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

Resumo

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.