Igneous Rock • Formed when magma cools – Inside the Earth • Can be heated under pressure – Becomes metamorphic rock • Can be melted again to form new magma – Above the ground • Can be weathered and eroded – Becomes sedimentary rock
Igneous Rock Continued… • Intrusive – Large grained – Cools below the surface of the Earth • Large crystals form when magma cools very slowly • Extrusive – Fine grained – Cools close to surface or above the ground • Small crystals form when magma cools rapidly
Igneous Rock Continued… • Vesicular – describes an igneous rock that has holes due to the formation of bubbles when gas is escaping during cooling
Sedimentary Rock • Formed when sediments compact & cement into layers – Inside the Earth • Can be heated under pressure to form metamorphic rock – Above the ground • Can be weathered again to form more new sediment
Metamorphic Rock • Formed when rock changes under heat & pressure – Inside the Earth • May melt to form magma – Above the ground • May weather & erode to form sediment
Metamorphic Rock Continued… • Foliation – banding of mineral concentrations in metamorphic rocks. Has the appearance of stripes or lines in the rock.
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