Manganese crust samples were dredged from the Line Islands Ridge and the MidPacific Mountains that were recently taken during the R/V Sonne SO18 (Midpac 81) cruise. The metal composition of the outermost millimetre of the crusts where growth rates were determined is given in Table 1. The concentrations were measured on dried substance. Mn, Fe were determined by potentiometric and complexometric titration methods; Ni, Cu, Co were analysed using differential pulse polarography. All analytical data are results of repeated determinations having <1% of relative error for main constituents (Mn, Fe), and <5% of relative error for minor constituents (Ni, Co, Cu).

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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. 718 of the related publication.