The nodules examined were sampled during the R/V Valdivia cruises VA 04, 05, 09, 13/1, and 18. The majority of these samples was taken from a region extending from 135°w to 155°W and from 5° N to 15°N. In the pelagic area investigated a very fine-grained siliceous ooze to siliceous clay is dominant. Three genetic types have been determined: type A (diagenetic) mainly on slopes or in the vicinity of seamounts; type B (Hydrogenetic) in the center of the basin regions and type C (dia-hydrogenetic) characterized by a vertical dual structure with a smooth top and and a rough gritty bottom separated by a distintive knotted botryoidal equatorial band. Chemical analyses have been performed on dried samples.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 1, pp. 63, of the related publication.