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太平洋多金属结核中铁锰矿物分析及成因研究 总被引：12，自引：2，他引：10
铁锰矿物是大详多金属结核的重要组成,了解不同类型结核中主要铁锰矿物种类、形态、分布特点和结晶程度等,不仅有助于对锰矿物乃至多金属结核成因的研究,而且对选矿冶炼和资源的综合利用也具有现实意义.本文通过透射电子显微镜等多种手段综合分析与鉴定,指出多金属结核中主要铁锰矿物有钙锰矿、水羟锰矿、水钠锰矿、方锰矿、锰铁矿和针铁矿等.结晶程度普遍较差,钙锰矿结晶相对好于其他矿物,并在粗糙型结核中含量高,外层至核心含量稳定,变化小.水羟锰矿广为分布,但结晶差.铁矿物含量东区低于西区,结核外壳铁含量高于内核.锰矿物分布在叠层石柱体和纹层内,呈束状、纤维状和树枝状,与建造多金属结核的超微生物菌丝体形态一致.粗糙型结核是选冶的主要对象. 相似文献
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为探讨东太平洋CC区多金属结核中富钡镁锰矿细脉蛋白石层的成因机制,利用矿相显微镜、电子探针和ICP-OES,对蛋白石层及其周围铁锰氧化物进行了显微结构特征和化学成分特征的研究。结果表明:高反射率矿物结晶程度较好,主要由MnO组成,具有高Mn低Fe的特征,为成岩成因的钡镁锰矿。中反射率矿物结晶程度较差,主要由MnO和FeO组成,为水成成因的水羟锰矿。低反射率矿物为一种半透明矿物,主要由SiO2组成,为生物成因的蛋白石。根据钡镁锰矿、水羟锰矿和蛋白石的成因机制,为蛋白石层及其内部钡镁锰矿细脉的形成过程建立了一个模型,共分为5个生长阶段:第1阶段,结核呈半埋藏状态在氧化环境中形成水羟锰矿;第2阶段,结核呈半埋藏状态接受SiO2胶体的沉淀作用形成蛋白石层;第3阶段,结核呈半埋藏状态在氧化环境中形成水羟锰矿的同时,其成岩作用和蛋白石的脱水作用使蛋白石层中产生大量的裂缝;第4阶段,结核呈埋藏状态在弱氧化-还原环境中发生交代作用和重结晶作用形成钡镁锰矿;第5阶段,结核呈半埋藏状态形成水羟锰矿。 相似文献
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南海多金属结壳(核)铁锰矿物/海水界面效应与成矿元素的富集 总被引：1，自引：0，他引：1
海底铁锰结壳和结核是重要的海底矿产资源,蕴含着丰富的金属元素并且具有巨大的经济价值。本文主要以南海多金属结壳（核）为研究对象,采用X射线粉晶衍射（XRD）、激光拉曼光谱、红外光谱分析（FTIR）以及X射线光电子能谱对铁锰矿物的矿物学和谱学特征进行了系统的分析和研究。粉晶衍射和拉曼光谱分析结果表明,南海多金属结壳的矿物组成为水羟锰矿、石英和长石,结核的矿物组成为钡镁锰矿、水羟锰矿、石英和长石,铁相矿物均为无定形铁氧化物/氢氧化物,并且锰相矿物和铁相矿物的结晶程度均较差。红外光谱分析结果显示多金属结核和结壳中的铁锰矿物具有大量表面羟基,这些含质子表面羟基官能团,可为海水中各成矿元素的络合提供丰富的活性位点。XPS分析表明多金属结核和结壳中铁锰矿物表面以Fe、Mn和O元素为主,其中Fe呈正三价态,Mn以正四、正三价为主,可能还含有少部分正二价态。对比南海多金属结壳（核）与太平海山结壳,南海多金属结壳（核）具有更为显著的表面羟基氧（-OH）含量,而太平洋海山结壳则以晶格氧（O2-）为主,表明太平洋海山结壳铁锰矿物结晶程度较南海多金属结壳（核）高。综合研究表明,在海底铁锰结壳和结核中（氢）氧化锰/铁矿物与海水之间界面效应对金属离子的富集机理主要有：（1）金属离子与矿物表面羟基进行络合反应,形成以配位键相连的羟基络合物,或与表面的质子交换生成稳定的内层络合物;（2）矿物的带电表面与金属离子通过静电作用形成双电层,生成外层络合物;（3）金属离子与矿物结构中的Mn、Fe离子同晶置换而成为结构阳离子。 相似文献
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采用X射线衍射和微区电子探针法,对2006年"大洋一号"考察船在中太平洋C海山取得的典型富钴结壳样品进行了铁锰矿物的组成和成分特征分析,结果显示:(1)结壳的老壳层中铁锰矿物具有水羟锰矿、钡镁锰矿和钠水锰矿的特征组合,其相对含量分别为45.5%、30.1%和24.4%;中间壳层和年轻壳层中铁锰矿物为水羟锰矿,表明结壳各层生长的环境条件不同.(2)铁锰矿物集合体中Mn/Fe值从老壳层到年轻壳层具有明显降低的趋势,老壳层Mn/Fe值大于20,最高达90;中间壳层Mn/Fe值在2～5之间,年轻壳层Mn/Fe值在1～2之间.铁锰矿物集合体探针测得的结壳老壳层元素的总百分含量稳定在75%左右,中间壳层和年轻壳层为50%～80%.Si、Ti元素含量从老壳层到年轻壳层有增加的趋势,在中间疏松层中百分含量均达到最高值,分别为3.17%和1.53%,表明自老壳层到年轻壳层,碎屑物质或有机质等对结壳的影响程度有增大的趋势.由此可见,研究区富钴结壳主要为水成成因,主要发育了水羟锰矿;老壳层生长期间受到局部海水氧化还原条件变化的影响,铁锰相矿物发生重结晶或重组而形成了水羟锰矿、钡镁锰矿和钠水锰矿特征组合,这种特征铁锰矿物组合的研究对于全面理解海水环境条件变化与结壳成因的关系具有重要的意义. 相似文献
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本文对采自东太平洋CC区的2块不同类型的铁锰结核及中太平洋麦哲伦海山的1块富Co结壳,采用XRD和ICP-MS(AES)等分析研究方法,进行了矿物地球化学的比较研究。结果表明:铁锰结核主要由水羟锰矿及钡镁锰矿组成,富Co结壳主要以水羟锰矿为主。与2块铁锰结核相比,富Co结壳总体上Cu、Al、Na含量较低而Co含量较高;两块不同类型的结核相比较,水成型铁锰结核的P、Ti含量较高,而成岩型铁锰结核的Cu、Ni含量较高。3块样品的稀土元素含量均较高,为(521.8~1 424.15)×10-6。REE分布型式总体呈平缓型,(La/Yb)N为0.72~1.01,并具程度不同的Ce、Eu正异常。经估算,富Co结壳的生长速率为1.92~4.24mm/Ma,水成型铁锰结核的生长速率为1.31~14.29 mm/Ma,成岩型铁锰结核的生长速率为11.24~76.32mm/Ma。并根据铁锰结核的化学成分变化推测了其生长环境的变化。 相似文献
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采用现代方法研究了印度洋和太平洋近赤道生物生产区沉积物中锰质微结核的矿物成分。显示出微结核中矿物相的相互关系与很多因素有关。查明了印度洋中微结核的含铁率与太平洋相比有增大的趋势。推测六方钠水锰矿是锰太物固相变化的终端产物。为了完成这种转化必须要有近４００万年的时间。 相似文献
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由于大洋铁锰结核含有30多种有用的金属元素,是潜在的矿产资源,因而越来越受到人们所重视.关于铁锰结核的矿物组成,国内外学者已有大量的报道.尤其是Piper(1984),Usui(1979)、Burns(1977)等,他们根据各自的分析结果,指出了大洋铁锰结核中的锰矿物主要由1×109m水锰矿δ-MnO2、7×10-10m钠水锰矿及针铁矿组成.并从地球化学、沉积地球化学角度指出了上述矿物的可能成因.然而,由于铁锰结核中锰矿物结晶程度很差和无定形性,用一般手工方法和仪器对单矿物很难分离和辨认.因此,用单一方法来确定某种结核的矿物组成及其相对含量就有一定的困难.为此,我们试用红外光谱分析结合X衍射、电子探针及化学分析结果,探讨红外光谱分析法应用于分析太平洋铁锰结核的矿物组成及结核中Mn含量的可能性. 相似文献
