Compare and Contrast Earth Layers Layer Location Crust The top Layer Description Temperature Density Composition Parts of Layer The least dense layer Continental Crust: (part that we walk on) Made of granite Less dense Oceanic Crust: (under water) Made of basalt More dense Mantle The middle Layer More dense than the crust Upper Mantle: Mixture of solid and molten rock Lithosphere (tectonic Plates) Lower Mantle: Mostly molten rock Asthenosphere ( how tectonic plates move) Core The inside layer The most dense layer Outer Core: liquid iron and nickel Where scientists think the Earth’s magnetic field comes from Inner Core: Solid iron