The nodules used in this study were collected from two cruises in the western North Pacific by box coring (KH-79-4) and dredging (GH-78-1). After being dried at 110°C each sample extracted from the top, side and bottom of the nodule at various penetration levels, a chemical separation technique was used in a 6% acetic acid solution (fraction A). The residual was then submitted to a mixture 6% (IM) acetic acid and IM hydroxylamine hydrochloride (a reducing agent). The leachant is designated as fraction B and the dry residual (fraction B). On each part, acetylene-air flame atomic absorption spectrophotometry was used for the determination of Fe, Mn, Co and Ni. Aluminium was determined by acetylene-nitrous oxide flame atomic absorption spectrophotometry. Flameless atomic absorption spectrophotometry was used to determine Co, Ni and Cu. Dissolved silicate was determined by the standard colorimetric method of molybdenum yellow by adding boric acid as a masking agent for fluoride. The table presents the bulk composition as a recombination of the 3 parts analysed.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 Table 1 (pp. 202) of the related publication.