Have olivine, will gas: Serpentinization and the abiogenic production of methane on Mars

Spatial variability of methane (CH4) on Mars suggests the presence of localized subsurface sources. Here, we show that olivine hydration in the Martian regolith and crust may be a major CH4 source, which contributed significantly to the warming of early Mars. Methane production is kinetically and thermodynamically favored during low-T aqueous alteration of olivine-rich rocks. Sustained release of CH4 on present-day Mars may come through the breakdown of ancient CH4 hydrates and from springs driven by geothermal heat.