CRISM: Mafic minerals in Nili Fossae

The vast majority of the planet’s crust is unaltered igneous rock although there are some occurrences of aqueously altered rocks linked to past water activity. The colors here show concentrations of different minerals common in rocks that might tell us about processes that happened in Mars’ past. The green/cyan color denotes a variety of a mineral called pyroxene that has an unusually low content of… [More at link]