Thermal conductivity of carbonate and hydrous minerals in Earth's deep interior
Abstract
Knowledge to the thermal conductivity of deep Earth materials play critical roles in understanding many geophysical and geochemical phenomena, such as the temperature profile and dynamics of the mantle and subduction zones, as well as the heat flux across the core-mantle boundary. Recently we have successfully combined an ultrafast optical pump-probe method with high-pressure diamond cells to precisely measure lattice thermal conductivity of deep Earth materials under extreme conditions. We will present our recent results on the thermal conductivity of siderite, hydrous olivine, and delta (Al,Fe)OOH phases under relevant mantle pressure-temperature conditions. Modeling of our new data show potentially significant influences of hydration and iron (and its spin state) on the thermo-chemical structures and dynamics of the deep mantle and subduction zones. For instance, both hydration and iron substantially reduce the thermal conductivity of minerals; the spin transition could even induce drastic, several-fold variations in the thermal conductivity. Some future directions that are important to further understand the thermal state and dynamics of the deep Earth will also be discussed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMMR31B0076H
- Keywords:
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- 3909 Elasticity and anelasticity;
- MINERAL PHYSICS;
- 3924 High-pressure behavior;
- MINERAL PHYSICS;
- 5139 Transport properties;
- PHYSICAL PROPERTIES OF ROCKS;
- 8124 Earth's interior: composition and state;
- TECTONOPHYSICS