Abstract Aluminum is a key component of crustal and mantle minerals, influencing melting and geochemical evolution within the Earth. Al2O3 exists as corundum at the surface and in upper mantle conditions, but transforms into high‐pressure phases like Rh2O3(II) at lower mantle depths, enabling stability over a wide pressure range. It is also a dominant phase in anorthositic lithologies, which may represent remnants of Earth’s early crust and contribute to deep mantle heterogeneities. We calculate the thermoelastic properties of these Al2O3 phases and model their behavior in mantle lithologies such as anorthosite, mid ocean ridge basalt, and pyrolite along relevant geotherms. Results suggest that Al2O3 could persist as Rh2O3(II) within Large Low Shear Velocity Provinces and the Dʺ layer, while corundum could remain stable in high‐velocity zones. Integrating these phases into multiphase assemblage provides new constraints on deep mantle composition and supports the idea of preserved primordial crustal materials in the lower mantle.
Last updated: April 18, 2026 04:26 PM
CO₂
429.8ppm
+-0.2
/ year
CH₄
1945.85ppb
+8.44
/ year
Temp
+1.48°C
Peak +1.73°C
Population
8.1B
+67M
/ year