Touring the ancient Lake Bunyan
Touring the ancient Lake Bunyan
The geological history of the Numeralla region unveiled in a workshop and tour of the region.
Community Participation -
LEP23 - 014_LLC12_1
The issue
Many are unaware of the history beneath our feet, despite the influence these geological landforms have on our everyday life. The Numeralla region supports a number of distinct geological features carved from the ancient Lake Bunyan. Lake Bunyan was around 8km wide and 30km long that formed when the Murrumbidgee River became fault‐dammed 5 km south of Bredbo around 23 million years ago. The lake existed for over 18 million years until a breach saw it flow into the Murrumbidgee River. What remains tells this story and determines the characteristics of the soils that we use.
The solution
Numeralla Landcare and ANU expert, Leah Moore, took residents through an ancient tour of Lake Bunyan and taught us how to read the landscape. Leah explained the forces throughout time that laid down the different sediments and the information that scientists can learn from each layer. A tour then took everyone out to play with some dirt. The lake edge, which corresponds with the 780m contour line was well demonstrated and the properties of the different soils were visible. We could see sodic soils dissolving in front of our eyes and standing on the ancient lake edge was a great way to read our current landscape.
The impact
The opportunity to learn about the geological history of the places that we live is often limited but an understanding of what that means for today’s landscape can help with how we manage our land. The information provided throughout the day unveiled the history of the sediments and allowed people to assess how these processes impact them now. Lake Bunyan is no longer out of site and out of mind.
Key facts
- Ancient geological processes carved our current landscapes
- Understanding our sediments helps manage our soils more effectively
- Lake Bunyan would have been impressive