The objectives of RRS Discovery Cruise 156 was to provide a qualitative and quantitative description of the midwater and benthic ecosystems at a site on the Madeira Abyssal Plain (Great Meteor East). During this expedition a trawl and a photographic sledge with dredging capabilities observed and gathered a large number of manganese nodules.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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