The authors have analysed the chemical composition of "zero-age" samples from the Mid-Atlantic Ridge and compared them with similar results obtained for the East Pacific Ridge area.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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

Supplement to: Melson, William G; O'Hearn, Timothy (1986): "Zero-age" variations in the composition of abyssal volcanic rocks along the axial zone of the Mid-Atlantic Ridge. in: Peter R. Vogt & Brian E. Tucholke (eds) The geology of North America, the western North Atlantic region; http://geoscienceworld.org/georef/1987-023650, 117-136