Washington, May 29 (Inditop): Scientists at the University of Leeds in the UK have uncovered a previously unknown giant volcanic eruption that led to global mass extinction 260 million years ago.
The eruption in the Emeishan province of south-west China unleashed around half a million cubic kilometers of lava, covering an area 5 times the size of Wales, and wiping out marine life around the world.
Unusually, scientists were able to pinpoint the exact timing of the eruption and directly link it to a mass extinction event in the study.
This is because the eruptions occurred in a shallow sea, meaning that the lava appears today as a distinctive layer of igneous rock sandwiched between layers of sedimentary rock containing easily datable fossilized marine life.
The layer of fossilized rock directly after the eruption shows mass extinction of different life forms, clearly linking the onset of the eruptions with a major environmental catastrophe.
The global effect of the eruption is also due to the proximity of the volcano to a shallow sea.
The collision of fast flowing lava with shallow sea water caused a violent explosion at the start of the eruptions – throwing huge quantities of sulphur dioxide into the stratosphere.
“When fast flowing, low viscosity magma meets shallow sea, it’s like throwing water into a chip pan – there’s spectacular explosion producing gigantic clouds of steam,” explained Professor Paul Wignall, a paleontologist at the University of Leeds.
The injection of sulphur dioxide into the atmosphere would have lead to massive cloud formation spreading around the world, which cooled the planet and ultimately resulted in a torrent of acid rain.
Scientists estimate from the fossil record that the environmental disaster happened at the start of the eruption.
“The abrupt extinction of marine life we can clearly see in the fossil record firmly links giant volcanic eruptions with global environmental catastrophe, a correlation that has often been controversial,” said Professor Wignall.
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