A suite of ferromanganese oxide crust specimens was collected by R.R.S. Shackleton in 1975 as part of the continuing study at Imperial College of North West Indian Ocean nodules and encrustations. The samples analysed were drilled out at points of varying depth within the specimens using a hand drill with a 2 mm stainless steel bit. The samples were then ground up and dried in a desiccator. They were subjected to a standard HF/HNO3/HClO4 attack, and taken into solution for analysis by atomic absorption spectrophotometry for Fe, M n, Co, Pb, Cu, Zn, Al, Ti, Mg, Ca, Cd and Li. Analytical precisions were generally better than 10 96, and usually better than 5 %. However, Cd and Li had precisions generally worse than 15 % , because their concentrations were nearer the detection limit of the method.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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.--Please note, that the paper does not contain the datatable, which was directly transmitted by the authors to NOAA-NGDC.