dc.contributor.author | Rajani, R.P. | |
dc.contributor.author | Banakar, V.K. | |
dc.contributor.author | Parthiban, G. | |
dc.contributor.author | Mudholkar, A.V. | |
dc.contributor.author | Chodankar, A.R. | |
dc.date.accessioned | 2006-07-13T12:10:09Z | |
dc.date.available | 2006-07-13T12:10:09Z | |
dc.date.issued | 2005 | |
dc.identifier.citation | Journal of Earth System Science, vol.114(1), 51-61pp. | |
dc.identifier.uri | http://drs.nio.org/drs/handle/2264/210 | |
dc.description.abstract | Eight ferromanganese crusts (Fe-Mn crusts) with igneous and sedimentary substrates collected at different water depths from the Afanasiy-Nikitin Seamount are studied for their bulk major, minor and rare earth element composition. The Mn/Fe ratios < 1:5 indicate the hydrogenetic accretion of the Fe-Mn hydroxides. These Fe-Mn crusts are enriched in Co (up to 0.9%, average approx. 0:5%) and Ce. The Ce-content is the highest reported so far (up to 3763 ppm, average approx. 2250 ppm) for global ocean seamount Fe-Mn crusts. In spite of general similarity in the range of major, minor, and strictly trivalent rare earth element composition, the dissimilarity between the present Fe-Mn crusts and the Pacific seamount Fe-Mn crusts in Co and Ce associations with major mineral phases indicates inter-oceanic heterogeneity and region-specific conditions responsible for their enrichment. The decrease in Ce-anomaly (from approx. 8 to approx. 1:5) with increasing water depth (from approx. 1:7 km to approx. 3:2 km) might suggest that the modern intermediate depth low oxygen layer was shifted and sustained at a deeper depth for a long period in the past. | |
dc.format.extent | 264192 bytes | |
dc.format.mimetype | application/pdf | |
dc.language.iso | en | |
dc.publisher | Indian Academy of Sciences | |
dc.title | Compositional variation and genesis of ferromanganese crusts of the Afanasiy-Nikitin Seamount, Equatorial Indian Ocean | |
dc.type | Journal Article | |