BACKGROUND

The geomorphology of the parklands is among the most diverse and accessible in metropolitan Melbourne. Sandstone, siltstone and mudstone were laid down when the area was part of a vast seabed some 450 million years ago.

 

Subsequent uplifting, warping, erosion, volcanic activity and human influences have shaped the landscape of the parklands and surrounds. The western end of the parklands incorporates a large portion of the Chandler flood basin; the flood basin was created 2 million years ago when lava flowing down the Darebin Creek partially blocked the Yarra River and caused the area to flood. The resulting sedimentation produced a large number of billabongs that were carved in the flood basin as the Yarra River created a new channel south of Ivanhoe.

 

As a result of their proximity to Melbourne, many floodplain wetlands have been cleared, filled-in for agricultural and urban development, or lost when their water source was diverted. The Yarra River still regularly floods into wetlands such as Bolin Bolin Billabong, Banyule Wetlands and the Annulus, but for much shorter periods of time.

 

Further upstream, east of the Plenty River confluence, there are uplifted areas that expose the underlying geology. In a number of places along this section of the river there are small islands, rapids and cliffs.