The authors have selected manganese nodules broadly representative of world oceanic areas. Approximately 1 gram of each manganese nodules was leached with 25-mi 6N HC1. Lead was extracted from the supernate by conventional anion exchange techniques, followed by a single dithizone extraction. Lead-isotope ratios were determined by mass spectrometry.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 1, pp. 5125 of the related publication.