West Coast Tectonic Evolution—20 Million Years Ago [2 of 3]

As the mid-ocean ridge separating the Farallon and Pacific Plates entered the subduction zone, the Farallon Plate separated into the Juan de Fuca and Cocos Plates. A transform plate boundary developed where the Pacific Plate was in contact with the North American Plate and the volcanism ceased in central California. Farther east, the continent began to rift apart in the Basin and Range Province.

plate tectonics geology geologic resources division west coast tectonic evolution million years pacific plates farallon plate transform plate boundary north american plate cocos plates mid ocean ridge farallon subduction zone range province national parks gallery california

2019

National Parks Gallery

https://npgallery.nps.gov/

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