History revealed at Toowoomba Bypass pilot tunnel
The term “as old as the hills” has a new meaning thanks to a special study of the Toowoomba Bypass pilot tunnel.
Our geology team has been working with University of Queensland's research geologist, Ben Cohen, to investigate the geochronology, the age of rocks, at the north Toowoomba site.
Testing has pinpointed the rocks’ age to be 23 million years old, up to four million years older than anticipated.
However, rock samples from another Toowoomba site tell a different story.
These were dated at more than 40 million years old. This is twice the age that was previously thought, proving there were more ancient volcanic eruptions close by.
Our senior engineering geologist in southern Queensland, Ron Bathurst, acknowledges how important the study is, as there was a gap in accurate information about the geological history of Toowoomba.
“The new data the University of Queensland is providing helps us to better understand the site so we can be more prepared for the construction stage,” he said.
The Toowoomba Bypass pilot tunnel was completed in January 2008.
The tunnel was used to assess the geology and hydrology in the Toowoomba range escarpment. This is where twin three-lane tunnels are planned as part of the full bypass.
A decision is yet to be made on when construction of the bypass might start.
Last updated: 27 October 2009
