Geology of the Pacific Ocean Geology of the Pacific Ocean The Pacific Ocean evolved in the Mesozoic from the Panthalassic Ocean, which had formed when Rodinia rifted apart around 750 Ma. The first ocean floor which is part of the current Pacific Plate began 160 Ma to the west of the central Pacific and subsequently developed into the largest oceanic plate on Earth. The tectonic plates continue to move today. The slowest spreading ridge is the Gakkel Ridge on the Arctic Ocean floor, which spreads at less than , while the fastest, the East Pacific Rise near Easter Island, has a spreading rate of over
Geology of the Pacific Ocean as the Aleutian Arc off Alaska and the Kermadec-Tonga Subduction Zone north of New Zealand. As a result of the collision of the Nazca Plate and the South American Plate, the Andes Mountains emerged in western South America, close to the Peru–Chile Trench. Many large fracture zones aligned in an east-west direction, occur in the floor of the northeastern Pacific. The Pacific is a broad ocean basin (unlike the narrow Atlantic Ocean) and extends over a width of between New Guinea and Peru. The andesite line, a zone of intense volcanic and seismic activity, is a major regional distinction in