When Pangaea split up, what happened to the western edge of the North American continent?
When Pangaea split up, the western edge of the North American continent went through significant changes. The breakup resulted in the formation of a new tectonic boundary known as the West Coast or Pacific Coast. This boundary is along the western edge of North America, stretching from Alaska down to the southern tip of South America.
As Pangaea began to break apart around 200 million years ago, the process of continental drift led to the separation of North America from other land masses. The western edge of North America was involved in the formation of new tectonic plates, including the Pacific Plate and the North American Plate. This separation created the San Andreas Fault, a prominent transform boundary that runs through California.
Over millions of years, the movement of these tectonic plates along the West Coast has resulted in various geological features. These include the formation of the Sierra Nevada mountain range, the coastal mountain ranges such as the Cascade Range, the Rocky Mountains, and the volcanoes in the Pacific Northwest like Mount Rainier and Mount St. Helens.
Additionally, the Pacific Plate's subduction beneath the North American Plate has given rise to the Cascade Volcanic Arc, which includes notable volcanoes like Mount Shasta, Mount Hood, and Mount St. Helens. The western edge of North America has also experienced intense uplift and erosion, resulting in the creation of deep river canyons such as the Grand Canyon.
In summary, when Pangaea split up, the western edge of the North American continent went through significant geological transformations, including the formation of the West Coast, the creation of tectonic boundaries such as the San Andreas Fault, the formation of mountain ranges, and the emergence of prominent volcanic activity in the Pacific Northwest.