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为探讨富钴结壳中矿物组成对稀土元素分布的制约,对约翰斯顿岛富钴结壳中矿物组成及稀土元素特征进行了研究。依据主要矿物组成,富钴结壳可以分为3种类型,分别命名为A、B、C。由A到C,水羟锰矿含量逐渐降低,B类中磷灰石含量最高,C类中水钠锰矿和钙锰矿含量最高。A类结壳中富集REE3+、Ce,B类结壳中富集Ce和Y。A类富钴结壳中,REE3+、Y以专属吸附的方式富集在铁氧化物上,Ce3+氧化成Ce4+与其他REE分离,吸附在锰矿物上。B类结壳中,稀土元素主要以独立矿物的形式存在,另有部分Ce、LREE3+吸附于铁相中,部分Y存在于磷灰石中。C类结壳中,稀土元素主要赋存在锰矿物中,部分Y存在于磷灰石中。 相似文献
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对大洋27航次在西太平洋马里亚纳海沟挑战者深渊获取的3个多金属氧化物样品进行了X射线矿物衍射分析、穆斯堡尔谱分析及地球化学元素分析,研究其矿物、地球化学特征差异。结果表明,所取样品处于多金属氧化物发育的初始阶段,具有独特的矿物地球化学特征:(1)相较于太平洋CC区及中太平洋海盆获取的多金属结核样品,本研究样品的矿物组成中含有异常高的石英、斜长石以及黏土矿物,而水羟锰矿和钙锰矿含量较低。(2)样品中铁相矿物主要为正方针铁矿(91.6%),另含少量纤铁矿(8.4%),推测是纤铁矿向更加稳定的正方针铁矿衍变的结果。(3)由于样品中深海黏土组分以及氧化物核心物质的混入,加上吸附金属氧化物时间较短,导致SiO2和Al2O3含量均高于正常结核,而Fe、Mn、Cu、Co、Ni等其余金属元素含量较低。(4)由于形成时间较短,样品中稀土元素含量相对较低,ΣREE仅约为0.4×10-3(一般太平洋CC区及中太平洋结核中稀土含量均大于1.0×10-3);加之海水氧化还原作用的降低以及研究区海底热液活动的影响,Ce元素未表现出多金属结核中常见的正异常。 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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Six manganese crusts, 13 manganese nodules, and 16 sediments were analyzed by instrumental neutron activation analysis. Data were generated on selected major and minor elements but geochemical evaluations are based only on Fe, Sc, U, Th, and the rare earth elements (REE). Manganese crusts and manganese nodules have comparable trivalent REE contents and show a shale‐like distribution pattern. Both crusts and nodules are characterized by a positive Ce anomaly but the anomaly is higher in nodules. REE contents in manganese nodules show a linear dependence on the Fe content, and it is concluded that these elements are incorporated in the Fe‐rich (δ‐MnO2) phase. In the crusts, the REE correlate with Sc and are therefore assumed to be associated with the clay minerals. Uranium contents are significantly higher in the crusts than in nodules whereas Th is slightly higher in the nodules. There is a clear positive correlation between U and Th in nodules but there are too few data to make a similar conclusion for crusts. Compositional data suggest a division of the sediments into two groups. The carbonate sediments have much lower REE contents and a more pronounced negative Ce anomaly than the clays, while both show a lithogenous component as indicated by a slight negative Eu anomaly. 相似文献
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C. P. Summerhayes 《新西兰海洋与淡水研究杂志》2013,47(3):267-282
Concentrations of minerals on the sea floor around New Zealand occur in a manner which makes them economically significant as future mineral resources. Three major environments of interest are beaches, the continental shelf, and the adjacent deep‐sea floor. New Zealand's west coast beaches are well known as mineral resources containing large quantities of iron and titanium ores. Similar concentrations representing fossil beaches are also known from the continental shelf. The deep‐sea floor adjacent to the continental shelf is formed around New Zealand by the New Zealand Plateau, an extensive submarine platform in 500–1,500 m. Terrigenous sedimentation is negligible in this environment where, as a result, pure calcareous oozes