The Rock Cycle

Crust Mantle Outer Core Inner Core The Structure of the Earth

Sedimentary rocks Sandstone Conglomerate Limestone

Sedimentary rocks How sedimentary rocks are formed: 1) Weathering 2) Transportation 4) Burial 3) Deposition

Metamorphic rocks Slate Marble Quartzite

Metamorphic rocks Metamorphic rocks are formed by the combined effect of heat and pressure on other rocks: Pressure from rocks above… …and heat from magma nearby

Igneous rocks Granite Pumice Obsidian

Igneous rocks Igneous rocks are formed when lava or magma cools down and solidifies If the lava or magma cools QUICKLY it has SMALL crystals If the lava or magma cools SLOWLY it has BIG crystals

Summary Sedimentary, igneous or metamorphic? How they were formed Appearance (e.g. sandstone, limestone, chalk) Small pieces of sediment were stuck together by salt and pressure from rocks above Usually soft, can contain fossils, easily eroded (e.g. basalt, granite) Liquid rock (magma or lava) cooled down and turned back into a solid Contain crystals, very hard, never contain fossils (e.g. marble, slate) Other rocks were acted on by heat and pressure over a long time Sometimes have tiny crystals, no fossils, always hard and sometimes arranged in layers

The Rock Cycle