The formation is more than 300 metres (980 ft) thick^[2] and is part of the Mount Sharp Group which interfingers with units of the Bradbury Group.^[3] The formation is composed mostly of basaltic minerals plus clays, though an intermediate horizon contains tridymite, cristobalite, quartz and opal.^[4]

The Murray formation has five named subunits, the Pahrump Hills Member, Hartmann's Valley Member, Karasburg Member, Sutton Island Member, and Vera Rubin Ridge Member.^[2] It unconformably underlies the Stimson formation.^[5]

The Murray formation is the target of multiple compelling hints of ancient Martian microbial life. The region contains veins of boron^[6]^[7] and "halos" of silica likely formed by groundwater flows late in the crater's geologic history^[8] and high levels of manganese oxide suggesting Earth-like oxygen levels early in Mars' history.^[9]

Stratigraphy

References