The environmental conditions and processes that result in the origin and growth of marine manganese nodules have been of interest to both science and industry for more than 100 years, yet they are still poorly understood. The best way to investigate the significant internal features of whole nodules is to study their polished cross sections by the methods of ore microscopy. In this report, basic principles of ore microscopy are reviewed and methods of making good sections from difficult materials are described. The use of "map" photographs and mineral identification by X-ray analysis of microsamples are recommended.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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: Sorem, Ronald K (1989): Manganese nodules as ore - Research methods and applications. Marine Mining, 8(2), 185-200