are common. Vigorous bottom currents and suitable reducing micro‐environments encourage glauconite formation. In the past, possibly from warmer waters of the early and mid Tertiary, phosphates were precipitated from seawater to form phosphorite nodules, a potential resource of phosphates. During late Tertiary or Quaternary, volcanicity at the Antipodes Islands and on the Macquarie Ridge resulted in the formation of manganese deposits. Manganese minerals also occur in bulk on the floor of the Southwestern Pacific Basin away from the New Zealand Plateau. The origin, bulk, and significance of these deposits are discussed. 相似文献
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大洋铁锰结核的微生物成矿过程及其研究进展 总被引：1，自引：1，他引：0
深海铁锰结核作为世界上潜在的巨大金属宝库已成为当今开发海底矿藏的热点，因而深入了解铁锰结核成矿过程成为其开发利用的先决条件。研究发现多金属铁锰结核中的铁锰矿物不仅仅是由单纯的物理作用形成的，同时也包含了海洋生物驱动的生物矿化的过程。本文介绍了运用分子生物学、矿物学和地球化学等多学科的研究方法对大洋中铁锰的生物成矿过程和成矿特征的研究。深海铁锰结核的生长速率缓慢且其生长演化伴随着微生物群落的活动，因此结核的生长过程同时也记录着不同时期微生物群落结构的变化并生成了大量的微生物化石。在铁和锰的生物矿化过程中，细菌可以通过酶促反应氧化Fe（Ⅱ）和Mn（Ⅱ），同时可能伴随生物能量的生成，此外微生物还可以通过非酶促反应的方式促进Fe和Mn的富集沉淀。这些研究表明生物矿化作用在大洋铁锰结核成矿过程中有巨大贡献，对大洋铁锰结核的生物成因过程提供更加全面准确的理解，从而为今后进一步充实大洋铁锰结核的生物矿化理论及其开发利用提供依据。 相似文献
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The contents of oxyanionic elements (V, Se and Mo) and cationic transition metals (Mn, Fe, Co, Ni, Cu and Zn) in sediments from near-shore to deep-sea environments were measured to clarify factors regulating the distribution of these elements in marine sediments. For cationic transition metals of which contents increase from near-shore to deep-sea environments, the chemical composition of pelagic clays is modeled by a mixture of aluminosilicates having the chemical composition of average shale and Fe–Mn oxides having the chemical composition of associated manganese nodules. The content of V is fairly constant in sediments from near-shore to deep-sea areas. The mixture model of average shale and manganese nodules holds also for V, although most of the V is located in the aluminosilicate lattices. The content of Se in the near-shore sediments is higher and that in the deep-sea sediments is lower than that in average shale. The high content in the near-shore sediments is interpreted as the addition of biogenic materials to aluminosilicates with average shale composition and the low content in deep-sea sediments is explained by oxidative release of Se from aluminosilicates. The content of Mo in sediments increases from near-shore to deep-sea environments. The general distribution of Mo in marine sediments is expressed by the mixture model. An anomalously high content of Mo in a near-shore sediment is attributed to adsorption of molybdate on manganese oxides. 相似文献
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洪辉亮 《海洋学报(英文版)》1986,5(4):552-562
