All the samples were air-dried, crushed, and ground to a fine particle size (<100 mesh). Flame analyses were carried out with a solution that was obtained by the digestion of a 0.5-g sample of nodules in a Teflon-lined vessel. The resulting solution was transferred to a 100-mL volumetric flask containing 70 mL of a 5% boric acid solution and diluted to the mark. Standard solutions of the elements were prepared in an identical manner with 5% boric acid solution. Atomic absorption and emission spectrophotometric analyses were carried out for 22 elements with a Varian Model 5 atomic absorption spectrophotometer. A nitrous oxide-acetylene flame was used for the determination of Al, Ba, Mo, Sr, V, Ti, and Si. Arsenic was determined with a tantalum boat and a hydrogen-nitrogen flame, and the remaining elements were determined with an ai-acetylene flame.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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.--This tables is digitized from Table IV - B, pp. 2200 of the linked publication.The data presented result from an average over 5 replicate analyses