The Sierra Nevada Fault is an active seismic fault along the eastern edge of the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...

mountain block in

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

. It forms the eastern escarpment of the Sierra Nevada, extending roughly from just north of the Garlock Fault to the Cascade Range.

Tectonic activity

Uplift on this fault is about 0.01–0.03 mm per year. This movement, combined with the activity of the adjacent Owens Valley and Lone Pine faults, is responsible for the continuing rise of the Sierra Nevada Mountains. No large

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...

has been reported on this fault in

recorded history Recorded history or written history describes the historical events that have been recorded in a written form or other documented communication which are subsequently evaluated by historians using the historical method. For broader world hi ...

. The largest earthquake in its vicinity was the

1872 Lone Pine earthquake The 1872 Owens Valley earthquake – also known as the Lone Pine earthquake – struck on March 26 at in the Owens Valley (California, along the east side of the Sierra Nevada), with the epicenter near the town of Lone Pine. Its magnitude has ...

, which was on the adjacent Owens Valley Fault and had an estimated moment magnitude of 7.4–7.9.

History

Around 200 million years ago, the ancient oceanic

Farallon Plate The Farallon Plate was an ancient oceanic plate. It formed one of the three main plates of Panthalassa, alongside the Phoenix Plate and Izanagi Plate, which were connected by a triple junction. The Farallon Plate began subducting under the w ...

began to subduct beneath the

North American Plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacifi ...

. As the Farallon moved eastward, it was overridden by the North American, and the moisture within it was figuratively baked out of the rock before the crust melted into magma. As it began to cool, a large mass of igneous rock was created and is now visible as the

granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies und ...

domes of the

Sierra Nevada Batholith The Sierra Nevada Batholith is a large batholith which forms the core of the Sierra Nevada mountain range in California, exposed at the surface as granite. The batholith is composed of many individual masses of rock called '' plutons'', which f ...

. Batholiths are large masses of igneous rock that form deep below the surface, and they are thought to be the “roots” of

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...

-zone volcanoes. After the below-surface formation of the granite, processes such as uplift and erosion eventually expose it to the surface.

Mechanics and processes

There are several contributors to the uplift of the Sierra Nevada Batholith. Shear forces replace compression as the North American plate begins riding over with the Pacific plate. On the other side of the Sierra Nevada Range, the

Basin and Range Province The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternatin ...

is pulled apart as the force of compression increases.Kurbatova, Elena. "Geology of the Sierra Nevada Mountain Range." Geology of the Sierra Nevada Mountain Range. N.p., n.d. Web. 03 Dec. 2015. It is the Farallon Plate subsidence which is thought to be the force behind the creation of the Sierra Nevada.

References

{{California Faults Seismic faults of California