The Midpac '81 (SO18) exploration voyage with the R/V Sonne was a first step to study the regional distribution, nature and formation of Co-rich manganese crusts over submarine mountains. The expedition involved scientists from Preußag AG, the BGR Hanover, the University of Hamburg, the GKSS, the IfM Bremerhaven, the University of Bremen, the Technical University Clausthal and a USGS Woods Hole team led by F. T. Manheim. Part of the recovered samples were analysed for their main and trace chemical composition in the BGR Hanover using Atomic absorption spectrophotometry (AAS).

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 a part of the digitized Table 4, pp. C04-1 to C04-7 of the related publication.