Geology of possible Martian methane source regions

Recent observations of methane on Mars suggest that spatially localized source regions are present. Here we discuss the surface morphology and mineralogy of these regions, focusing on features that may provide insights into mechanisms of methane production and/or release. Preliminary trends among methane source regions include old age, deep fractures, past or present subsurface water, and the presence of hydrated minerals, sometimes including serpentine. As the spatial and temporal coverage of Martian methane is expanded, geological observations of proposed source regions will be a powerful tool for understanding the methane cycle on modern Mars.