Central Pacific Cobalt-Rich Ferromanganese Crusts: Historical Perspective and Regional Variability

摘要: Interelement correlations coupled with X-ray mineralogy, chemical analyses, and Q-mode factor analysis define five phases that compose ferromanganese crusts: δ-MnO2, Fe-phases including Fe oxyhydroxide silicate, detrital aluminosilicate, biogenic phosphate, biogenic-nonphosphate. This last phase is derived primarily from the dissolution of carbonate silica. These are characterized by following elements respectively: Co, Mn, Ni, Pb; Fe, Si, As; Al, Cr, Ti, K; P, Ca; Cu, Ba, Zn, Cd. The distribution δ-MnO2 related to latitude controlled equatorial zone higher productivity, which produces a strong extensive oxygen-minimum zone. iron similarly distributed, but overall variability not as great for phase. has inverse greatest at latitudes, especially in areas beneath trade-wind belt. composed eolian debris volcanogenic eroded submarine outcrops bottom currents. phosphate clearly distributed latitude, longitude, or high biological productivity. biogenic-nonphosphate most prominent