Mt Canobolas was born about 13 million years ago (Ma) when the Orange area slowly passed over a volcanic hotspot as the Australian Tectonic Plate moved northwards, currently at a rate of 5.6 cm per year.
In a series of eruptions over about a million years volcanic lava burst through the Earth’s crust and spread up to 50 kilometres across the landscape creating the fertile soils of the Orange district.
Previous to Canobolas, around 24 Ma, the same hotspot gave rise to the Bunya Mountains in Queensland, followed by the Main Range and Toowoomba volcanics (22 Ma), also in Queensland.
By 19-18 Ma the hotspot was in northern NSW producing the Nandewar Volcanic Suite and Mt Kaputar, followed by the Warrumbungle Ranges (18-15 Ma) and finally Mt Canobolas (14-12 Ma).
Each volcano in this chain formed tall isolated cone-shaped mountains that provided ideal conditions for the evolution of new plant and animal species.
For example, we know that four species of native land snails are restricted to Mt. Kaputar in northern NSW and that each extinct volcano supports a set of endemic plant species that occur nowhere else.
At the moment we do not know whether Mt Canobolas has its own set of land snails because no-one has looked, but we do know that at least nine endemic plant and animal species occur only on Mt Canobolas.
The tragedy of Mt Canobolas is that almost all of the original bushland of the volcanic complex has been cleared and the unique biodiversity of the mountain is clinging to survival in just 1,672 ha in the State Conservation Area.
By contrast, much larger bushland areas are protected around the other extinct volcanos on the hotspot track, including Warrumbungle National Park (23,300 ha), Mt. Kaputar National Park (36,800 ha), Main Range National Park (18,400 ha) and Bunya Mountains National Park (11,700 ha).
Mt Canobolas is the last link on the central volcano hotspot track and is every bit as important for its geology and biodiversity as iconic places such as the Warrumbungle Ranges and Mt Kaputar. Sadly, the unique biodiversity of Mt Canobolas is the most threatened owing to the tiny area of uncleared land that remains.
It is imperative that the utmost protection is afforded to this extraordinarily valuable area.
Read the letter in the Central Western Daily.
Dr Colin Bower
Take Action Now