 As Eridania Lake dried out in the late Noachian epoch it divided into a series of smaller lakes.Later research with CRISM found thick deposits, greater than 400 meters thick, that contained the minerals saponite, talc-saponite, Fe-rich mica (for example, glauconite-nontronite), Fe- and Mg-serpentine, Mg-Fe-Ca-carbonate and probable Fe-sulphide.The Fe-sulphide probably formed in deep water from water heated by volcanoes.