The usefulness of cosmogenic beryllium-10 (half life = 2.5 Ma) for studying the rates of accumulation of ferromanganese nodules is reported based on its measured depth distribution in the top 20 mm of these deposits. Accumulation rates have been obtained in the range of 1 to 4 mm/Ma, which are in good agreement with rates determined using the 230Th method on the same nodules. The use of 10Be offers promise in extending the dating to the outer few cm of the nodules. This contrasts with conventional methods using 230Th and 231Pa isotopes which, due to their comparatively short half lives, are limited to a few mm at the surface of the nodules. Detailed studies of 10Be in the manganese deposits coupled with other trace element analyses should prove valuable in understanding the processes of formation of these deposits and the chronology of events recorded by them.

9Be concentrations are relative to dry sample weight and are taken from: Bhat, S. G., Krishnaswamy, S., Lai, D., Rama, and Somayajulu, B. L. K., 1970, Radiometric and trace elemental studies of ferromanganese nodules: Proceedings of the Internal. Symposium on Hydrogeochemistry and Biogeochemistry, Tokyo, Sept. 1970.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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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: Krishnaswami, Seth; Somayajulu, Bammidipati L K; Moore, Willard S (1972): Dating of manganese nodules using beryllium-10. in: D. R. Horn (Ed.), Ferromanganese deposits on the ocean floor, National Science Foundation, Washington, 117-122