Effects of iron on the lattice thermal conductivity of Earth's deep mantle and implications for mantle dynamics.

ABSTRACT: Iron may critically influence the physical properties and thermochemical structures of Earth's lower mantle. Its effects on thermal conductivity, with possible consequences on heat transfer and mantle dynamics, however, remain largely unknown. We measured the lattice thermal conductivity of lower-mantle ferropericlase to 120 GPa using the ultrafast optical pump-probe technique in a diamond anvil cell. The thermal conductivity of ferropericlase with 56% iron significantly drops by a factor of 1.8 across the spin transition around 53 GPa, while that with 8-10% iron increases monotonically with pressure, causing an enhanced iron substitution effect in the low-spin state. Combined with bridgmanite data, modeling of our results provides a self-consistent radial profile of lower-mantle thermal c

SUBMITTER: Hsieh WP 

PROVIDER: S-EPMC5910838 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature