Seismic Science Reveals Moon’s Mantle Is Rich in Garnet

Researchers synthesized garnet-rich lunar rock assemblages to determine if sound velocities in these compositions match seismic profiles of the Moon’s deep interior.

Using high-pressure experiments, they concluded that garnet presence is compatible with observed seismic data at depths of 740-1260 km, suggesting its significant role in the Moon’s structure and dynamics.

Moon’s Interior and Garnet Presence
Our present-day Moon has an interior structure containing a central metallic core, overlain by a mantle comprised of minerals such as olivine and pyroxene (e.g. Ol+Px mantle) underneath a shell of crust (e.g. Wieczorek et al. 2006). Such a picture of the Moon’s interior has been formed from analyses of returning lunar samples and records of deep seismic events collected during missions to the Moon (e.g. Weber et al., 2011).