The study reported here involved the analysis of 12 rare earth and 13 minor elements in 13 nodules from the S.W. Pacific; 1 nodule from equatorial N. Pacific (DOMES Site C) as well as 1 nodule and 2 crusts from the Hawaiian-Emperor chain. After collection the samples were oven dried, ground with a pestle and mortar, and passed through a 50 ?m nylon sieve. The samples were prepared for spark source mass spectrometric analysis by mixing them in a ratio of 1:1, with ultra pure graphite powder. Pure Lu203 was mixed with the graphite (final concentration 500 ppm). The chemical analysis was performed by Spark Source Mass Spectrometry. Selected isotope images on the photoplate were used to determine the Q-2 emulsion response curve. The mass spectrometric data are considered to have a precision of ± 15% (based on repeat analyses of the U.S.G.S. standard BCR-1).

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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