Manganese nodules from VA13/2 cruise (R/V Valdivia) were selected for a variety of morphologies and size. They were regrouped by size class and chemically analyzed in bulk. Mn, Fe, Ni, and Cu concentrations were determined by X-ray fluorescence spectroscopy following grinding and drying of the samples at 1l0°C for 24 hr. The elements Co, Zn, Al, Si, and Ba were analyzed in selected samples by atomic absorption spectrophotometry in Aachen. In addition, the percent lithogenous fraction of selected samples was determined following treatment of the sample by 25 percent HCl. Element composition in these nodules was then computed on a lithogenous-free basis to make allowance for the effects of variation in the silicate contents of the nodules.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 11, pp. 255, of the related publication.