Scottish geologists have used sophisticated rock dating techniques to determine when a volcano in Australia last erupted.
The team from Glasgow University worked with colleagues in Australia to calculate that the Queensland volcano, part of ancient Aboriginal community folklore, last erupted around 7,000 years ago.
The research team examined rock samples from long lava flows around the Kinrara volcano in Queensland.
The flows, which are up to 34 miles long, are still clearly visible across the landscape around the volcano.
Dr Benjamin Cohen, of Glasgow University, said: “When people think of Australia, volcanoes are probably not the first thing that springs to mind, but they are actually more common than many people realise. For example, there are nearly 400 volcanic vents in north Queensland, which erupted over the last few million years, and Kinrara is one of the most recent.”
The researchers used a technique known as argon-argon geochronology to learn more about the age of the volcano. Using a noble gas mass spectrometer, they could measure the amount of argon built-up from natural radioactive decay of potassium, allowing them to determine how much time has passed since the volcano erupted.
The team’s measurements allowed them to date the Kinrara eruption to around 7,000 years ago, with the possibility that it may have been up to 2,000 years further back or forward in time.
Dr Cohen said: “The argon-argon technique we use has improved considerably in the last few years, allowing us to view the past through a sharper lens than ever before. Without those improvements, we would not have been able to determine the age of the Kinrara volcano.”
Dr Cohen’s exploration of local histories from the Gugu Badhun people uncovered a recording, made in the 1970s, of an Aboriginal elder discussing an event that sounds very much like a volcanic eruption.
The elder described a time when a pit was made in the ground with lots of dust in the air, and that people got lost in the dust and died. He also described an occurrence when the earth was on fire along the watercourses.
Dr Cohen added: “These stories are plausible descriptions of a volcanic eruption – the Kinrara volcano has a very prominent crater, which produced volcanic ash and lava fountains. The lavas from the volcano flowed 55 kilometres down the surrounding stream and river valleys, and would have looked very much like the earth burning.”