Farallon: how lithospheric plates die

Many people know the main points of the theory of lithospheric plates, which explains the surface structure of our planet and the peculiarities of the location of the main zones of seismic activity. In the spreading zones, a new crust is emerging. And in the subduction zones, the plates slowly sink one below the other, and this process is accompanied by frequent earthquakes, as well as the presence of active volcanoes. But what happens to the submerged fragments of these plates next? Where do they disappear when they fall under an adjacent stove? This can be found in the example of a large ancient Farallon plate, which today is preserved only in the form of several small fragments.

The Farallon plate was composed of an oceanic crust and existed relatively recently by geological standards, about 200-150 million years ago. The plate was located in the northeast of the Pacific Ocean and moved towards the North American plate. In the place where the two large plates met, the Farallon plate sank beneath its neighbor. This process has continued for millions of years. During this time, dinosaurs disappeared, large mammals appeared in the seas, and on land many species of birds, animals and human civilization arose.

Slowly plunging under the North American plate, the ancient plate gradually sank into the mantle of our planet. Under the influence of high temperatures, the crust collapsed and transformed, breaking up into separate fragments, some of which are still under the continent of North America. Geographically, the ancient Farallon plate is today under the eastern states of the United States, and the remains of the plate were discovered by geologists using seismic tomography methods.

In the immersion zone of the ancient Farallon plate, as in other similar regions of the planet, there is an extended region of seismic activity, which repeats the contours of the subduction site. The well-known San Andreas Fault and Yellowstone Super Volcano are confined to this core. Scientists consider the modern fragment of the huge Farallon plate to be the plate of Juan de Fuca, which, like its predecessor, continues to sink under the North American plate.

The transformation of the Farallon plate clearly demonstrates what happens to those lithospheric plates that do not withstand the onslaught of their neighbors and plunge into the bowels of the Earth. The study of the processes associated with this ancient stove has not only scientific significance, but also practical interest. The fact is that the evolution of this plate is important for understanding a wide range of seismic manifestations in western North America. Large fragments of the plate located under the continent directly affect the flow of magmatic matter from the bowels of the planet, and scientists attribute the activity of the Yellowstone volcano to the presence and displacement of fragments of the Farallon plate.