Slowing of continental plate movement controlled timing of Earth's largest volcanic events

Scientists have shed new light on the timing and likely cause of major volcanic events that occurred millions of years ago and caused such climatic and biological upheaval that they drove some of the most devastating extinction events in Earth's history.

Surprisingly the new research, published in leading international journal Science Advances, suggests a slowing of continental plate movement was the critical event that enabled magma to rise to the Earth's surface and deliver the devastating knock-on impacts.

Earth's history has been marked by major volcanic events, called Large Igneous Provinces (LIPs) - the largest of which have caused major increases in atmospheric carbon emissions that warmed Earth's climate, drove unprecedented changes to ecosystems, and resulted in mass extinctions on land and in the oceans.

Using chemical data from ancient mudstone deposits obtained from a 1.5 km-deep borehole in Wales, an international team led by scientists from Trinity College Dublin's School of Natural Sciences was able to link two key events from around 183 million years ago (the Toarcian period).

The team discovered that this time period, which was characterised by some of the most severe climatic and environmental changes ever, directly coincided with the occurrence of major volcanic activity and associated greenhouse gas release on the southern hemisphere, in what is nowadays known as southern Africa, Antarctica and Australia.

On further investigation - and more importantly - the team's plate reconstruction models helped them discover the key fundamental geological process that seemed to control the timing and onset of this volcanic event and others of great magnitude.

Micha Ruhl, Assistant Professor in Trinity's School of Natural Sciences, led the team. He said: "Scientists have long thought that the onset of upwelling of molten volcanic rock, or magma, from deep in Earth's interior, as mantle plumes, was the instigator of such volcanic activity but the new evidence shows that the normal rate of continental plate movement of several centimetres per year effectively prevents magma from penetrating Earth's continental crust.

"It seems it is only when the speed of continental plate movement slows down to near zero that magmas from mantle plumes can effectively make their way to the surface, causing major large igneous province volcanic eruptions and their associated climatic perturbations and mass extinctions.

"Crucially, further assessment shows that a reduction in continental plate movement likely controlled the onset and duration of many of the major volcanic events throughout Earth's history, making it a fundamental process in controlling the evolution of climate and life at Earth's surface throughout the history of this planet."

The study of past global change events, such as in the Toarcian, allows scientists to disentangle the different processes that control the causes and consequences of global carbon cycle change and constrain fundamental Earth system processes that control tipping points in Earth's climate system.

The research was conducted as part of the International Continental Drilling Programme (ICDP) Early Jurassic Earth System and Timescale (JET) project, and financially supported by the SFI Research Centre in Applied Geosciences (iCRAG), the Natural Environment Research Council UK (NERC), the National Science Foundation China, and the EU Horizon 2020 programme.

Research Report:Reduced plate motion controlled timing of Early Jurassic Karoo-Ferrar large igneous province volcanism

Related Links
Trinity College Dublin
Tectonic Science and News

Tweet

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only

SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Diamonds and rust at the Earth's core-mantle boundary
Tempe AZ (SPX) Sep 06, 2022
Steel rusts by water and air on the Earth's surface. But what about deep inside the Earth's interior? The Earth's core is the largest carbon storage on Earth - roughly 90% is buried there. Scientists have shown that the oceanic crust that sits on top of tectonic plates and falls into the interior, through subduction, contains hydrous minerals and can sometimes descend all the way to the core-mantle boundary. The temperature at the core-mantle boundary is at least twice as hot as lava, and high eno ... read more