Regional and depth variability in the composition of cobalt-rich ferromanganese crusts from the SOPAC area and adjacent parts of the central equatorial Pacific

Abstract

Three hundred and thirty-three Co-rich crust analyses, including new analyses from 56 locations, with data comprising Mn, Fe, Co, Ni and Cu concentrations and water depth, have been subjected to a one-way analysis of variance technique in order to assess factors controlling crust variability in the central Pacific. The two predominant influences on crust composition appear to be water depth and latitude. A model of crust composition variation related to the oxygen minimum zone appears to be applicable in the area studied. This model, however, does not explain the observed variations in the data with latitude. Variations in biological productivity about the equator, in addition to the oxygen minimum zone, can be held to account for the observed crust compositional variation with latitude.