10Be, U and Th isotopes, Ra, 210Pb, Mn, Fe and several trace elements are measured in the hydroxylamine hydrochloride leachates and residues of two ferro-manganese nodules collected from the Central North Pacific. The two nodules which are from the same location are about identical in composition. The 10Be deduced growth rates (2.3 and 3.3 mm/10-6 years) are in good agreement with those reported in literature for other nodules using independent techniques. The order of magnitude discrepancy between the integrated SUP-10 Be activity (in the nodules) with its production rate confirms the earlier explanations put forward by Bhat et al (1970). Additionally it is possible that nodule formation results from only a few hundred meters of the overlying waters. Hydroxylamine hydrochloride appears to be an ideal leachant for the authigenic components in the nodules _ the leach can conveniently be used for most of the analyses.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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: Sharma, P; Somayajulu, Bammidipati L K (1979): Growth rates and composition of two ferromanganese nodules from the central North Pacific. in: Lalou, C. (Ed.), La Genèse Des Nodules de Manganèse. Centre National de la recherche Scientifique (CNRS), Gif-sur-Yvette, France, 281-288