Quantitative and qualitative chemical analyses were performed on fourteen manganese nodules and crusts from the Waho Shelf. The analyses showed that submarine weathering has leached several elements, notably Si02, A1203, Na20, CaO and MnO from the hydrated glass surrounding the basaltic seeds of the nodules. The altered glass was enriched in Ti02, MgO, K2O and total Fe. The manganese bands formed on the altered glass were further depleted in Si02, Al203, and similar to the hydrated glass in Na2O and CaO content. The manganese-enriched zones also showed higher TiO2 and NiO than the basaltic seeds, and higher total Fe than pelagic nodules from the North Pacific. Qualitative measurement of Cu, Ni, and Co, showed relative enrichment in the manganese bands. A proposed model for manganese accretion in the Waho Shelf incorporates local submarine weathering of basalts, redistribution of Mn in marine sediments, and an influx of Mn "rain" on the sea floor.
Allowance for H2O was made by deduction from other chemical elements assay.From 1983 until 1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions. At the time it was the most extended data compilation on ferromanganese deposits world wide. Initially published in a proprietary format incompatible with present day standards it was jointly decided by AWI and NOAA to transcribe this legacy data into PANGAEA. This transfer is augmented by a careful checking of the original sources when available and the encoding of ancillary information (sample description, method of analysis..) not present in the NOAA-MMS database.
Supplement to: Fein, Charles D; Morgenstein, Maury (1973): Microprobe analysis of manganese crusts from the Hawaiian Archipelago. In: Phase I Report - Inter-University Program of Research on Ferromanganese Deposits of the Ocean Floor. Seabed Assessment Program, IDOE, NSF, Washington D.C., USA - http://catalog.hathitrust.org/Record/005761114 (pdf 733 kB), 85-92
