The formation of cobalt-bearing ferromanganese crusts under fluid destruction of silicate matter

Resumo

The processes of fluid destruction of various silicate rocks under diffusion of flows of compressed gases (mainly carbonaceous) were studied. The gas condensate nature was ascertained for the forming alumoslilicate and ore (cobalt–iron–manganese hydroxide) substances produced under this fluid destruction in the forms of microcrusts and microconcretions. The ore condensates contained in high concentrations the typomorphic elements of oceanic ferromanganese formations (Mn, Co, Ni, Cu, Pb, Ce, and Pt). The elemental composition of the ore oxide substance formed under the destruction of various silicate matrices exhibits a definite degree of endemism with prevalence of the Co–Mn association. The pronounced concentration of barium is related to the substantially carbonaceous composition of the fluid systems. A cerium paradox is revealed: Ce³⁺ is oxidized into Ce⁴⁺ and absorbed by ferromanganese hydrogel and the minimum of cerium appears in rare-earth phosphates.