The Salton Sea would not exist without the unique geology of southern California, USA and northwestern Mexico and water from the Colorado River
Over millions of years, the tectonic movement in the region, in a process called crustal spreading, caused a section of northwestern Central America, just south of the Salton Sea, to separate from the main land mass and created what is now known as the California Baja Peninsula. As the rift between the peninsula and mainland widened, the area between them subsided, filled with water from the Pacific Ocean, and formed what is now known as the Gulf of California / Sea of Cortez.
It is a commonly publicized theory that silt deposits from the Colorado River cut off the northern part of the gulf / sea from the rest of the water and created the predecessor to the Salton Sea, a much larger lake known as Lake Cahuilla. But that is not completely accurate.
Animation Depicting Creation of the Salton Sea without consideration of Tectonic Plate Movement Contribution
This animation portrays the Colorado River Delta silt deposits cutting off the northern section of the gulf / sea. It fails to demonstrate the contributions of tectonic plate movement to the creation of the sunken land that Lake Cahuilla and the Salton Sea would eventually occupy. It may lead viewers to believe lakes in this region were solely created by silt deposits, which is not correct.