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| Main Authors: | , |
|---|---|
| Format: | Dataset Open Access |
| Language: | en |
| Published: |
PANGAEA
1995
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| Subjects: | |
| Online Access: | https://doi.org/10.1594/PANGAEA.860777 |
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Table of Contents:
- 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.