Inside core 710KH, manganese micronodules are much more abundant in the coarse fraction (> 40 μm) of the dark brown clay horizon than in the upper sedimentary unit and are characterized by higher ratios and higher Ni and Cu contents than those from the upper-sediment horizon. This reflects the fact that these "overconsolidated" sediments are well oxidized and that element remobilization from the micronodules has not taken place within this sediment type. In the upper sedimentary unit there is a sharp drop in the ratio and Ni and Cu contents of the micronodules immediately beneath the sediment surface, reflecting the selective migration of Mn and other transition elements such as Ni and Cu from the micronodules.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 II (pp. 232-233) of the related publication.