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A mantle plume beneath the Paraná may feed both the Fernando de Noronha, the Martin Vaz and some continental volcanic fields. [28] Seismic tomography suggests that this mantle plume is actually the remnant of the plume associated with the Tristan hotspot. [36] Edge-driven convection may be occurring at the margin of Brazil. This would be ...
It was later postulated that hotspots are fed by streams of hot mantle rising from the Earth's core–mantle boundary in a structure called a mantle plume. [6] Whether or not such mantle plumes exist has been the subject of a major controversy in Earth science, [4] [7] but seismic images consistent with evolving theory now exist. [8]
Nevertheless, some scientists dispute the plume model, arguing instead that volcanic activity associated with the Marquesas hotspot and others in the southern Pacific results from shallow tectonic processes. In this interpretation, volcanism in the Marquesas is a consequence of intraplate stresses caused primarily by reorganisations of plate ...
There is an ongoing discussion about whether the hotspot is caused by a deep mantle plume or originates at a much shallower depth. [3] Recently, seismic tomography studies have found seismic wave speed anomalies under Iceland, consistent with a hot conduit 100 km (62 mi) across that extends to the lower mantle.
Mantle plumes were first proposed by J. Tuzo Wilson in 1963 [3] [4] and further developed by W. Jason Morgan in 1971 and 1972. [4] A mantle plume is posited to exist where super-heated material forms at the core-mantle boundary and rises through the Earth's mantle.
The deep mantle plume hypothesis on Canary hotspot formation proposes how the current-day Canary islands rested above a province of tholeiitic magma during the Triassic Period. The province, known as the Central Atlantic Magmatic Province (CAMP), became active and extended over 10 million km 2 , developing into what scientists call today the ...
Many hotspots occur near or on tectonic plate boundaries while others (eg. Hawaii) are far from the nearest plate edge. It is generally believed that a mantle plume, a column of anomalously hot material rising up from the core-mantle boundary, reaches the bottom of the crust (lithosphere) and spreads out, melting and mixing with some crustal rock.
A possible model for the formation of the volcanic Samoa island chain is explained by the Samoa hotspot situated at the east end of the Samoa Islands. In theory, the Samoa hotspot is a result of the Pacific Tectonic Plate moving over a 'fixed' deep and narrow mantle plume spewing up through the Earth's crust. The Samoa islands generally lie in ...