The visit to the Barmah Forest enabled one to see some geological history first hand. About 45,000 years ago the Murray flowed north of Echuca where the town of Mathoura is located.
Starting about 60,000 years ago a series of seismic events uplifted the Cadell fault which is clearly visible as a pronounced ridge on a flat plain and extends from around Echuca
to Deniliquin (north), consequently the Murray was dammed and a series of lakes formed in the area which is now the Barmah Forest. Initially the lakes overflowed into creeks and small rivers
that flowed to the Murray. Eventually the lakes breached the ridge near Echuca where the Goulburn enters the Murray,. The red gums became established in the lake system about 6,000 years ago.
The old stream of the Murray has steep banks whereas the Barmah Forest the banks
are flat indicated a juvenile stream. This part of the river is referred to as the Barmah Choke because the Murray is narrow and shallow. A high flow produces a flood which nurtures
the wetlands and forest; consequently the flow down river is restricted. We could not get on a boat cruise on this part of the river because it was booked out. Notes by Dick.