The island of Oahu is made up of two almost parallel mountain ranges, the Koolau on the east and the Waianae on the west, with a sloping plateau of about 10 miles in width and 40 miles in length between these. This plateau comprises the principal portion of the arable land of Oahu. From the evidences at hand, the soil and deeper-lying disintegration products have resulted principally from the primary decomposition of normal basalt, under the influence of the usual weathering agencies incident to a humid subtropical climate. At intervals in this upland plain, there are areas which contain large quantities of manganese. Manganese concretions occur throughout the manganiferous soils of Oahu. Their chemical composition is similar to that of the manganese nodules found in the deep sea around the Hawaiian island during the Challenger expedition.

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1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions.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: Kelley, WP (1912): The function and distribution of manganese in plants and soils. Bulletin (Hawaii Agricultural Experiment Station), 26, 56 pp