The area selected for the investigations of the VA-13/2 expedition of the Valdivia corresponds to area 2 of the previous VA-08 expedition performed in 1974. Its center coordinates are 9°25'N,146°00'W and it covers a square area of approximately 20 km. The aim of this expedition was to densify the previous 1974 network of observations and augment it by seismic data taken correlatively. This enabled a better mapping the facies zones of near-surface sediments. Furthermore, the dependence of manganese nodule chemistry upon topography on the one hand and the substrate on the other hand have been examined in more details.During the coarse of the R/V Valdivia VA-13/2 campaign, 597 multi-element geochemical analyses of manganese nodules and manganese crusts were carried out over 164 sampling. The analysis took place initially using a TRACOR-EDX device and after technical difficulties they were carried out using X-ray fluorescence. The samples were dried at 110°C for 24 hours and then ground to required analytical fineness.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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.