General Facts
Canyon Country sits atop rock that has been uplifted, folded, and eroded over the last few million years. Most of the hills are made up of rock from the 23 - 30 million year old Miocene Mint Canyon Formation. It was probably uplifted during the latter part of the Coast Ranges Orogeny about 1.8 million years ago. The rest of Canyon Country rests on alluvial fill and terrace deposits from the last few thousand years. Parts of the hills in the Canyon Country area are composed of the Mio-Pliocene Towsley Formation and the Pliocene Castaic Formation. These are mostly marine in origin.
Oil is not found in the Soledad Basin, but is found in the Ventura Basin. The boundary between the two basins is the San Gabriel Fault. This seep, shown above, is just south of the fault in the Ventura Basin. Many fossils have been found out here. South of Highway 14, the Towsley and Castaic Formations outcrop offering many fossil finds. Everything from shells to whale bone have been found in the hills around here.
Rivers and Drainage
The Santa Clara River is where all the streams drain to in the Canyon Country area. Mint Canyon Creek has its confluence with the Santa Clara River near Solemint Junction. That creek, while dry most of the year, drains a large portion of the mountains to the north. The Santa Clara River generally runs from east to west through the valley. In Canyon Country, it runs in Soledad Canyon and follows Soledad Canyon Road. Only a few miles have manmade levees, making this river the last remaining wild river in Los Angeles County. Shown below, the Santa Clara River runs by the main part of Canyon Country. Bridge in background is Sierra Highway.
Santa Clara River during a flood in February 1998. Taken from the Sierra Highway bridge
looking towards State Highway 14.
Faults and Folds
Most of the folds are aligned north to south. They were formed when the mountains uplifted. Some of these folds have small thrust faults which are inactive. Some are visible in a road cut near the intersection of Soledad Canyon Road and Sand Canyon Road. Some folding, especially towards the eastern end of Canyon Country have caused the tilted strata to slide, some of these are visible just east of Sand Canyon Road on the west facing slopes north of Soledad Canyon Road. These are known as dip-slope slides. Other larger landslides are to be found in the vicinity of Antelope Valley Freeway (SR- 14) near Golden Valley Road. There, three major slides exist. One, the Freeway Earthflow, causes the Antelope Valley Freeway (SR-14) to become bumpy between Cedar Valley Way and Golden Valley Road.
Description of the Mint Canyon Formation