During a research cruise of the New Zealand research vessel Tangaroa 1974 large manganese nodule fields with high density have been discovered in the Southwest Pacific. The chemical analysis was carried out on the dredges showing average grades of 16.7% Mn, 21.1% Fe, O, 22% Cu, o, 4o% Ni and O, 38% Co. The highest copper and nickel contents are at l% and therefore below the limit of 3%, which must be exceeded in general today, when the ore is to be regarded as an economically interesting . Comparisons of different analysis of manganese nodules size fractions showed that there are little differences in the chemical composition associated with nodule size. Also, the value of metal content in well-preserved nuclei volcanogenic nuclei is comparable with that of the nodule surface areas.

The samples were crushed to a fine powder and heated to 110°C.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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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.

Supplement to: Glasby, Geoffrey P; Bäcker, Harald; Meylan, Maurice A (1975): Metal contents of manganese nodules from the Southwestern Pacific Basin (Manuscript version). Erzmetall, 28(7-8), 340-342