The composition of the acid-insoluble residue and hydrolysate fraction has been determined for manganese crusts and coatings retrieved along an equatorial Pacific transect surveyed during campaigns COPANO of R/V Le Suroit and SO-06 of R/V Sonne as part of the I.C.I.M.E. (International Cooperative Investigations of Manganese Nodule Environments) Project. In order to determine the percentage of acid-insoluble residue and the composition of the hydrolysate fraction in the manganes nodules, a bulk chemical analysis of the was first carried out. The samples were dried for 48 hours at 105°C. 0.5 g of each sample was then treated with 10 mls of HF/HNO3/HCl in a 5/2/3 mixture in a water bath for one hour at 80°C. 50 mls of saturated boric acid were added in the solution heated again for one hour in the water bath. The solution was then made up to 100 ml with distilled water and the resultant solution analyzed 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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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.This dataset represents the digitized Appendix-B (pp. 214-217) of the related publication.