中太平洋多金属结壳的地球化学特征

采用XRF和ICP AES法对中太平洋CA等6座海山的4 0多个站位的多金属结壳中化学元素进行测试与分析, 并结合其他资料对调查区结壳主要成矿元素的含量组成、特征变化、元素间的相关关系以及结壳与水深、地形等重要环境因子进行探讨.研究表明太平洋海山结壳中元素丰度特征具有多种变化类型, 中太平洋结壳主成分和成矿元素丰度明显高于马绍尔群岛, 而与西北太平洋、麦哲伦海山相近; 中太平洋结壳化学元素相关关系分析表明: Ca与P、Al与K呈显著正相关性; Mn与Al呈显著负相关性.研究还发现中太平洋结壳富Co(0.6 3%)而贫Cu(0.1 1 %)及高Fe(1 6.9%)低Mn(2 1.3%)的分布特征, 与深海多金属结核在含量分布特征上存在较大差异.与多金属结核相比: 结壳中Mn组元素含量显著降低, Fe组元素含量和稀土总量明显增大, 尤其是Co和REEs的变化最为突出。 

Geochemical Features of Multi-Metallic Crust in the Middle Pacific Ocean

Multi-metallic crust from seamount is one kind of oceanic mineral resources with the most perspective exploitation. More than forty samples of the multi-metallic crust from six seamounts in the middle Pacific Ocean were analyzed by X-ray fluorescence and ICP-AES. Combining with the published data, the constituent variety and the elemental relationships are discussed under the consideration of the depth and topography of the crust derivation. The results show that the contents of the main ore-forming constituents in the samples from the middle Pacific Ocean are similar to those from the northwest Pacific Ocean and from Magellan, and that are slightly higher than those from Marshall. Obviously positive correlations between Ca and P, as well as Al and K, but negative correlation between Mn and Al, are found in the samples from the middle Pacific Ocean. Higher Co (0.63%), Fe (16.9%) and REEs, but lower Cu (0.11%) and Mn (21.3%) are also found in the middle Pacific Ocean than in the deep-sea multi-metallic nodules. The facts imply that the ore-forming environment of the crust and the nodule was different.