Magellan Rise is an oceanic plateau in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

, which covers a surface area of . There is another geological structure with the same name west from the

Marshall Islands The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Intern ...

. The Magellan Rise has been called a

large igneous province A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including intrusive (sills, dikes) and extrusive (lava flows, tephra deposits), arising when magma travels through the crust towards the surface. The formation ...

by Coffin and Endholm 2001 and was emplaced 145 million or 135-128 million years ago, possibly as a consequence of intense volcanism at a former

triple junction A triple junction is the point where the boundaries of three tectonic plates meet. At the triple junction each of the three boundaries will be one of three types – a ridge (R), trench (T) or transform fault (F) – and triple junctions can ...

. Alternatively, the Rise was formed by a

mantle plume A mantle plume is a proposed mechanism of convection within the Earth's mantle, hypothesized to explain anomalous volcanism. Because the plume head partially melts on reaching shallow depths, a plume is often invoked as the cause of volcanic hot ...

linked to the deep "JASON superplume". Candidate mantle plumes are the

Easter hotspot The Easter hotspot is a volcanic hotspot located in the southeastern Pacific Ocean. The hotspot created the Sala y Gómez Ridge which includes Easter Island, Salas y Gómez Island and the Pukao Seamount which is at the ridge's young western ed ...

and the Foundation hotspot. The volume of rocks in the Magellan Rise is about -. It apparently developed first on the

Phoenix Plate The Phoenix Plate (also known as the Aluk Plate or Drake Plate) was a tectonic plate that existed during the early Paleozoic through late Cenozoic time. It formed a triple junction with the Izanagi and Farallon plates in the Panthalassa Ocean as ...

before being transferred onto the Pacific Plate 125 million years ago. The Magellan Rise never rose to shallow depths at least since the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

, and the Rise is covered by

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sa ...

s of Tithonian/

Berriasian In the geological timescale, the Berriasian is an age/stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago ...

to Quaternary age.

Notes

References

Sources

* * {{Ocean-stub Underwater ridges of the Pacific Ocean Plateaus of the Pacific Ocean