体化学特征密切相关,而在水成作用形成的铁锰结核(壳)中的富集与锰矿物和铁的氧化物、氢氧化物的晶体化。学特征关系不大。同时铁锰结核(壳)中锰矿物和铁的氧化物、氢氧化物又严格地受结核(壳)的生成环境的制约,因此,过渡金属元素Cu、Co、Ni在铁锰结核(壳)中的富集在一定程度上受结核(壳)生成环境的控制。 相似文献
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Gravity and multichannel seismic reflection constraints on the lithospheric structure of the Canary Swell 总被引：1，自引：0，他引：1
Deep penetrating multichannel seismic reflection and gravity data have been used to study the lithospheric structure of the Canary Swell. The seismic reflection data show the transition from undisturbed Jurassic oceanic crust, away from the Canary Islands, to an area of ocean crust strongly modified by the Canary volcanism (ACV). Outside the ACV the seismic records image a well layered sedimentary cover, underlined by a bright reflection from the top of the igneous basement and also relatively continuous reflections from the base of the crust. In the ACV the definition of the boundary between sedimentary cover and igneous basement and the crust-mantle boundary remains very loose. Two-dimensional gravity modelling in the area outside the influence of the Canary volcanism, where the reflection data constrain the structure of the ocean crust, suggests a thinning of the lithosphere. The base of the lithosphere rises from 100 km, about 400 km west of the ACV, to 80 km at the outer limit of the ACV. In addition, depth conversion of the seismic reflection data and unloading of the sediments indicate the presence of a regional depth anomaly of an extension similar to the lithospheric thinning inferred from gravity modelling. The depth anomaly associated with the swell, after correction for sediment weight, is about 500 m. We interpret the lithospheric thinning as an indication of reheating of old Mesozoic lithosphere beneath the Canary Basin and along with the depth anomaly as indicating a thermal rejuvenation of the lithosphere. We suggest that the most likely origin for the Canary Islands is a hot spot. 相似文献
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Norikazu Kinoshita Yuko Sato Takeyasu Yamagata Hisao Nagai Akihiko Yokoyama Takashi Nakanishi 《Journal of Oceanography》2007,63(5):813-820
In order to estimate the deposition rate of extraterrestrial material onto a manganese crust in a search for supernova debris,
we analyzed the contents of 10Be, 230Th, 231Pa, and 239,240Pu in a sample of manganese crust collected from the North Pacific Ocean. On the basis of the depth profile of 10Be, the growth rate of the manganese crust was determined to be 2.3 mm Myr−1. The uptake rates of 10Be, 230Th, and 231Pa onto the manganese crust were estimated to be 0.22–0.44%, 0.11–0.73%, and 1.4–4.5%, respectively, as compared to the deposition
rates onto the deep-sea sediments near the sampling station, while that for 239,240Pu was 0.14% as compared to the total inventory of seawater and sediment column. Assuming that sinking particles represent
0.11–4.5% of the uptake rates, the deposition rate of extraterrestrial material onto the manganese crust was estimated to
be 2–800 μg cm−2Myr−1 according to the uptake of 10Be onto the manganese crust. Further, our estimate is similar to the value of 9–90 μg cm− 2Myr−1 obtained using the integrated global production rate of 10Be and the deposition rate of 10Be onto the manganese crust. 相似文献
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The manganese crust covered by pelagic sediment was recovered from the 3 km depth from the Peterbourgskoye ore field located on the eastern flank of the Mid-Atlantic Ridge. The crust comprises a platy brittle aggregate 1–5 cm thick made of black heterogeneous and partly porous material. The inner structure consists of aggregated parallel microplaits several micrometers to 0.2 mm thick consisting of well-crystallized bisnessite with a minor admixture of colloform vernadite. The chemical composition of the crust is dominated by manganese (more than 60% MnO) with minor iron (1.7% Fe2O3) and somewhat notable sodium and sulfur. The trace element composition is characterized by very high molybdenum, moderate gallium and uranium, and very low values of 40 other trace elements. Compared to previous publications, the composition of this crust is fairly different from the average values previously defined for hydrothermal crusts. On the other hand, it is rather close to some crusts recovered from subsea volcanoes in the Sea of Japan. 相似文献
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Carles Canet Rosa María Prol-Ledesma William L. Bandy Peter Schaaf Carlos Linares Antoni Camprubí Esperana Tauler Carlos Mortera-Gutirrez 《Marine Geology》2008,251(1-2):47-59
