海山富钴结壳的圈矿方法

对海山富钴结壳的圈矿方法进行了分析和探讨,指出海山富钴结壳圈矿的主要方法和步骤为:(1)挑选富钴结壳发育良好的海山。除大片连续厚层板状分布的结壳发育良好的大型平顶海山是重点调查的目标海山外,规模较小的尖顶海山是近年来新的圈矿目标海山。(2)确定矿块的边界位置。对选定的海山进行深海摄像、电视抓斗、拖网和浅钻等多种手段的调查,通过所取得的综合结果对矿块边界进行判断,确定准确的矿块边界。(3)计算结壳的覆盖率。利用调查所获得的矿块相关的数据和信息对矿块内结壳厚度和结壳覆盖率以及矿区资源量进行评估。     

全球三大洋海山钴结壳资源量估算

钴结壳具有Co、Ni、Cu和Mn及其他金属的潜在矿产资源和储存在结壳层中古环境信息的双重意义。与深海多金属结核和热液硫化物矿床相比,具有较高Co、Ni和Pt含量的海山钴结壳有可能成为商业勘探的潜在目标。为合理地估算出全球三大洋海山钴结壳资源量,基于我国西太平洋海山钴结壳拖网采样调查资料和对太平洋海山钴结壳资源分布规律和钴结壳矿区圈定参数指标的深入研究,按海山不同高度、不同洋壳年龄赋予不同结壳厚度,进而计算出全球三大洋海山钴结壳分布面积为3 039 452.14km2和干结壳资源量为(1 081.166 1~2 162.332 2)×108 t。太平洋海山钴结壳分布面积为2 123 087.12km2和干结壳资源量为(513.244~1 026.488)×108 t,大西洋海山钴结壳分布面积为512 509.74km2和干结壳资源量为(116.503 2~233.006 4)×108 t,印度洋海山钴结壳分布面积为403 855.28km2和干结壳资源量为(81.484 9~162.969 8)×108 t。三大洋海山钴结壳的Mn、Co、Ni和Cu金属量分别为(138.848 0~277.696 0)×108 t,(3.967 6~7.935 2)×108 t、(2.793 6~5.587 2)×108 t和(0.825 1~1.650 2)×108 t。根据钴结壳的Co含量、Co通量和厚度相关分析,所赋予的钴结壳厚度占理论推测厚度的6.10%~12.20%,这与Ku等得出"钴结壳生长时间约占其整个生命史4%"的认识非常相近。三大洋海山钴结壳实测厚度与赋值厚度对比分析表明,太平洋海山钴结壳赋值厚度平均值为1.87cm,实测厚度平均值为1.77cm,相对误差为5.35%,大西洋和印度洋相对误差分别为18.18%和23.23%。研究数据表明按海山高度和洋壳年龄所赋的钴结壳厚度基本合理,估算出的钴结壳资源量基本可靠。本文首次估算出三大洋海山钴结壳资源量,为整个海盆和三大洋海山钴结壳资源量估算提供了新方法。     

中西太平洋海山形态类型与钴结壳资源分布关系

通过对中西太平洋海山形态剖面的山体高度、山顶直径、基底直径、山顶直径与基底直径之比、山体坡度、山体高度与基底直径比值六个参数多元统计分析,发现可以根据山体高度与基底直径的比值对海山形态类型进行分类:比值小于0.10的为平顶海山(Ⅰ类),大于0.10的为尖顶海山(Ⅱ类),对于等于0.10的海山需参考平坦度和山体坡度,平坦度大和山体坡度缓的为Ⅰ类,反之为Ⅱ类。西太平洋的麦哲伦海山区、马绍尔群岛基本以平顶海山为主,介于中西太平洋之间的威克—马尔库斯海山区和中太平洋海山区、莱恩群岛平顶海山与尖顶海山共同发育。对各种类型海山上钴结壳分布研究发现,无论是在尖顶海山还是在平顶海山,板状结壳均比较发育,但砾状结壳在平顶海山比在尖顶海山的发育。中太平洋尖顶海山的结壳比平顶海山的发育,但由于山顶面积小,钴结壳资源量不大。仅从平顶海山看,在麦哲伦海山区、威克—马尔库斯海山区板状结壳比中太平洋海山区、马绍尔群岛、莱恩群岛的板状结壳发育,前者的板状结壳平均厚度大于3 cm,后者的板状结壳平均厚度小于3 cm,总体上是西太平洋平顶海山钴结壳比中太平洋平顶海山的发育。两种类型海山各方向上的资源分布明显不同,在平顶海山的西部山坡的资源比东部山坡的丰富,尖顶海山的则刚好相反。     

