Oceanic manganese nodules samples were obtained from the Scripps Institution of Oceanography. They were subsamples of the powdered material used for studies of the major and minor element geochemistry of the deposits by Clavert and Price, 1977 (see Related to: reference). The powdered samples were leached with 0.1 M HCl at a ratio of 1:4 by weight at room temperature for 140 days after which the leachate and the residue were separately analyzed. The determinations of Fe, Mn, (atomic absorption spectrophotometry) and P (colorimetry) were made on the leachate. The REE were analysed by mixed-solvent ion exchange and mass spectrometric isotope dilution. Isotope analyses were performed on an A.E.I. MS5 mass spectrometer. RMS precision were generally 2% (and often 1%). except for La (5%). Eight replicate analyses of USGS standard rock BCR-1 wre used for comparison.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 Table2 - Part 1, pp. 516 of the related publication.