Asthenosphere forms the upper mantel and Mesosphere form the lower part of the mantel. The temperature of the asthenosphere is normally about 1300 to 3000 degrees C. While the mesosphere has <u>7000 degrees Fahrenheit which 3879 degrees celsius.
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Being in the lower part this material is found at a depth of 400 to 1800 miles below the surface of the earth. Being larger it takes around 70% of the earth mantle. And having the pressure of 1.3 million times that of the upper surface. Evidence can be seen from the volcanic eruptions.
The lower mantle is composed of Pyrolytic and Chondritic matter. And asthenosphere is made up of semi-solid molten matter all types of isostatic adjustment take place in this zone of influence. Compose of heavy metals and elements like iron and magnesium contains the base of oceanic crust.
A possible cause was a meteorite hit the earth. it caused many organisms to become extinct because it blocked out the Sun so plants couldn't grow and herbivores couldn't eat the plants and carnivores couldn't eat herbivores.
