11:30 AM - 11:45 AM
[SIT06-10] Lattice thermal conductivity of lower mantle minerals
Keywords:lower mantle , thermal conductivity, bridgmanite, ferropericlase
We measured the lattice component of thermal conductivities both of (Mg,Fe)(Si,Al)O3 bridgmanite and (Mg,Fe)O ferropericlase at the Earth’s lower mantle pressures and 300 K using a pulsed light heating thermoreflectance technique in a diamond anvil cell. We found that iron incorporation into bridgmanite shows minor effect on the thermal conductivity. On the other hand, the obtained conductivity of ferropericlase was considerably lower than that of MgO periclase. The estimated lattice thermal conductivity of bridgmanite-dominant lowermost mantle is comparable to conventionally assumed value of 10 W/m/K (Stacey, 1992). However, our results imply that local existence of (Mg,Fe)O ferropericlase in the lower mantle induce strong heterogeneity of thermal conductivity.
Lay, T. et al.: Nature Geosci. 1, 25-32 (2008).
Stacey, F.: Physics of the Earth, 3rd ed. (1992).