Final answer:
The Western margins of America are part of the Cordilleran orogenic belt, encompassing a series of mountain ranges and geologic processes related to plate tectonics that extends from Alaska to Mexico.
Step-by-step explanation:
The Western margins of America are part of the Cordilleran orogenic belt. This refers to areas affected by the various geological processes associated with plate tectonics, specifically the movement and collision of the Earth's lithospheric plates, which resulted in the creation of mountains. The Cordilleran orogenic belt outlines a series of mountain ranges and related geologic phenomena that span from Alaska through western Canada and the United States to Mexico. This area contrasts with the Eastern Provinces of the United States, which are defined by older orogenic events and generally older geological formations such as the Appalachian Highlands.
The geologic history of these margins is fascinating and reflects the dynamic processes that shape our planet's crust. For example, the formation and continental rifting that separated Pangea into the current continents, including North and South America, played a key role in the development of these features. The geologic provinces in the Western United States represent a tectonically active region characterized by the Rocky Mountains, the Coastal Pacific Mountain System, Interior Plateaus, and the extensional Basin and Range areas. Each of these regions tell a complex story about the geological past and the forces that have shaped not only the land but also the biological and cultural history of the region.