基于 GIS 的富钴结壳资源量计算系统开发

富钴结壳资源量计算和资源评价是大洋富钴结壳矿区圈定工作的重要内容之一。阐述了基于GIS组件MO构建富钴结壳资源量计算系统的主要功能模块组成和设计思路。该系统利用VC采取面向对象的方法编程,设计开发了富钴结壳资源量计算评价程序,实现了地质块段法等多种计算方法。该系统吸纳了资源评价和矿区圈定中水深、丰度、品位和坡度等几个重要评价指标,可方便地实现钴结壳资源量计算,为大洋富钴结壳矿区圈定和矿产资源开发提供依据和参考。     

中太平洋海山区尖顶和平顶海山结壳成矿与分布的比对研究

尖顶海山和平顶海山是洋底海山的两种类型,同时也是富钴结壳资源赖以成长的主要载体,两者在地形上具有显著差别,资源状况和分布也不尽一致。以地形分类为基础,就中太平洋海山区两类海山结壳的成矿特征、宏微观构造、矿物和化学组成以及空间分布等进行了比对研究。研究认为,尖顶海山体积虽小,但地形演化连续,底层流及环境氧化性较强,有利于结壳的长期稳定生长,结壳厚度总体较大,富成矿元素和生物组分,远景成矿区域连续绵长。平顶海山山体巨大,顶部和斜坡陡崖区不利于结壳成长,底流活动只在山顶边缘和山脊地带表现突出,环境氧化性整体较弱,后期构造活动相对频繁,结壳总体厚度较小,铁,碎屑和热液组分含量较高,远景矿区相对狭窄。     

富钴结壳矿区申请需要解决的两个重要问题

讨论了我国富钴结壳矿区申请需要解决的两个重要问题：①资源量评价方法;②结壳调查测站的位置和水深.认为在资源量评价中,应采用“平均含矿覆盖率”与“见矿率”综合使用的方法,同时必须对所有准备申请的拖网、海底摄像/海底照相有效测站的位置和水深进行校正,对我国准备申请的富钴结壳调查海山的资源量进行重新计算.     

富钴结壳分布的分形特征

利用我国在西太平洋国际海底两个海山获得的富钴结壳资料进行分形研究后发现，富钴结壳的分布具有变维分形分布的特点，结壳丰度呈二阶累计和分形分布，结壳厚度呈多阶不定累计和分形分布，通过计算得到了它们各自的分维数，进而对两个海山的结壳资源进行了初步评价。     

最近区域法与地质块段法在富钴结壳资源量评估中的综合应用

首次应用最近区域法对东太平洋某海山（简称X海山）进行了初步的资源量评估,最近区域法具有能对矿区无限分块和能快速圈定富矿区的优点,结合地质块段法的评估结果可以对矿区资源量进行综合分析。经过初步评估认为,该海山具有储量远景,应进行进一步的勘探研究。     

富钴结壳多维数据模型及矿区圈定研究

通过对各种矿区圈定数据的分析,运用地理信息系统(GIS)建立了地形、品位、厚度和矿区的多维数据模型,并根据国际海底管理局提出的矿区选取模型对某海山进行了矿区圈定,给出了一种矿区圈定结果,提出了矿区圈定优劣性评价参数并对结果进行了评价.研究结果表明,受数据量的限制,数据模型的效果不是非常理想,有必要结合地球物理数据进一步研究;在相同的勘探条件下,应用小块段模型比应用大块段模型可以获得更优的资源远景区;富钴结壳连续矿区中的斑状空白只有在面积大于一定值时才会对块段的放置和数量产生影响.     

富钴结壳资源评价和圈矿方法探讨

分析和讨论了我国现行富钴结壳资源评价所用的算术平均法在基础数据获取方面存在的问题,给出了相应的改进方案,并提出和引入了见矿率、成矿系数等新的评价参数,改进了现有方法的不足.围绕目前迫切需要解决的结壳圈矿工作中的界线问题,从调查方法、资料处理和界线确定等三方面进行了相应的理论探讨.这些工作将为当前我国富钴结壳申请矿区的选择、圈定以及资源评价提供技术支撑,也是后续矿区加密调查和钴结壳储量精细计算的重要依据.     

西太平洋Lamont海山中新世以来富钴结壳成矿环境的演化

分析了西太平洋Lamont海山12个站位33个富钴结壳样品的主元素和稀土元素,结果表明,该海山富钴结壳成因类型属于水成成因,并且在形成过程中基本未受到磷酸盐化作用的影响。Lamont海山的一个富钴结壳样品剖面的电子探针数据显示,该海山富钴结壳的成矿环境在新第三纪以来至少存在2个演化阶段:第1阶段,23~15 Ma,富钴结壳中Mn相对富集,成矿环境以富氧贫硅为特征;第2阶段,15~0 Ma,富钴结壳中Fe相对富集,成矿环境以贫氧富硅为特征。成矿环境的氧化能力总体上呈现下降的趋势。联系新生代世界大洋,尤其是西太平洋的地质演化背景,认为引起成矿环境演变的原因主要是西太平洋大洋板块的WNW向漂移和新第三纪以来全球水道开合,造成了Lamont海山所处海区最低含氧带逐渐减薄。     

