Ferromanganese deposits from the North Pacific and Blake Plateau have been sampled from potential mining sites either by the industry (Deepsea Ventures, Kennecott Corporation, Hughes) or by the Univeristy of Hawaii. The bulk composition of the different manganese nodules and crusts constituents was detrmined using Atomic absorption spectrometry analysis performed after acid leaching.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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