The detection of phyllosilicates, sulfates, chlorides, carbonates and silica minerals on Mars implies dissolution of primary rocks and aqueous transport of elements. However, aqueous fluids are not stable at the present surface, and observed minerals could have formed in the past. We will use numerical geochemical models to evaluate chemical processes that could have led to observed mineral assemblages. In particular, effects of atmospheric composition, volcanic and impact degassing, uneven mineral dissolution, evaporation and freezing will be considered. Our models couple kinetics of mineral dissolution with chemical equilibrium computations. The results will yield estimates of pH, oxidation states, concentrations and activities of solutes, and amounts of secondary and unaltered minerals as functions of the progress of water-rock reactions in time. Results of modeling will be interpreted in terms of observed secondary mineralogy and geochemistry of the martian surface.
|Effective start/end date||4/1/13 → 9/30/16|
- NASA: Goddard Space Flight Center: $264,387.00