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Thermal or compositional fluid-dynamical plumes produced in that way were presented as models for the much larger postulated mantle plumes. Based on these experiments, mantle plumes are now postulated to comprise two parts: a long thin conduit connecting the top of the plume to its base, and a bulbous head that expands in size as the plume rises.
The active rift model sees rupture driven by hotspot or mantle plume activity. Upwellings of hot mantle, known as mantle plumes, originate deep in Earth and rise to heat and thin the lithosphere. Heated lithosphere thins, weakens, rises, and finally rifts, Enhanced melting following continental breakup is very important in VPMs, creating ...
An example of plume locations suggested by one recent group. [38] Figure from Foulger (2010). [3] Many different localities have been suggested to be underlain by mantle plumes, and scientists cannot agree on a definitive list. Some scientists suggest that several tens of plumes exist, [38] whereas others suggest that there are none. [3]
A mantle plume rises from the core to the surface. P-T-t paths play an important role in the development of plume tectonics, supported by anticlockwise P-T paths. [11] [49] Plume tectonics are considered to be the dominant process forming the Archean crust with evidence from the study of the Archean cratonic blocks in the North China Craton.
The high pressure in the lower mantle has been shown to induce a spin transition of iron-bearing bridgmanite and ferropericlase, [5] which may affect both mantle plume dynamics [6] [7] and lower mantle chemistry. [5] The upper boundary is defined by the sharp increase in seismic wave velocities and density at a depth of 660 kilometers (410 mi). [8]
Second, flow of hot mantle material encounters the base of the thin lithosphere and often results in melting and a new phase of volcanism. Delamination may thus account for some volcanic regions that have been attributed to mantle plumes in the past. [6]
Plume tectonics is a geoscientific theory that finds its roots in the mantle doming concept which was especially popular during the 1930s and initially did not accept major plate movements and continental drifting. It has survived from the 1970s until today in various forms and presentations.
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 ...