Fine-scale compositional variations in a Co-rich Mn crust from the Marcus-Wake Seamount cluster in the western Pacific based on electron microprobe analysis (EMPA)

The internal structure and composition of a 37-mm-thick Co-rich Mn crust from the Lamont Guyot in the Marcus-Wake Seamount cluster have been studied in detail by means of electron-probe microanalysis (EPMA). 184 point analyses for 16 elements were carried out at an average spacing of 0.20 mm and each point was dated using the Co-geochronometer method. Two types of variation in composition were observed in the crust: long-term trends and short-term erratic variations. The long-term trends were identified using the fifth order polynomial. Mn and Ni were shown to increase in concentration from 23.3 Ma to a maximum at about 20 Ma and then decline steadily to the Present, whereas Fe, P and Si showed the opposite trend. By contrast, Co displayed a double humped pattern with maxima at about 19 Ma and 3.5 Ma and minima at 23.3 Ma, about 11 Ma and at Present. The long-term trends in element concentrations in the crust lead us to suggest that much of the Fe in western Pacific Ocean ferromanganese crusts is aeolian in origin and derived from the deserts of central Asia. Cooling of the Asian mainland at about 20 Ma led to an increase in the flux of Fe to the oceans. This was supplemented by an additional input of Fe into the crusts as a consequence of the dissolution of biogenic CaCO₃ tests at 4.5−10.5 Ma. For the short-term erratic variations, three periods of 0.61, 0.96 and 1.65 m.y. were identified by spectral analysis. The second harmonics of these periods are 1.22, 1.92 and 3.30 m.y., which may correspond to the highest-order periods for eccentricity of 1.31, 2.04 and 3.47 m.y. This suggests the possibility that the high-frequency oscillations of the time series data are linked to climatic changes controlled by the highest-order periods of the Milankovitch cycles.     

News from the seabed – Geological characteristics and resource potential of deep-sea mineral resources

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.     

基于连续沥取的富钴结壳成因机制的探讨

根据连续沥取实验结果及相关文献,富钴结壳的生长可用一个双阶段胶体-化学吸附模型来说明.第一阶段是混合胶体的形成及元素的清除与富集,富氧的底层水与缺氧、富Mn2＋的中层水体混合,Mn2＋被氧化而形成MnO2胶体,并与水柱中的Fe（OH）3、Al（OH）3、SiO2、Ti（OH）4等胶体形成多种混合胶体[MnO2-Fe（OH）3、Fe（OH）3-Ti（OH）4和Fe（OH）3-Al（OH）3-SiO2],后者根据各自的表面物理化学特征吸附和富集不同的元素;第二阶段是混合胶体的沉积及富钴结壳的生长,第一阶段形成的混合胶体在海山基岩上以氧化物或氢氧化物的形式沉积,吸附的元素结合进矿物点阵,然后通过自催化或自反馈的方式生长.在富钴结壳生长中,生物起着重要的作用,包括为富钴结壳的生长提供大量的成矿物质、对Mn2＋的催化氧化作用及在铁锰胶体的沉淀及富钴结壳壳层的生长过程中的媒介作用.     

中太平洋富钴结壳中生物标志物、有机碳同位素地球化学及其古海洋环境意义

利用2003年大洋DY105-12,14航次在中太平洋海山获取的KXD28富钴结壳样品,采用气相色谱(GC)内标法对该结壳样品的分层样进行了可溶有机质(氯仿沥青“A”)及其族组成(饱和烃、芳烃、非烃)、正构烷烃、类异戊二烯烃的定量分析,并结合总有机碳(TOC)及有机碳同位素(δ¹³C)分析,探讨了结壳样品有机质来源及富钴结壳组成与生长环境之间的关系。结果表明:(1)富钴结壳中有机质生物母源主要为海洋生物和菌藻类,并混有少量陆源物质;有机碳同位素同样也指示了海洋水生生物碳同位素特征;(2)KXD28结壳从底层到最外层有机碳同位素发生了很大变化,结壳中有机碳同位素组成变化与结壳生长过程中的海洋环境气候相符合:富钴结壳生长前期δ¹³C组成由正变负,对应全球气候变冷,南极底层流向太平洋挺进;而富钴结壳生长后期δ¹³C逐渐偏正,与全球气候变暖和南极底层流萎缩相关联。     

西太平洋Kocebu海山铁锰结壳稀土元素地球化学特征

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...     

Morphological Features of Co-Rich Manganese Deposits and Their Relation to Seabed Slopes

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.