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The transition zone is located between the upper mantle and the lower mantle between a depth of 410 km (250 mi) and 670 km (420 mi).. This is thought to occur as a result of the rearrangement of grains in olivine to form a denser crystal structure as a result of the increase in pressure with increasing depth. [6]
The transition zone is the part of Earth's mantle that is located between the lower and the upper mantle, most strictly between the seismic-discontinuity depths of about 410 to 660 kilometres (250 to 410 mi), but more broadly defined as the zone encompassing those discontinuities, i.e., between about 300 and 850 kilometres (190 and 530 mi) depth. [1]
Gradually through the upper mantle, pyroxenes become less stable and transform into majoritic garnet. [11] At the top of the transition zone, olivine undergoes isochemical phase transitions to wadsleyite and ringwoodite. Unlike nominally anhydrous olivine, these high-pressure olivine polymorphs have a large capacity to store water in their ...
Xenoliths (lower crust and upper mantle rock brought to the surface by volcanic eruptions) and seismic-reflection data showed that, away from continental cratons, the transition between crust and mantle is marked by basaltic intrusions and may be up to 20 km thick. The Moho may lie well below the crust-mantle boundary and care must be used in ...
After 60 years of trying, geologists finally pried rocks from Earth's upper mantle. That's huge for so many reasons.
Transition zone may refer to: Transition zone (Earth), a part of the Earth’s mantle located between the lower mantle and the upper mantle; Transition zone, the region between the near and far fields of a transmitting antenna; Transition zone (TZ), a glandular region of the prostate—see Prostate#Zones; Zone of transition, a zone in urban ...
The mantle is divided into upper and lower mantle [21] separated by a transition zone. [22] The lowest part of the mantle next to the core-mantle boundary is known as the D″ (D-double-prime) layer. [23] The pressure at the bottom of the mantle is ≈140 GPa (1.4 Matm). [24]
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 ...