The Middle America Trench was first drilled in 1979 during Leg 66 off Oaxaca, Mexico and Leg 67 off Guatemala as part of a broad effort to study the mechanics of plate subduction and continental accretion and erosion. Leg 84 was recommended by the JOIDES Advisory Panels specifically to further examine the tectonic and gas-hydrate problems which had been revealed in the previous survey.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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