Mantle: –upper mantle and –lower mantle Upper mantle and crust constitute Lithosphere where the rocks are in rigid form.
Lower mantle is also called Asthenosphere where the rocks are in plastic state.
The boundary between the crust and mantle is called the Moho.
The mantle: –67% of Earth's mass –Density 3.3 g/cc –depth of 70-2900 kilometers. –Consists of olivine, pyroxene and garnet –Seismic wave velocity is 8 km/sec. The boundary between the crust and mantle is called the Moho.
What is isostasy? It’s a balance or equilibrium of the earth’s crust floating on the dense mantle. Can be compared with wooden blocks floating on water. The higher the wood block appears, the deeper its root.