The mantle of Mars - Some possible geological implications of its high density

The high density of the Martian mantle probably implies an iron-rich composition expressed by a higher concentration of FeO than that in the earth's mantle. Examination of high-pressure mineralogies suggests that the model Martian mantle has an oxide-garnet wehrlite phase assemblage. This mantle model would be likely to yield ultrabasic (ferrobasaltic) melts of very low viscosity. The prevalence of low-viscosity material is consistent with large eruption rate and copious lava flow on the planet. Furthermore, ferro-kimberlite volcanic ash may be an abundant constituent in the Martian soil, especially if there was much volatile material within the early accreting Mars.