Fig. 5: A conceptual model for forming and preserving high perchlorate/chloride ratios on the present Martian surface by coupling briny-aeolian process.
From: Cryogenic origin of fractionation between perchlorate and chloride under modern martian climate
a Aeolian processes (e.g., dust storms/dust devils) continuously transfer dust/soil particles coated with perchlorate-chloride salt mixtures (ClO4−/Cltotal ratios presumably at the global-average) in some regions (e.g., the Mars arctic region). b Under appropriate RH-T conditions, the deliquescence of the perchlorate-chloride salt mixture by interaction with water-vapor or water-ice can produce transient brines containing fractionated ClO4−/Cl− signatures. The specific ratios depend on the parent salts and the RH-T conditions. c Dust/soil particles cemented with brines would resist aeolian translocation better than dry ClO4−-depleted dust/soil particles. In this way, perchlorates preferentially accumulate in place while chlorides are more likely to be transported away.