No Jess than 90 species of detrital minerals have been identified from the fine and very fine sand grains in the sediments from the Western Central Pacific. It is demonstrated that the volcanic minerals were originated from the eruption of oceanic tholeiitic magma since the Early Pleistocene according to the mineralogical indications and the rare-earth element distribution pattern. The mineral assemblage indicates that the detrital minerals are principally of pelagic origin. But the Melanesia Basin has more terrigenous constituents of minerals, of which, the quartz content increased generally during the interglacial periods. The area of Wallis Islands, especially of the Northern Fiji Basin has relatively typical pelagic substances and less terrigenous components. The genesis of the authigenic manganese nodules is closely related to the brown clay and can also be found in the calcium carbonate sediments in form of fine grain, but not in the relatively loose calciferous volcanic ash bed in the Northern Fi 相似文献
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Heavy minerals with a size range of 0.125～49.250 mm in the surficial sediment of Minjiang Estuary are studied. Thirty-four heavy minerals have been identified, with an average content of 1.92%. Major minerals include magnetite, epidote, hematite, hornblende, ilmenite, and zircon mica. These types are the same as those in the 0.063～0. 125 mm range; however, the average content is lower, which reveals that the heavy minerals in Minjiang Estuary are mainly enriched in the very-fine sand fraction. According to the content and distribution characteristics of the major heavy minerals, Minjiang Estuary can be divided into 4 mineral assemblage zones. In each zone the assemblage of heavy minerals is greatly affected by the hydrodynamic condition and the sedimentary environment. Heavy mineral types also show that detrital matters in Minjiang Estuary are originated from the weathering and erosion of the bedrock in the Minjiang River drainage area. 相似文献
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《Marine Policy》2016
Marine minerals such as manganese nodules, Co-rich ferromanganese crusts, and seafloor massive sulfides are commonly seen as possible future resources that could potentially add to the global raw materials supply. At present, a proper assessment of these resources is not possible due to a severe lack of information regarding their size, distribution, and composition. It is clear, however, that manganese nodules and Co-rich ferromanganese crusts are a vast resource and mining them could have a profound impact on global metal markets, whereas the global resource potential of seafloor massive sulfides appears to be small. These deep-sea mineral commodities are formed by very different geological processes resulting in deposits with distinctly different characteristics. The geological boundary conditions also determine the size of any future mining operations and the area that will be affected by mining. Similarly, the sizes of the most favorable areas that need to be explored for a global resource assessment are also dependent on the geological environment. Size reaches 38 million km2 for manganese nodules, while those for Co-rich crusts (1.7 million km2) and massive sulfides (3.2 million km2) are much smaller. Moreover, different commodities are more abundant in some jurisdictions than in others. While only 19% of the favorable area for manganese nodules lies within the Exclusive Economic Zone of coastal states or is covered by proposals for the extension of the continental shelf, 42% of the favorable areas for massive sulfides and 54% for Co-rich crusts are located in EEZs. 相似文献