Volcano Chain Recently Discovered In Australia Said To Be Longest Continental Span at 2,000 Kilometers
A volcano chain spanning 2,000 kilometers was found in Australia, and is considered the longest known chain of continental volcanoes in the world, according to researchers from the Australian National University (ANU). The volcanic chain, named the Cosgrove hotspot track, runs from the islands of Whitsundays in North Queensland, to Melbourne in the central Victoria region.
"We realized 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," Dr. Rhodri Davies, lead researcher from ANU's research school of earth sciences, said in a news release.
Dr. Davies also noted that, the volcanic chain formed over the past 33 million years, as a result of Australia moving north over a hotspot in Earth's mantle.
"The track is nearly three times the length of the famous Yellowstone hotspot track on the North American continent," he said in the release.
Unliek most volcanoes, this volcanic chain does notexist along tectonic plate boundaries. Hot spots form over mantle plumes, which are upwellings of molten rock that originate roughly 3,000 kilometers below Earth's surface.
Some sections of this newly discovered volcanic chain were found to be inactive. According to the researchers, this is because the Australian continent is too thick, beyond 130 kilometers thick, and prevents plumes from rising, melting and forming magma.
"Ultimately this new understanding may help us to reconstruct the past movements of continents from other hotspots," Dr. Davies said in a statement.
Chemical composition of magma might also help them connect the dots. A mineral known as leucitite was found in active areas of New South Wales overlying the volcanic chain. According to the researchers, areas with this unusual mineral represent those that are thin enough to allow the mantle plumes to melt.
Professor Ian Campbell, co-author from ANU's research school of earth sciences, explained that leucitite is found in low-volume magmas that are rich in elements such as potassium, uranium and thorium. He said this provides a direct relationship between the volume and chemical composition of magma and the thickness of the continent. This will help scientists better interpret the geological record in the future.
Their findings were recently published in Nature.
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