Preliminary results of chemical analysis of thirteen ferro-manganese nodules dredged from the Mariana and Ogasawara regions via the KH-84-1 cruise are presented. Five Mn nodule samples from the stations of 16, 19, 23 and 25 in and around the Mariana Trough and seven Mn nodules at stations 2, 3, 5, 8 and 27 in the Ogasawara Plateau were selected for chemical analyses. Ferromanganese oxide crusts were separated from Mn nodules and were soaked into the distilled water for two days. After drying at 110°C for 12 hours, they were powdered in an agate mortar. About 500 mgr of each sample was dissolved in the mixture of dilute nitric acid and dilute hydrogen peroxide. After removing silicate residue by filtering, the solution was proceeded for induced coupled plasma (ICP) analysis at Tsukuba University. Abundances of rare earth elements (REE) and several trace elements were also determined by instrumental neutron activation analysis (INAA).

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 Tables 7-12-1 and 7-12-2, pp. 242-243 of the related publication.