Surface manganese nodules were sampled from the surface of a box core which was retrieved during tha VA-13/1 expedition of the R/V Valdivia in the Pacific Ocean. Most of these nodules from a siliceous radiolarian ooze covered abyssal plain were discoidal in shape with a botryoidal surface. In order to evaluate their internal chemical composition variability they were sectionned tranversaly and submitted to Atomic Absorption Spectrophotometry 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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 Appendix of the related publication.