Manganese crusts and nodules were retrieved from dredges and grabs performed during Cruise D16 of R.R.S. Discovery. Samples were analysed by a combination of atomic absorption spectrometry and direct-reading optical emission spectrography. Samples were first crushed in an agate mortarand pestle to pass 300 mesh and stored in sealed Polythene tubes. 'Salting' from previoussamples was minimised by washing the mortar and pestle with HC1, de-ionised water, andacetone, and, in order to minimise the effects of sampling errors, care was taken not toincorporate the nodule nucleus into the sample. Samples were ignited at 420°c for 4 h, cooled in a desiccator. The ignited material was then prepared for analysis. All analytical results except are presented on an air-dried basis.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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