 The two cratons consist of crust dating from 2.7 to 3.6 Gya, which would make Vaalbara one of Earth's earliest supercontinents.There has been some debate as to when and even if Vaalbara existed.An Archaean-Palaeoproterozoic (2.8–2.1 Gya) link between South Africa and Western Australia was first proposed by in 1976.