Fig. 4: Distribution and cycling of carbon in the deep mantle during core formation (Early Earth) and in today’s Earth (Present Day Earth).
From: Tetracarbonates in silicate melts may be at the origin of a deep carbon reservoir in the deep Earth
Carbon becomes less siderophile with depth and as a consequence is stranded in the lowermost lower mantle as tetracoordinated carbon in silicate melts. With the solidification and convective motions, primordial carbon was accumulated in defined regions at the CMB32,33 known as LLVPs and ULVZs. The latter are believed to be the original source of hotspot volcanisms33,37, thus primordial carbon trapped at the CMB could be the primary source of carbon emissions in these locations (Hawaii, Samoa, Pitcairn and many others). Image credit: Josh Wood.
