HKDSE Geography/M1/The Earth's Layers

left|400px The various layers of Earth are summed up below: Layer (by chemical composition) Layer (by state) Maximum depth Crust (sial/sima) (1) Solid lithosphere (4) 30km Mantle (Fe and Al) (2) 100km Plastic asthenosphere (5) 640km Solid lower mantle 2800km Core (Fe and Ni) (3) Liquid outer core (6) 4600km Solid inner core (7) 6370km Crust The crust is a solid layer on the earth's surface. It includes continental and oceanic crusts. Continental Oceanic Thickness Thicker Thinner Density Lighter Denser and heavier Composition Sial - silica and aluminium Sima - silica and magnesium Geology Mainly granitic Mainly basaltic Remarks Includes continents and continental shelves Mantle It is denser, made of aluminium and iron, and divided into three parts. Upper mantle Lower mantle Rigid mantle Asthenopshere State Solid Liquid Solid Made of Rocks Magma Rocks Core It is rich in iron and nickel. The outer core is a molten liquid. The inner core is a high-pressure solid.