Fluid composition and mineral reactions at Yellowknife Bay, Mars

The Curiosity rover of Mars Science Laboratory (MSL) has identified and analysed, for the first time on Mars, a set of mudstones with nodules and Mg-rich veining, recording a history of deposition within a fluviolacustrine environment followed by low temperature alteration. The composition and mineralogical information preserved in the Gale Crater sediments provide a unique opportunity to determine the evolving composition of the fluid associated with the sediment’s diagenesis and the nature of its interaction with the surrounding rocks. In this study we constrain water/rock ratios, temperature, pH, composition and salinity of the diagenetic fluid. In particular we model the likely alteration of olivine and amorphous, allophanelike material within Sheepbed mudstone to produce the observed phyllosilicates and Fe oxides