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
Closed Basin Project end from the Rio Grande watershed. It contains the towns of Center, Hooper, Moffat, Mosca and Saguache and the Great Sand Dunes National Park and Preserve. Streams that flow into the basin include irrigation diversions from the Rio Grande, the Carnero, La Garita, and Saguache creeks from the west, San Luis Creek from the north, and the North Crestone and Sand creeks from the east. The water spreads over the floor of the valley and either sinks into the underground aquifer or evaporates. The lowest part of the basin extends from the San Luis lakes north to the Blanca Wildlife