| Seismological and geochemical observations have revealed a complex structure for the earth's core-mantle boundary (CMB) region, with lateral and chemical heterogeneities. The presence of higher than expected concentrations of siderophile elements (Ni, Co, Pt etc) in the earth's mantle, iron enrichment of the lower mantle relative to the upper mantle, and a possible carbon flux from the core suggest the possibility of continual long-term exchange of materials between the core and the mantle. The chemical interactions of molten iron with complex mantle oxides and diffusion have been postulated as key mechanisms. A number of studies have been carried out on the reduction reactions taking into account the extreme conditions of... |
