Selected manganese nodules both from deep-sea environments of the Pacific Ocean and epicontinental near-shore areas (Canada west coast and Baltic Sea) have been studied to investigate the incorporation of minor transition metals in liaison with their mineralogy. The samples were pulverized, sieved through a pre-washed 150 mesh nylon net and subjected to chemical analyses. A 0.1-0.5g aliquot of powdered nodules was dissolved in 20 ml of 6 N HCl and subjected to chemical analysis by atomic absorption spectrophotometry.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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