The Salton Trough is an active tectonic

pull-apart basin In geology, a basin is a region where subsidence generates accommodation space for the deposition of sediments. A pull-apart basin is a structural basin where two overlapping (en echelon) strike-slip faults or a fault bend creates an area of cru ...

, or graben. It lies within the

Imperial Imperial is that which relates to an empire, emperor, or imperialism. Imperial or The Imperial may also refer to: Places United States * Imperial, California * Imperial, Missouri * Imperial, Nebraska * Imperial, Pennsylvania * Imperial, Texas ...

, Riverside, and

San Diego San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United States ...

counties of southeastern

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 ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

and extends south of the

Mexico–United States border The Mexico–United States border ( es, frontera Estados Unidos–México) is an international border separating Mexico and the United States, extending from the Pacific Ocean in the west to the Gulf of Mexico in the east. The border trav ...

into the state of

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

. The northwestern end of the trough starts at the San Gorgonio Pass in Riverside County, and extends southeast to the Gulf of California. Major geographical features located in the trough include the

Coachella Valley , map_image = Wpdms shdrlfi020l coachella valley.jpg , map_caption = Coachella Valley , location = California, United States , coordinates = , width = , boundaries = Salton Sea (southeast), Santa Rosa Mountains (southwest), San Jacin ...

, the

Salton Sea The Salton Sea is a shallow, landlocked, highly saline body of water in Riverside and Imperial counties at the southern end of the U.S. state of California. It lies on the San Andreas Fault within the Salton Trough that stretches to the Gu ...

, and the Imperial Valley, in the United States, and the western side of the Mexicali Valley, and the Colorado River Delta in Mexico. The Salton Trough is a result of crustal stretching and

sinking Sinking may refer to: * Sinking of a ship; see shipwrecking * Being submerged * ''Sinking'' (album), a 1996 studio album by The Aloof * Sinking (behavior), the act of pouring out champagne in the sink * Sinking (metalworking), a metalworking t ...

caused by the combined actions of the

San Andreas Fault The San Andreas Fault is a continental transform fault that extends roughly through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip (horizontal) ...

and the

East Pacific Rise The East Pacific Rise is a mid-ocean rise (termed an oceanic rise and not a mid-ocean ridge due to its higher rate of spreading that results in less elevation increase and more regular terrain), a divergent tectonic plate boundary located alon ...

, particularly the Gulf of California Rift Zone (GCRZ), the northernmost portion of the East Pacific Rise. The GCRZ and the San Andreas Fault both terminate near the south end of the Salton Sea, in an area called the Brawley Seismic Zone. The Brawley seismic zone is an active spreading center that connects the San Andreas Fault system with the Imperial Fault Zone to the south. The Salton Trough is also referred to as a sedimentary basin because the basin has filled with sedimentary deposits as quickly as the basin has been sinking. In some areas, the sediment is more than deep. Sources of the sediment are the mountainous areas that surround the trough, and the

Colorado River The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid watershed that encompasses parts of seven U.S. s ...

, which in the past fed

Lake Cahuilla Lake Cahuilla ( ; also known as Lake LeConte and Blake Sea) was a prehistoric lake in California and northern Mexico. Located in the Coachella and Imperial valleys, it covered surface areas of to a height of above sea level during the Holocen ...

, a large inland freshwater lake, that disappeared after the Colorado River changed course to the Gulf of California.

Facts about the Salton Trough

*At below sea level, the Salton Sink is the topographic low area within the Salton Trough, and is the second-lowest point, after

Death Valley Death Valley is a desert valley in Eastern California, in the northern Mojave Desert, bordering the Great Basin Desert. During summer, it is the hottest place on Earth. Death Valley's Badwater Basin is the point of lowest elevation in North Am ...

, on the North American continent. At the

, which fills the lowest part of the Salton Sink, is the lowest lake in North America. *The Salton Trough is commonly subject to migrating earthquake swarms. *The Salton Buttes, located within the Salton Sea, are rhyolite

lava dome In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruption ...

s within the basin which were active 10,300 (± 1000) years BP. *Within the field of

Physical Geography Physical geography (also known as physiography) is one of the three main branches of geography. Physical geography is the branch of natural science which deals with the processes and patterns in the natural environment such as the atmosphere, ...

the Salton Trough is classified as a distinct section of 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 ...

within the Intermontane Plateaus division of the American Landmass. * The Niland Geyser is one of dozens of mud pots and mud volcanoes in the Salton Trough, but is the only one in the world known to have moved significantly, affecting the

Union Pacific Railroad The Union Pacific Railroad , legally Union Pacific Railroad Company and often called simply Union Pacific, is a freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Pac ...

California State Route 111 State Route 111 (SR 111) is a state highway in the U.S. state of California. It is the main north-south route and retail corridor through the Coachella Valley, a part of the Colorado Desert in the southeastern corner of the state and a famous reso ...

, and other infrastructure since 2018.

References

Pull-apart basins Colorado Desert Geologic provinces of California Geology of Imperial County, California Geology of Riverside County, California Geology of San Diego County, California Geological depressions in the United States Physiographic sections Physiographic regions of the United States *Trough Geography of Baja California {{US-geology-stub