The structure of the principal manganese minerals of the nodules, todorokite and birnes- site, is determined by the structure of hydrated manganese dioxide. Using this fact and the results of solution of the nodules in acids it is demonstrated that Ni, Cu, Co, and Zn are adsorbed on the hydrated manganese and iron oxides. The correlation coefficients for the elements in the nodules from the deep-water basins of the Pacific Ocean and from the region of the Mid-Pacific Mountains are computed, and it is shown that the correlation between Co and Mn and Fe changes in character with depth. The contents of Ni and Cu are correlated with Mn/Fe ratio.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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.