Publication Date:
2023-08-28
Description:
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.
Keywords:
Comment; Deposit type; DEPTH, sediment/rock; Dredge; DRG; Event label; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; Pacific Ocean; Position; Quantity of deposit; Sediment type; Visual description; Xiang Yang Hong; XYH16-83; XYH16-83-M10; XYH16-83-M12; XYH16-83-M15; XYH16-83-M20; XYH16-83-M6
Type:
Dataset
Format:
text/tab-separated-values, 25 data points
