Surface sediments were collected during the GH79-1 cruise, Geological Survey of Japan, from the area of 10°-13°N and 165°-180°W. Material for this study (34 samples) was selected from box core samples. The samples examined were mainly of an argillaceous or calcareous-argillaceous type. They were dried at 110°C, ground, and subsequently split into fractions. One fraction was analysed with automatic X-ray fluorescence spectrometer JOEL-IOOS for Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K, and P. Other fractions were analysed for total water, ignition loss, dissolved chlorine, ferrous iron, and carbonate.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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 XVI-1, pp. 231 of the related publication.---Residual materials were calculated by subtracting CO2 and H2O from ignition loss. They may contain sulfur, organic materials and other