Find out how tall George Washington is! To help visualize his height, we've included a side by side comparison with other founding members of the United States, short and tall!
Upwarped mountains are generally the result of broad arching of the crust or sometimes great vertical displacement along a highangle fault. The Black Hills in South Dakota and the Adirondack Mountains in New York are upwarped mountain ranges. Volcanic mountains are the accumulations of large amounts of volcanic lavas and pyroclastic material around the volcanic vent, such as seamounts and stratovolcanoes. The Hawaiian and Aleutian Islands are volcanic mountains. Fault-block mountains result from tensional stress.
Whilst most volcanic activity happens at plate margins, there are cases of volcanoes erupting in the middle of plates. The Hawaiian Islands are formed by volcanic activity, despite the nearest plate margin being 3,200 km away. Some geologists have suggested that a 'hot spot' in the mantle, which remains stationary as the Pacific Plate moves over it, explains the existence of the island chain. The hot spot may represent the top of a mantle plume which originated deep down at the outer core - lower mantle boundary.