Manganese nodules dredged in the Indian Ocean by R/V Marion Dufresne have been selected in conjunction with cores taken in their vicinity. Most of these samples are spherical or botryoidal with a volcanics core. The rind around the cores were separated and dryied at 100°C during 48 hours before being crushed into a fine powder. Rare earth elements (REE) composition was determined by neutron activation analysis.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 3, p. 263 of the related publication.