The Sonomia Terrane is a geologic

crustal block Fault blocks are very large blocks of rock, sometimes hundreds of kilometres in extent, created by tectonic and localized stresses in Earth's crust. Large areas of bedrock are broken up into blocks by faults. Blocks are characterized by relat ...

known as a "

terrane In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its own ...

" whose remnants today lie in northwest

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

. The terrane acquired its name from the

Sonoma Range The Sonoma Range is a small mountain range in northwest Nevada, USA. It lies just south of the Humboldt River between Winnemucca and Golconda. It is one of the many ranges of the basin and range geologic province of the Great Basin. Sonoma Pe ...

in that region. The Sonomia Terrane is associated with the

Golconda Thrust The Golconda Thrust is a major oceanic terrane that was thrust over central and northern Nevada, North America, in possibly sometime between the Late Permian and the late Jurassic. It is considered equivalent to the Tobin thrust fault. It contai ...

, a structure named for its proximity to the town of

Golconda, Nevada Golconda is a census-designated place in southeastern Humboldt County, Nevada, United States. As of the 2010 census it had a population of 214. It is located along Interstate 80 on the Humboldt River in the northwestern part of the state. Golco ...

. The Sonoma orogeny was caused by the

accretion Accretion may refer to: Science * Accretion (astrophysics), the formation of planets and other bodies by collection of material through gravity * Accretion (meteorology), the process by which water vapor in clouds forms water droplets around nucl ...

of the Sonomia

microcontinent Continental crustal fragments, partly synonymous with microcontinents, are pieces of continents that have broken off from main continental masses to form distinct islands that are often several hundred kilometers from their place of origin. Caus ...

onto western North America during the mid-

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

References

Geology of Nevada Terranes {{US-geology-stub