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However, paleomagnetic data show that mantle plumes can also be associated with Large Low Shear Velocity Provinces (LLSVPs) [7] [8] and do move relative to each other. [9] The current mantle plume theory is that material and energy from Earth's interior are exchanged with the surface crust in two distinct and largely independent convective flows:
Mantle plumes were first proposed by J. Tuzo Wilson in 1963 [4] [non-primary source needed] and further developed by W. Jason Morgan in 1971. A mantle plume is posited to exist where hot rock nucleates [clarification needed] at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust. [5]
Divergence of continental plates (i.e. the Atlantic Mid-Ocean ridge complex) creates magmas very near the surface of the Earth. A plume of heat from the mantle will melt rocks, creating a hot spot, which can be located at any depth in the crust. Hot spots in oceanic crust develop different magmatic plumbing systems based on plate velocities. [9]
The formation and development of plumes in the early mantle contributed to triggering the lateral movement of crust across the Earth's surface. [18] The effect of upwelling mantle plumes on the lithosphere can be seen today through local depressions around hotspots such as Hawaii. The scale of this impact is much less than that exhibited in the ...
The rest of the material is then carried upwards via chemical-induced buoyancy and contributes to the high levels of basalt found at the mid-ocean ridge. The resulting motion forms small clusters of small plumes right above the core-mantle boundary that combine to form larger plumes and then contribute to superplumes.
Hot mantle materials rising up in a plume can spread out radially beneath the tectonic plate causing regions of uplift. [13] These ascending plumes play an important role in LIP formation. When created, LIPs often have an areal extent of a few million square kilometers and volumes on the order of 1 million cubic kilometers.
RR: Reykjanes Ridge; KR: Kolbeinsey Ridge; JMMC: Jan Mayen Microcontinent; AR: Aegir Ridge; FI: Faroe Islands. Red lines: boundaries of the Caledonian orogen and associated thrusts, dashed where extrapolated into younger Atlantic Ocean. [17] Iceland is a 1 km high, 450x300 km basaltic shield on the mid-ocean ridge in the northeast Atlantic Ocean.
Mantle convection is the very slow creep of Earth's solid silicate mantle as convection currents carry heat from the interior to the planet's surface. [2] [3] Mantle convection causes tectonic plates to move around the Earth's surface. [4] The Earth's lithosphere rides atop the asthenosphere, and the two form the components of the upper mantle ...