Work

Sound Velocities of FeO‐Bearing Ringwoodite and Majorite: Implication for Martian Mantle Seismic Profiles

Year: 2026

Type: article

Abstract: Compressional and shear wave velocities ( Vp , Vs ) of candidate Martian deep‐mantle minerals, FeO‐rich ringwoodite ((Mg 0.66 Fe 0.34 ) 2 SiO 4 ) and majorite (Mg 0.75 Fe 0.10 Al 0.26 Ca 0.07 Si 0.84 O 3 ), were measured up to 25 GPa and 700 K using Brillouin light scattering coupled with externally‐heated diamond anvil cells. Thermoelastic modeling of our results and literature data along a representative areotherm showed that Vp and Vs of FeO‐bearing ringwoodite are approximately 7.5% and 11.0% higher than that of the majorite. Our results reveal that velocity profiles of these Martian deep‐mantle minerals are more sensitive to variations in the ringwoodite/majorite (Mg/Si) ratio than to thermal and FeO chemical perturbations. Our best‐fit velocity model to a recent seismic model by Samuel et al. (2023, https://doi.org/10.1038/s41586‐023‐06601‐8 ) indicates the Martian mantle contains approximately 67 vol.% ringwoodite and 33 vol.% majorite, suggesting a ringwoodite‐rich aggregate in the Martian lowermost solid mantle. The ringwoodite‐majorite mantle likely co‐evolved with the FeO and other incompatible elements in the molten silicate layer above the Martian core‐mantle boundary.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl118991