Annotated record of the detailed examination of Mn deposits from R/V Xiang Yang Hong 16 stations (1983) in the Pacific Ocean

Electron microprobe and X-ray diffraction data for north Pacific manganese nodules reveal that the transition metal distributions are controlled by the mineralogy. Microlayers rich in 10Å-manganates generally have high Mn/Fe ratios and positive correlations between Ni, Cu and Mn, and between Co and Fe. Microlayers rich in vernadite, on the other hand, show low Mn/Fe ratios, and Co, Ni and Cu all show positive correlations with Mn. The 10Å-manganates form mainly in porewaters with high Mn/Fe ratios. The Ni2+ and Cu2+ ions are post-depositionally incorporated into the interlayers of the manganates, whereas Co3+ is substituted for Fe3+ in ferric oxyhydroxides. In seawater with a low Mn/Fe ratio, on the other hand, the adsorption of positively charged ferric oxyhydroxides on negatively charged [MnO6] octahedral layers suppresses the growth of 10Å-manganates, enhancing the formation of vernadite. Positively charged hydroxides of Co3+, Ni2+ and Cu2+ are also adsorbed on the [MnO6] layers. These mechanisms of mineral formation and metal uptake are corroborated by data for other oceanic non-hydrothermal manganese nodules and crusts.针对北太平洋锰结核开展的电子探针（Electron microprobe）与X射线衍射（X-ray diffraction）分析数据表明，过渡金属的分布特征受控于矿物学组成。富含10埃锰酸盐（10Å-manganates）的微层普遍具有较高的锰铁比，且镍（Ni）、铜（Cu）与锰之间，以及钴（Co）与铁之间均呈现显著正相关。反之，富含水羟锰矿（vernadite）的微层则表现出较低的锰铁比，且钴、镍、铜均与锰呈正相关关系。10埃锰酸盐主要形成于锰铁比较高的孔隙水环境中。二价镍离子（Ni²+）与二价铜离子（Cu²+）经沉积后被掺入锰酸盐的层间结构内，而三价钴离子（Co³+）则通过同晶替代进入羟基氧化铁中的三价铁离子（Fe³+）位点。在锰铁比较低的海水中，带正电荷的羟基氧化铁会吸附于带负电荷的[MnO6]八面体层表面，抑制10埃锰酸盐的生长，同时促进水羟锰矿的形成。三价钴、二价镍与二价铜的带正电氢氧化物同样会吸附于[MnO6]八面体层上。上述矿物形成与金属摄取的相关机制，得到了其他海洋非热液锰结核及结壳的分析数据的佐证。