The chemical composition of marine ferromanganese nodules and crusts

Abstract

Crusts on seamounts are usually of hydrogenous origin and have high contents of Co and low contents of Cu. Nodules almost buried in pelagic siliceous oozes are commonly of oxic diagenetic origin and have high contents of Ni and Cu. Their mineralogy is todorokite. Suboxic diagenetic nodules in hemipelagic environments have low contents of cationic transition elements, especially of Co. Hydrothermal crusts of which mineralogy is todorokite or birnessite have extremely low contents of cationic transition elements, which are mainly due to the rapid growth of hydrothermal crusts. The chemical composition of deep-sea sediments can be simulated by admixtures of aluminosilicates with the average shale composition and Fe-Mn oxides with manganese nodule compositions of four different origins. -from English summary