Silicon, aluminum, calcium, titanium and iron percentages were obtained by X-ray fluorescence analysis using an EDAX International EXAM system. Sediment samples collected during the Tangaroa cruises have been analyzed for the concentrations of nine elements. Sediments were dried at 80°C for about 48 hours, and ground to a fine powder. After mixing 1:1 by weight with boric acid powder, each sample was pressed into an aluminum "spec" cap at about 10,000 psi pressure. Manganese, nickel, copper and cobalt contents were determined by atomic absorption spectrophotometry. Prior to this analysis powdered samples were dried at 110°C to constant weight, and placed in a desiccator to cool. Approximately 0.2-0.3 g of each was weighed into a Teflon beaker, and acidified with 5-15 ml aqua regia (2:1 hydrochloric acid:nitric acid). Samples were heated to a boil and evaporated to near dryness (2-3 hours). About 10-15 ml hydrofluoric acid and 0.5 ml perchloric acid were then added to insure total dissolution. Sample absorbance values were measured with a Perkin-Elmer Model 603 Atomic Absorption Spectrophotometer.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 dataset represents the digitized version of Appendix H - pp. 286 of the related publication.