what plate is the sierra nevada mountains on
Sierra Nevada (U.S.) In the Cretaceous, a subduction zone formed at the edge of the continent.[20] This means that an oceanic plate started to dive beneath the North American plate. Magma formed through the subduction of the ancient Farallon Plate rose in plumes (plutons) deep underground, their combined mass forming what is called the Sierra Nevada batholith. These plutons formed at various times, from 115 Ma to 87 Ma.[21] The earlier plutons formed in the western half of the Sierra, while the later plutons formed in the eastern half of the Sierra.[18] By 66 Ma, the proto-Sierra Nevada had been worn down to a range of rolling low mountains, a few thousand feet high.
Rocky Mountains The Rocky Mountains, commonly known as the Rockies, are a major mountain range in western North America. The Rocky Mountains stretch more than 3,000 miles (4,800Â km) from the northernmost part of British Columbia, in western Canada, to New Mexico, in the Southwestern United States. Within the North American Cordillera, the Rockies are somewhat distinct from the Pacific Coast Ranges and the Cascade Range and Sierra Nevada, which all lie further to the west.