2 nodules, one spherical, similar to 2 cm diameter form L. Alstern, Sweden the other saucer-shaped, similar to 2 cm thick from L. Oneida, New York were studied by using 228Ra and super(210)pb in order to measure accretion rates in the range 100-1000 mm/10 super(3) year. The deduced rates are 1.4 and 2.6 mm/ 10 super(3) year. Respectively. The author discuss the problems of how deep sea noducles stay at the sediment-water interface when the sediment around them is accumulating 1000 times faster than the nodules themselves.

The analysis was conducted in the HCL soluble fraction.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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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; Moore, Willard S (1973): Accretion Rates of Freshwater Manganese Deposits. Nature Physical Science, 243(129), 114-116