Energy dispersive X-Ray analysis (EDAX)has been performed on micro-samples extracted from various surface and inside layers of manganese nodules and manganese crusts covering basalt or volcanic breccia rocks. Measurements have been performed on pellets built from the samples reduced to powder. Results are presented as average of about 10 point measurements. Concentrations have been normalized at 100% of total metal oxides.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 Annex7-A, pages 201-205 of the related publication.