Physical Geology concepts.pdf
Formation of Earth
-Early temperatures; melted iron/nickel (2,647oF -2795oF)
-Separation into an Inner Core / Outer Core / Mantle / Crust
-Releases of gases forming primitive atmosphere
Crust – (low density rock) Both ‘Continental’ (light;granitic) & ‘Oceanic’ (dark;basaltic)
-Part of the ‘Lithosphere’.
Mantle – (higher density rock; Dark colored, Dense, also called “Peridotite”)
-‘Upper Mantle’; 70-660 kilometers deep, Lithosphere & Asthenosphere
-‘Lower Mantle’; 660-2900 kilometers deep, Solid, High Strength
Core – (high density material)
-‘Outer Core’; Iron & Nickel “LIQUID”, earth’s magnetic field
-‘Inner Core’; ‘Solid’ Iron & Nickel
Lithosphere - Consists of the crust and upper mantle; relatively cool and rigid shell that is 100
km thick on average.
Asthenosphere - Has a thin upper layer that experiences melting and is therefore weaker. This
upper layer allows the asthenosphere to remain separate from the overlying lithosphere.