The structure of the earth’s crust of North America

North America along with Eurasia is the remnant of the ancient continent of the northern hemisphere of Laurasia, which began to split into modern continents at the end of the Mesozoic era about 100 million years ago.

The oldest and largest in area tectonic structure of North America is the North American platform, which is a fragment of ancient Laurasia. In the north of the platform, its crystalline basement faces the earth’s surface, forming the largest Canadian shield in the world. The age of the rocks, of which it consists, is about 3 billion years. The surface of the shield is flat, in many places complicated by faults and ancient outcrops of lava. In some places, the shield sinks under the waters of the ocean and again exits to the earth’s surface on the neighboring islands. To the south of the shield, the crystalline basement of the platform is gradually submerged beneath the sedimentary cover. Here the structure of the earth’s crust is complicated by depressions,

where the thickness of the cover increases.

In the south-west of the continent lies a young platform. According to the structure, this is a deep deflection of the basement, filled with a ten-kilometer layer of sedimentary rocks. The whole west of North America occupies the middle age folding belt, which mostly formed in the Mesozoic era due to the oncoming movement of the North American and Pacific lithospheric plates. Geysers, hot springs, mud volcanoes testify to recent volcanism. These phenomena are observed in the Yellowstone National Park, known for the highest geysers in the world. Some of them throw hot water at a height of 50-90 m. The Pacific coast of North America and the southern narrow part of the continent constitute a young folding belt, the process of formation of which has not come to an end. Here are the most frequent earthquakes, there are active volcanoes.

On the eastern edge of the continent, a belt of ancient folding formed in the Paleozoic era. It is a heavily damaged mountain, consisting of clastic rocks.

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The structure of the earth’s crust of North America