An era in the Archaean eon, 3600–3200 Ma ago, preceded by the Eoarchaean and followed by the Mesoarchaean eras. Fossil stromatolites and other indirect evidence of life are dated to this time, and it is possible that the first supercontinent, Vaalbara, formed around 3200 Ma ago, its name derived from the Kaapvaal craton in southern Africa and the Pilbara craton in Western Australia; palaeomagnetic data indicates that during the Palaeoarchaean these were close together.