Final answer:
The Pacific Mountain System in North America includes the Sierra Nevada, the Cascade Range, and the Coastal Range of British Columbia. These ranges are shaped by a variety of geological processes, such as subduction and volcanic activity, leading to diverse landscapes that include iconic features like Half Dome in Yosemite.
Step-by-step explanation:
The Pacific Mountain System is a series of mountain ranges that form part of the landscape of North America's Pacific Coast, extending from Alaska to Mexico. Three prominent ranges within this extensive mountain system are the Sierra Nevada, the Cascade Range, and the Coastal Range of British Columbia.
The Sierra Nevada is a massive mountain range that stretches 400 miles across California, known for dramatic landscapes like Yosemite National Park's iconic Half Dome. This range is mainly comprised of granite batholiths that were exposed through volcanic activity, erosion, and tectonic processes such as convergence and subduction-related to plate boundaries. The geology of the Sierra Nevada has been shaped significantly by these forces within the last 5 million years.
The Cascade Range is found in the northern portion of the Pacific Mountain System, extending from Northern California through Oregon and Washington and into Canada. This chain of mountains is characterized by its numerous volcanoes, including famous peaks such as Mount Rainier and Mount Saint Helens. The creation of the Cascade Range is a result of the subduction of the Juan de Fuca and Gorda Plates beneath the North American Plate, leading to volcanic activity and the rise of the mountainous landscape.
The Coastal Range in British Columbia is another segment of the Pacific Mountain System and is part of a larger corridor known as the Pacific Wildway, which stretches from southern Alaska through these coastal mountains. This range is distinguished by its rugged and diverse terrain, supporting a variety of ecosystems and a wealth of biodiversity.