Isotope dating of rocks
This event divided the drainage of the area affected into a coastal region, where the rivers still flow to the sea, and the Plateau region.
Uplift occurred at about the end of the Cretaceous, 65-60 Ma, in the Canning and Officer Basins.
This shows that the palaeodrainages were formed earlier than Late Eocene.
On the western margin, the Beaufort and Darkan palaeochannels are the first fairly complete palaeochannels found to be flowing east to west in the south-western sector of the Yilgarn Craton.
The granite of these outcrops is very weather-resistant, and hence erosion-resistant, both because the rock is very hard and because many of the outcrops are solid masses with few or no cracks or faults that the forces of erosion can work on.
It was one of the blocks of crust, cratons, which were later joined together to form the present continent of Australia, at a much later date It has been accepted, based on dates of meteorites that were believed to have formed from the same dust and gas cloud that the Earth formed from, that the age of the earth was 4550 million years.It was assumed that the bombardment of the Earth by meteorites that were swept up as the Earth moved along its orbit would have been sufficiently intense to keep the Earth molten until 4030 million years ago, which is the age of the oldest known rocks from Canada.Then detrital zircon crystals were found in metamorphosed rock at Mt.Glaciers ground their way across the Yilgarn Plateau from about the Late Carboniferous to the Early Permian.Immediately after the glaciers there was no organised drainage system, any there before the glaciation were ground out of existence by the glaciers.