Cobalt-Rich Ferromanganese Crusts of the Govorov Guyot of the Magellan Seamounts of the Pacific Ocean: Conditions of Occurrence, Mineralogy, and Geochemistry

Abstract—The article describes the geological conditions of the formation of cobalt-rich ferromanganese crusts on the Govorov guyot in the Magellan Seamount system of the Pacific Ocean. It is established that the crusts are deposited on dense organogenic-clastic limestones, breccias, and volcanoclastic rocks. Crusts are three-or four-layer formations. The main ore minerals of all layers of crusts are Fe-vernadite, vernadite and Mn-feroxyhyte. It has been found that the Fe content increases and Mn content decreases from layer I-1 to layer III. For the ore cations of metals—Co²⁺, Ni²⁺, Cu²⁺—no regularity in their distribution has been established: in some crusts, their content decreases from layer I-1 to layer III, while in others, it increases. The most stable content of heavy metal cations in the guyot crusts is Zn²⁺, Mo⁶⁺, Sr²⁺, Cd²⁺, Ba²⁺, and Pb²⁺. The distribution of rare-earth metal cations in the layers of different crusts is not the same and does not coincide with the distribution of Fe(III). And only for Ce³⁺ is its distribution is close to that of another ore—forming element of crusts—Mn(IV). It was found that the increased and maximum (1.08 g/t) Pt content is observed in layer II, the minimum in layer III of crusts.