Ancient Volcanoes Discovered In Lost ‘Jurassic World’ Beneath Australia

Volcanoes in the Jurassic were much like today, but there were around 100 of them in central Australia, and possibly many more beyond the area explored. Ranier Albiez/Shutterstock

Deep beneath Australia geologists have discovered a Jurassic world. Sadly, it doesn't contain any living dinosaurs (and probably few dead ones either) but it does have more volcanoes than a Hollywood director's dream, even if they've been extinct for well over a 100 million years.

The Cooper-Eromanga Basin underlies what are now some of the driest parts of Australia. It's Australia's largest onshore oil and gas producing region, and while its fossil fuels are fairly paltry by international standards that still means its geology has been more heavily explored than many other parts of the continent. Despite this, no one noticed at least 100 remarkably well preserved extinct volcanoes within the Basin.

The volcanoes were active 180-160 million years ago. Their presence was somewhat unexpected because most volcanoes occur at the edges of tectonic plates, but these existed in an area that was as much mid-plate then as it is today.

Dr Simon Holford of the University of Adelaide told IFLScience that, besides no one anticipating them, the volcanoes were missed through 60 years of oil exploration in part because exploration methods haven't been well suited to finding volcanic provinces. Holford's team has developed world-leading techniques for detecting the signal from ancient volcanoes in seismic reflection surveys, and ended up finding a province close to home.

In the journal Gondwana Research, Holford and colleagues named the province Warnie, in part for a local waterhole that gave its name to an exploration drill site important to their findings, but also for the legendary Australian cricketer Shane Warne. Holford told IFLScience that as an English-born obsessive cricket fan he can't bring himself to support his adopted country despite 12 years of residence, but thought the vast fields of volcanoes reminiscent of Warne's explosive talent and fiery temperament.

Deep beneath Australia's core, seismic reflections reveal buried volcanoes from the age of the dinosaurs. Hardman et al/Jurrasic Research

Although the province was surrounded by mighty rivers in its heyday, if these wiped out any volcanoes from the geological record there were plenty left. The rest were buried under a heavy load of protective sediment as this part of the continent sank.

Holford told IFLScience the work has some commercial applications. “Drilling through volcanic rock is harder and more expensive than through sediments,” he said. “The drill bits keep wearing out.” By identifying the location of these rocks the findings will make it easier for those seeking underground resources, whether natural gas, water or hot rocks for geothermal energy, to find the path of least resistance.

Sadly, however, Holford doubts there will be much paleontological benefit. Drilling rigs make holes so narrow the chance of them hitting a fossil is small at the best of times, and Holford noted Australia's Cretaceous rocks have been a much richer source of dinosaur bones than those of Jurassic age.

Comments

If you liked this story, you'll love these

This website uses cookies

This website uses cookies to improve user experience. By continuing to use our website you consent to all cookies in accordance with our cookie policy.