Behavior of Zn<Superscript>2+</Superscript>, Cd<Superscript>2+</Superscript>, Ba<Superscript>2+</Superscript> and Pb<Superscript>2+</Superscript> cations in ferromanganese crusts from the Marcus Wake seamount (Pacific Ocean) in aqueous solutions of metal salts

The behavior of heavy-metal cations in ore minerals of cobalt-rich ferromanganese crusts from the Marcus Wake seamount in aqueous solutions of metal salts was studied in experiments. The Zn²⁺ and Cd²⁺ cations showed high reactivity and Ва²⁺ and Pb²⁺ showed low reactivity. It was found that Zn²⁺ and Cd²⁺ cations within the ore mineral composition are mainly absorbed (up to 66%) whereas Pb²⁺ and Ва²⁺ are chemically bound (up to 70%). Ore minerals in the crusts are characterized by sorption properties and high ionexchange capacity by these cations (1.94–2.62 mg-equiv/g). The capacity values by heavy-metal cations for ore minerals of the crusts from different areas of the Marcus Wake seamount are close to each other.     

Mineralogy and Geochemistry of Co-bearing manganese crusts from the Govorov and Volcanologist guyots of the Magellan Seamounts (Pacific Ocean)

Co-bearing manganese crusts (CMCs) from the Govorov and Volcanologist guyots (Magellan Seamounts, Pacific Ocean) are of the same type and consist of three layers (I-1, II, III) and a “dried crust” variety of layer III. It is shown that the structural and textural pattern are quite similar within individual layers. The major ore minerals of the crusts are poorly crystallized, have a low degree of structural ordering, and include Fe-vernadite, Mn-feroxyhyte, and less abundant, well-crystallized, and structurally ordered vernadite. It is shown that the cations of ore (Со, Ni, Cu), rare, and rare-earth metals are irregularly concentrated in ore minerals of CMCs, which provides evidence for the pulsating nature of their supply at different geological stages.