Constraints on the formation of carbonates and low‐grade metamorphic phases in the Martian crust as a function of H ₂ O‐CO ₂ fluids

Low-grade metamorphic hydrous minerals and carbonates occur in various settings on Mars Martian meteorites. We present constraints the stability of prehnite, zeolites, serpentine, by modeling influence H2O-CO2 fluids during low-grade metamorphism crust using compositions a basalt an ultramafic cumulate. In basaltic with 5 wt% fluid, our models predict prehnite less oxidized, CO2-poor conditions (≤0.44 mol kg−1 CO2) warmer geotherms 20 °C km−1. At fluid-saturated conditions, epidote laumontite are replaced quartz, calcite, chlorite, muscovite. antigorite (serpentine) is stable at ≤0.33 kg−1, while talc forms 0.05–0.56 CO2. higher X(CO2) magnesite quartz. Our therefore suggest that serpentine have formed environment implying their formation either did not contain high amounts CO2 or had degassed Carbonates potentially would presence CO2-bearing fluid different alteration stages than for same hydrothermal event which composition changed gradually due to cooling precipitation separate successive events compositions.