During the campaign SO23/2 (R/V Sonne) in the South China sea various manganese deposits were retrieved by dredging. Two representative samples were selected for chemical analysis: one Mn crust (0.4 cm thick) attached to a vesicular olivine basalt fragment for station 40KD and one irregular spheroidal shaped Mn nodule with rough surface and a Miocene chalk core for station 44KD. In order to study the distribution of Th and U with distance, samples were drilled and the result was divided in equal parts. Liquid chromatography was used to separate and purify the Th isotopes. U and Th concentrations were determined using alpha spectrometry and 232Th isotope using atomic absorption spectroscopy.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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.This dataset represents the digitized Table 3 and 4, pp. 151 of the related publication.