Trentham Falls Reserve
At 32 meters Trentham falls is the highest single drop waterfall in Central Victoria. The Coliban River plunges over a basalt cliff which has cut back and formed a ravine several hundred meters long.
Millions of years ago the old Coliban River ran through a picturesque gully lined with Blackwood forest.
One day this environment was shattered and burnt as a wall of molten lava advanced northwards from a small volcano to the south completely filling the gully.
Remains of the timber and even a platypus skull have been found in the silty ash beneath the rock face.
The present Coliban River has eroded by back-cutting, once the falls were further downstream but undercutting and collapses have shifted them to their present position.
Basalt columns and whole sections of rock face collapse as spray undercuts soft river sediments.
In the near future, the area opposite the far viewing area are expected to fall. Tell-tale signs of this can be seen in water seepage's and widening cracks.
Already some large blocks have fallen reminding us that this erosion is an ongoing and natural process.
Questions
1: Roughly how long ago did the basalt flow happen and where was the volcano?
2: Approximately when were the Marine sediments that are visible beneath the falls deposited?
3: How were the rocks in the scree slope dislodged and how long ago?
4: Were the basalt columns formed under water or above? Please back up your answer with how you came to this conclusion.
I hope you enjoy your visit to this great location.
Please feel free to log at your leisure, but logs without corresponding message will be deleted.