Manihiki Plateau

The Manihiki Plateau extends from 3°S to 6°S and 159°W to 169°W covering and has an estimated volume of with a crustal thickness of . Several of the Cook Islands are located on the southern part: Pukapuka, Nassau, Suwarrow, Rakahanga, and Manihiki. The Tokelau Basin borders it to the west, the Samoan Basin to the south, the Penrhyn Basin to the east, and the Central Pacific Basin to the north. It reaches up to below sea level, several kilometres shallower than the surrounding basins. The plateau can be divided into three regions. The south-eastern High Plateau is the shallowest and flattest; its basement is covered by up to a kilometre of pelagic sedimentary rock. The Western Plateaus, north-west of the High Plateau, are a series of ridges and seamounts. The North Plateau is small and almost separated from the rest of the Manihiki Plateau. The High Plateau is the largest part of Manihiki covering above 4000 m. The second largest part is the Western Plateaus covering above 5000 m and reaching below sea level. The smallest part, the North Plateau, covers above 4500 m and reaches . These plateaus are separated by failed rifts. ==Tectonic evolution==

The Manihiki Plateau was originally described as a subsided microcontinent in 1966, but has been known to be made of oceanic crust since DSDP drillings were made in the 1970s. The formation of the plateau is related to the intense volcanism of the Early Cretaceous and mid-ocean ridge jumps. A hotspot and several mantle sources were involved in the formation of the Manihiki large igneous province (LIP). The ages of multiple different samples lie in the range 126 to 116 million years ago. Other Cretaceous LIPs in the Pacific, except Ontong Java and Hikurangi, include the Hess, Shatsky and Magellan rises. ==See also==