Coonterunah Subgroup, Australia
The Coonterunah Subgroup is one of the oldest well-preserved supracrustal sequences known on Earth. Located in the Pilbara Craton, Western Australia, the sequence is about 5 km in stratigraphic thickness and exposed over about 75 km strike length. It consists mainly of tholeiitic and minor komatiitic basalt, some felsic lava with intercalated carbonate, and chert beds. It is 3.52 Ga old and its metamorphic grade is only mid-greenschist to lower amphibolite facies. It contains sedimentary carbonate and kerogen that may represent some of the oldest traces of life on Earth.