Marine hydrogenetically precipitated ferromanganese crusts are widespread in the Pacific Ocean. They occur as pavements coating volcanic or sedimentary hard-rock substrates, mainly on the slopes of seamounts, plateaus and hills in ocean basins and continental margins. We studied three ferromanganese crusts from one dredge haul from the Rivera Plate (western margin of Mexico), which are up to 15 mm thick and grow directly on a substrate of pillow basalt fragments. They consist of laminated, botryoidal, porous aggregates mostly of Fe and Mn oxyhydroxides and up to 10% silicates. XRD analysis showed the predominance of poorly crystallized mineral phases in the crusts that include Mn-feroxyhyte and vernadite, and an authigenic smectite-like clay. Detrital minerals probably derive from granodiorites of the eastern wall of the neighboring Middle America Trench. Scattered barite grains occur on the crust surface and suggest plume fall-out derived from hydrothermal vents, although a possible pelagic source cannot be dismissed. Ratios between major (Fe, Mn, Si) and trace (Co, Ni, Cu) elements reveal that such crusts are predominantly hydrogenetic in origin, although they show a hydrothermal influence that increases in the outer layers. Iron contents range from 16.2 to 25.2 wt.%, and manganese from 3.4 to 14.5 wt.%. The Fe/Mn ratio ranges from 1.6 to 7.0. The SiO2/Al2O3 ratio ranges from 4.3 to 6.6, indicating the presence of biogenic silica (radiolarians). The concentrations of copper (up to 383 ppm) and cobalt (up to 534 ppm) are significantly below those of the typical hydrogenetic crusts, whereas Ni (up to 1320 ppm) is about the same or slightly lower. REE normalized profiles and ΣREE values (486 to 732 ppm) match those reported for hydrogenetic crusts, but suggest a hydrothermal contribution for the later crust layers. The inferred crust growth rates using the Co-chronometer (44 and 229 mm/Myr) are higher than those reported for pure hydrogenetic crusts (mostly 1 to 6 mm/Myr), thus indicating an increasing hydrothermal influence. The highest growth rate (229 mm/Myr, corresponding to the outer crust layers) suggests a regional hydrothermal input of iron and manganese to seawater. The intensification of regional submarine hydrothermal activity began about 13,000 yr ago, and may be related to the tectonic activity in the complex junction of the Rivera, Cocos, Pacific and North America plates. 相似文献
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Morphological Features of Co-Rich Manganese Deposits and Their Relation to Seabed Slopes 总被引：7，自引：0，他引：7
The morphological features associated with Co-rich manganese deposits, the size variations of nodules, and the occurrence of different substrates have been analyzed, to evaluate the influence of various seabed slope angles on the distribution of these features. The coverage and size of the crusts depend on their surface morphology and seabed topography, resulting in cobble-type, lineated, or step-like outcrops. Small nodules (1 - 4 cm in diameter) dominate all seabed slopes, with a few locations having nodules ranging from 1 to 8 or 1 to 10 cm. Sediments invariably occur as substrates for nodules and as cover for crusts, their coverage being inversely proportional to that of the nodules and crust outcrops. Steeper seafloor areas have large crust outcrops exposed with no or few nodules and sediments associated with them. The intermediate slopes have a combination of nodules, sediments, and crusts in various proportions, depending on topography and gradient. Large-scale nodule occurrences, followed by sediment fields and crust outcrops on seabed slopes of greater than 3 degrees, 3 - 7 degreees, and less than 15 degrees, respectively, represent typical morphological distribution zones of the Co-rich manganese deposits on a seamount in the central Pacific Ocean. A transition zone between nodule-dominated fields and large crust outcrops occurs for slopes from 7 degrees to 15 degrees. This detailed study on distribution of Co-rich deposits gives a better understanding for purposes of their exploitation. 相似文献
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The past 20 years have been characterised by limited interest in the economic viability of deep seabed mining with the exception of those mineral ores rich in precious metals such as polymetallic sulphides. This paper goes against the tide. After reviewing the most significant literature, it compares the economic feasibility of mining polymetallic manganese nodules and cobalt-rich ferromanganese crusts in a scenario of mutual exclusivity. It uses a new indicator, the cobalt-nickel price ratio, whose aim is to verify at what metal prices the net present value of the two mining projects equalises. Previous research has shown that the turning margin between manganese nodules and cobalt crusts is a cobalt price of $50/kg. The present paper revises this by showing that the choice between mining crust and nodules depends on fluctuations in the price of nickel. A Monte Carlo simulation proves that cobalt crust mining could be reasonably preferred to manganese nodules at cobalt prices of $40-60/kg if the price of nickel fell below $11/kg. Within this condition, investors would receive the minimum acceptable internal rate of return of 15%, which is at a level of risk closer to the land-based mining. However, when the price of nickel passes the $11/kg threshold, the equilibrium between the two ventures can be reached only at a cobalt price greater than $100/kg, causing cobalt crust to become uncompetitive. Finally, the paper, recognising that prices are not unique drivers, introduces legal, political, technological and environmental concerns to show that the final choice between the two mining ventures cannot be merely driven by economic issues. 相似文献