(Table 3, Page 147), Chemical analysis of Mn deposits recovered South of New Zealand during R/V Eltanin Cruise 36 (NZOI Collection)@en

The samples were digested in a mixture of HNO3/HCl/HFf evaporated to dryness, fumed with HClO4 and finally leached with 8N HCl.
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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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.