According to new research, a sub-underground ‘conveyor belt’ of magma pushed across the Earth’s surface for millions of years was responsible for the longest stretch of supervolcanoes ever seen.
Researchers said a change in seabed led to channels through which magma could flow freely. This resulted in an extensive period of explosions from about 122 million years ago to 90 million years ago; Extraordinary, given that these types of flows typically last only 1–5 million years.
It all happened on the Kerguelen Plateau, which now sits under the Indian Ocean. It is known as a large igneous province or LIP, which is a widespread accumulation of magma and lava. Scientists can use these LIPs to detect volcanic activity through time.
Geologist Qian Jiang of Curtin University in Australia states, “Extremely large accumulations of volcanic rocks – known as large volcanic provinces, due to their link with mass extinctions, rapid climatic disturbances and ore deposits Are very interesting for scientists. “
Jiang and his colleagues used samples of black basaltic rocks taken from the ocean floor, together with an argon isotope dating method to determine the spread and growth of LIP, as the mantle plume formed by growing magma. Is known in
Researchers say that during 30 million or so years of intense activity, the Kerguelen plateau grew by about 20 centimeters (7.87 in). Across the vast size of the LIP – nearly three times the size of Japan – the outpost is equivalent to 184,000 Olympic-sized swimming pools filled with lava per year.
The Kerguelen Plateau saw such a long and steady run of supervolcanoe activity due to its unique configuration, the study suggests: a mantle plume combined with slow-spreading mid-ocean ridges moves magma upward.
Geologist Hugo says, “The volcano lasted so long because the magma was constantly flowing through the Middle Ocean streaks due to the mantle plume, which continuously acted as a channel, or ‘magma conveyor belt.’ Orlyuc, from Curtin University .
“Other volcanoes will stop bursting because, when the temperature cools, the channel becomes filled with ‘frozen’ magma. For the Kerguelen plateau, the mantle plume acts as a Bunsen burner, melting the mantle Allows, resulting in exceptionally long stays. Blast activity. “
This is the activity of volcanic eruptions over many millions of years, but this rate had dropped significantly around 90 million years ago, and scientists are still not sure why. Associated volcanic activity continues today, on a much smaller scale.
This is a fascinating look at our planet’s past history, and certainly it informs our study of volcanic activity even in the present day – the more we know how such systems can form and remain active. , We can understand better. There are talks under the surface of the Earth right now.
“This long-term, persistent eruption activity is important because it helps us understand what factors can control the beginning and end of volcanic activity,” says geocronologist Fred Jersdan of Curtin University.
“It means how we understand magmatism on Earth and also on other planets.”
The research has been published in Geology.