Major geological features of California

One of the best known sites in California is the Sierra Nevada Mountain range. This mountain range stretches 400 miles from north to south. In the Triassic Period an island ark crashed into the continent of North America. This created a set of mountains. At roughly the same time a subduction zone formed in roughly the same place formed plumes under ground which 0pushed the mountain range up forming the Sierra Nevada batholith.

Another mountain is Mt. Shasta.

 This volcano is formed by subduction. The Pacific Plate subducted and formed this volcano. Eruptions happen usually every 800 to 600 years.