North America
Continent is sinking into the earth’s cloak due to a piece of a tectonic plate that began to separate 20 million years ago.
Part of an ancient oceanic tectonic plate under the Midwest is causing parts of the North America crust to sink into the earth’s cloak.
The phenomenon, which says the continent is “draining” down, was described in a new study in Nature Geoscience in late May.
The team led by Junlin Hua from the University of Science and Technology of China found that a section sunk from ancient Farallon plate It is pulling down parts of the American crust.
The slab, located about 660 kilometers below the surface, is located between the cloak transition zone and the lower cloak. Acts as a giant funnelattracting material horizontally from places as distant as nebraska, Michigan and Alabama, before pulling it vertically into the earth.
This process is causing a widespread “cratic tuning”, a rare geological phenomenon in which the most stable parts of the continent – known as crackers – They are being slowly eroded from below.
Rocks to drip from the Cratão.
The cracks are the old and stable nuclei of the continents and are typically resistant to geological change, explains the. His erosion has never been directly observed due to the immense time -scales involved, but the new study documents, for the first time, the phenomenon in real time.
The Frarallon plate, once part of a huge subduction zone along the western coast of North America, began to separate about 20 million years ago due to the advance of the Pacific plate. His remains sinked under North America and remained hidden under the underground. One of these pieces is now exerting a descending force that has created huge underground “leaks”, pulling the bottom of the continent into the cloak.
Researchers built models that simulate the effect of the slab on the over -disrupting crust, which showed that the process was only occurring when the Plaque of Farallon was present, which confirms that it is the “guilty”.
Although the phenomenon occurs far below the surface and is not likely to affect life to the surface in the near future, “help us understand how continents are created, how they depart and how to recycle,” said study coautler Thorsten Becker, a geophysics expert at UT Austin at.
