Pacific-Farallon Ridge
Encyclopedia
The Pacific–Farallon Ridge is a former mid-ocean ridge
that existed between the Pacific
and Farallon
plates in the Pacific Ocean
during the Tertiary
period. Its appearance was in a north-south direction. About 60 million years ago, it might have extended at least 10000 km (6,214 mi). Remnants of the Pacific–Farallon Ridge include the Explorer
, Gorda
, Juan de Fuca
and the East Pacific
ridges.
Mid-ocean ridge
A mid-ocean ridge is a general term for an underwater mountain system that consists of various mountain ranges , typically having a valley known as a rift running along its spine, formed by plate tectonics. This type of oceanic ridge is characteristic of what is known as an oceanic spreading...
that existed between the Pacific
Pacific Plate
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million square kilometres, it is the largest tectonic plate....
and Farallon
Farallon Plate
The Farallon Plate was an ancient oceanic plate, which began subducting under the west coast of the North American Plate— then located in modern Utah— as Pangaea broke apart during the Jurassic Period...
plates in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
during the Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
period. Its appearance was in a north-south direction. About 60 million years ago, it might have extended at least 10000 km (6,214 mi). Remnants of the Pacific–Farallon Ridge include the Explorer
Explorer Ridge
The Explorer Ridge is a mid-ocean ridge, a divergent tectonic plate boundary located about west of Vancouver Island, British Columbia, Canada. It lies at the northern extremity of the Pacific spreading axis...
, Gorda
Gorda Ridge
The Gorda Ridge is a tectonic spreading center located off the coast of Oregon and northern California north of Cape Mendocino. It runs from a triple junction with the San Andreas Fault and the Mendocino Fracture Zone northward to another transform boundary, the Blanco Fracture Zone...
, Juan de Fuca
Juan de Fuca Ridge
The Juan de Fuca Ridge is a tectonic spreading center located off the coasts of the state of Washington in the United States and the province of British Columbia in Canada. It runs northward from a transform boundary, the Blanco Fracture Zone, to a triple junction with the Nootka Fault and the...
and the East Pacific
East Pacific Rise
The East Pacific Rise is a mid-oceanic ridge, a divergent tectonic plate boundary located along the floor of the Pacific Ocean. It separates the Pacific Plate to the west from the North American Plate, the Rivera Plate, the Cocos Plate, the Nazca Plate, and the Antarctic Plate...
ridges.