Salton Buttes

The Salton Buttes are a group of five small lava domes in the lower Coachella Valley, in Imperial County, California. They are the only active volcanoes in Southern California, and are associated with the East Pacific Rise. The Salton Buttes include: Mullet Island, Obsidian Butte, Red Island, and Rock Hill.

The Salton Buttes domes are on the southeast shoreline of the Salton Sea and are associated with the Salton Sea geothermal field within the Salton Trough (Salton Sink). They are on the north margin of the Brawley seismic zone.

Red Island is composed of two domes separated by some 200 m of Quaternary gravels. They consist of rhyolite and volcanic activity may have occurred in 6450 BC. A 2012 study, however indicates the buttes may have last erupted more recently, between 940 and 0 BC. Within the geothermal area older age buried domes have been encountered in drilling operations.

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