Jarosite stability on Mars

Alexandra Navrotsky (1) , Ferenc Lázár Forray (1) , Christophe Drouet (2)

1 CHE - UC Davis - Department of Chemical Engineering [Univ California Davis]
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

Jarosite, a potassium (sodium) iron sulphate hydrated mineral, has recently been identified on the martian surface by the Opportunity rover. Using recent thermochemical data [Drouet and Navrotsky, 2003, Geochim. Cosmochim. Acta 67, 2063–2076; Forray et al., 2005, Geochim. Cosmochim. Acta, in press], we calculate the equilibrium decomposition curve of jarosite and show that it is thermodynamically stable under most present martian pressures and temperatures. Its stability makes jarosite potentially useful to retain textural, chemical, and isotopic evidence of past history, including possible biological activity, on Mars.

Mots clés: Mars climate; Mineralogy; Jarosite; Mineral stability; Mars climate

Domaines: Matériaux

Alexandra Navrotsky, Ferenc Lázár Forray, Christophe Drouet. Jarosite stability on Mars. Icarus, 2005, 176 (1), pp.250-253. ⟨10.1016/j.icarus.2005.02.003⟩. ⟨hal-03601625⟩