Gilbert and Ellice Islands atolls and coral islands in the western Pacific Ocean that are recognised as part of the Micronesia subregion of Oceania. The Gilbert Islands are the main part of what is now Republic of Kiribati ("Kiribati" is the Gilbertese rendition of "Gilberts") The atolls and islands of the Gilbert Islands are arranged in an approximate north-to-south line. In a geographical sense, the equator serves as the dividing line between the northern Gilbert Islands and the southern Gilbert Islands. The Ellice Islands are south of the Gilbert Islands. The Ellice Islands comprises three reef islands and six true atolls spread out between
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