Influence of seamount topography on the local facies variation in ferromanganese deposits in the Indian Ocean
1988; Pergamon Press; Volume: 35; Issue: 8 Linguagem: Inglês
10.1016/0198-0149(88)90094-5
ISSN1878-2477
AutoresRanadhir Mukhopadhyay, Bejugam Nagendernath,
Tópico(s)Marine Biology and Ecology Research
ResumoThe morphology and chemistry of ferromanganese nodules and encrustations from a seamount in the Central Indian Ocean Basin show local variations. Nodules from the summit of the seamount have sporadic distribution, are less spherical, have smooth surfaces, have lowest oxide/nucleus (O/N) ratios, and contain low values of Mn/Fe, Ni and Cu. In contrast, nodules from plains at the base of the seamount show greater abundance, are more spherical, have rougher surfaces, register high O/N ratios, and highest Mn/Fe, Ni and Cu. An increase in element concentration (Mn/Fe, Ni%, Cu%) and roughness of nodule surface is directly proportional to the increased thickness of the “acoustically transparent layer”. Morphochemical characters of these nodules suggest hydrogenetic and diagenetic formation in the summit and plain areas, respectively.
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