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Australia’s Record-Breaking Volcano Chain

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The world’s longest known chain of continental volcanoes has been uncovered, running 2000 km across Australia from the Whitsunday Islands in north Queensland to central Victoria. The volcanic chain was created over the past 33 million years as Australia moved northwards over a hotspot in the Earth’s mantle.

“We realised that the same hotspot had caused volcanoes in the Whitsundays and the central Victoria region, and also some rare features in New South Wales roughly halfway between them,” said Dr Rhodri Davies of The Australian National University. “The track is nearly three times the length of the famous Yellowstone hotspot track on the North American continent.”

This kind of volcanic activity is surprising because it occurs away from tectonic plate boundaries, where most volcanoes are found. The hotspots are thought to form above mantle plumes, narrow upwellings of hot rock that originate at the boundary between the Earth’s core and mantle almost 3000 km below the surface.

The study, published in Nature, found that sections of the track have no volcanic activity because the Australian continent is too thick to allow the hot rock in the mantle plumes to rise close enough to the Earth’s surface for it to melt and form magma. The plume only created volcanic activity where the Earth’s solid outer lithosphere was thinner than 130 km.

The findings...

The full text of this article can be purchased from Informit.