The lower mantle near the core is hotter than the upper mantle near the crust.
Is most of the upper mantle made of granite.
The cooler mantle material will there fore tend to sink while the hooter material will tend to rise.
Most of the minerals in the mantle are silicates meaning they contain silica.
A glassy texture is the result of lava that has cooled very slowly.
Much of upper mantle is thought to be made of granite.
Temperatures range from approximately 200 c 392 f at the upper boundary with the crust to approximately 900 c 1 650 f at.
Granite is found in the crust primarily conditnental crust as.
Rapid cooling of magma or lava results in rocks with small interconnected mineral grains.
It is liquid rock that keeps the earth s outermost layer the crust floating and moving across the surface of our world.
The upper mantle of the earth is a very thick layer of rock inside the planet which begins just beneath the crust at about 10 km 6 2 mi under the oceans and about 35 km 22 mi under the continents and ends at the top of the lower mantle at 670 km 420 mi.