International research led by geologists from Curtin University has found that one volcanic province in the Indian Ocean that is most active in the world ̵1; erupting for 30 million years – is powered by energy. by a continuously moving magma conveyor.
It is believed that this magma conveyor belt, created by displacement of the seabed, continuously created space for molten rock for millions of years, starting about 120 million years ago.
Dr Qiang Jiang, lead research candidate from Curtin School of Earth and Planetary Science, said the volcanoes studied is located in the Kerguelen Plateau, located in the Indian Ocean, about 3,000 miles from Fremantle, Western Australia km to the southwest.
“The massive accumulation of volcanic rocks – known as major volcanic provinces – is very interesting to scientists due to their connection to mass extinction, gas turbulence,” Jiang said. rapid post-production and mine formation ”.
“The Kerguelen Plateau was enormous, almost the size of Western Australia. Now imagine this land covered with lava, several kilometers thick, erupting at a rate of about 20 centimeters per year. Twenty A year of lava may not sound like much, but, on an area the size of Western Australia, that is the equivalent of filling 184,000 Olympic-sized swimming pools ashore with lava each year. That’s the equivalent of 5.5 trillion lava-filled swimming pools! This volume has been active for 30 million years, making the Kerguelen Plateau the site of the longest continuous eruptions on Earth. the eruption rate then plummeted about 90 million years ago, for reasons not yet fully understood. Since then, a slow but steady flow of lava continues to this day, including the eruption. The 2016 movement involves the Big Ben volcano on Heard Island, Australia’s only active volcano.
Co-researcher, Dr. Hugo Olierook, also from the Curtin School of Earth and Planetary Sciences, explains that such a long eruption time requires very special geological conditions.
“After the Gondwana supercontinent was partially divided into what is now known as Australia, India and Antarctica, the Kerguelen Plateau began to form on top of a mushroom mantle, called a mantle, as well as along the deep, middle – ocean crust edges, “said Dr. Olierook.
“Volcanoes last too long because the magma created by the mantle continuously flows out across the mid-ocean ridges, continuously acting as a channel or ‘magma conveyor’ for more than 30 million years. Other volcanoes will continue. ceases the eruption because, when the temperature cools, these channels are clogged with ‘freezing’ magma. For the Kerguelen Plateau, the coating acts as a continuous Bunsen burner allowing the coating to melt. flowing, resulting in unusually long eruptions. “
Study co-author Professor Fred Jourdan, Director of the Western Australian Argon Isotope Facility at Curtin University, said the team used the argon-argon dating technique to date the clones. lava, by analyzing a series of black basalt rocks taken from the bottom of the seabed.
“Finding this long, continuous eruption is important because it helps us understand what factors control the beginning and end of volcanic activity,” said Prof Jourdan. “.
“This has implications for how we understand magma on Earth and on other planets.”
The research paper, “The longest continuous volcanic eruption spurred by the plume-ridge interaction,” is published in Geology.
The supercontinent rift forms strange Bunbury rocks
Qiang Jiang et al. The longest continuous eruption of great fire was motivated by the interaction between the feathers, Geology (Year 2020). DOI: 10.1130 / G47850.1
Provided by Curtin University
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