Fifty-seven samples of manganese nodules from the GH78-1 area were analysed in bulk rock for major and some minor metal elements to provide the data for the evaluation of the chemical features of the nodules. Air-dried sample of 0.1 g was decomposed with a mixture of 5 ml of hydrochloric acid and 5 ml of nitric acid in a covered 50 ml beaker on a boiling bath for about 30 minutes. After cooling, the solution was filtered into a 100 ml calibrated flask and diluted to the mark with water. The analyses for Mn, Fe, Co, Ni, Cu, Zn and Pb were done by atomic absorption spectrometry. The total water was analyzed gravimetrically.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 Table XIV-1, pp. 227-228 of the related publication.