North America «drains» into the Earth’s mantle, — geologists

Researchers from the University of Texas at Austin have found that lower part of the continent North America is slowly draining into the Earth’s interior.

A new study suggests that this process may be caused by the remnants of an ancient tectonic plate Farallon, which has been submerged under the North American tectonic plate for many millions of years. The type of lithospheric plate in this region is called a craton. These are large and relatively stable areas of the Earth’s crust that have remained virtually unchanged for a long time. However, scientists are now observing for the first time the process of of cratonic thinning.

Rocks melt in the upper layer Earth’s mantle, is combined and, having gained enough mass, flows deeper thinning of the lithosphere. This process is mainly concentrated in the Midwest of the United States. However, researchers urge not to worry, as this is all happening very slowly and should eventually stop altogether, as the remnants of the Farallon tectonic plate sink deeper into the mantle and have less and less influence on the craton of the North American continent.

Scientists note that this process is extremely important for understanding how the development of our planet. The study explains how continents form and how they collapse. According to the lead author of the study, Dr Junlin Hua from the University of Science and Technology of China, which created a new full-wave seismic tomographic model for North America using an approach developed by co-author Stephen Grand, scientists have for the first time been able to observe the process of «dripping» lithospheric plates into the Earth’s mantle.

Scientists have found that an ancient oceanic tectonic plate Farallon has been sinking beneath the continent of North America for the past 200 million years. However, it played an important role in the formation of the North American plate, and now, according to researchers, is slowly destroying the continent from below, redirecting the mantle flow in such a way that it shifts the craton’s floor and releases volatile compounds that weaken its base.

Junlin Hua notes that the dripping process is mainly concentrated in the United States and Canada. The researchers also insist that the model they created is more or less realistic.

Giant waves deep in the Earth’s interior «lift» continents, — new study

The results of the study are published in the journal Nature Geoscience

Source: SciTechDaily