Part of the Mesoarchean Era
Isuan Period - Vaalbaran Period - Pongolan Period
The Vaalbaran Period is the first period of the Mesoarchean Era and the third of the Archean Eon. The Vaalbaran begins at the time from which the oldest macroscopic fossils - stromatolites - are known and ends at the time from which the oldest terrestrial basins are known. The oldest ascertained lifeforms - well preserved bacteria dated at around 3460 MYA - are known from this period, though all evidence suggests that life had already existed for nearly one billion years before that. The supercontinent of Vaalbara - the namesake of the period - had already began to assemble during the Isuan Period, a process that would be completed at around 3100 MYA.
The Vaalbaran is not further subdivided into epochs.
Vaalbaran Timescale:
Vaalbaran Period - 3490-3020 MYA