Rocks

Sedimentary Rocks

• Sedimentary rocks are formed when sediments are pressed together over a long period of time.

• Sediments include rock particles, such as mud, sand or pebbles, usually washed into rivers and eventually deposited on the riverbed or sea.

• They can also come from remains of living things, such as plants and animals

• Chemical sedimentary rocks form when water evaporates, leaving behind a solid substance.

Metamorphic Rocks

• Metamorphic rocks are formed when other types of rocks are changed by extreme heat and pressure inside the Earth.

• When igneous, sedimentary or even metamorphic rocks are heated to extreme temperatures by magma, or when placed under pressure due to rocks above them, they can change into a different type of rock.

• Metamorphic rocks are stronger than the original rocks as they are formed under great pressure and heat

• Bands can also appear, which tell us that the crystals have been squeezed together under immense pressure.

Formation of Landforms

• The gradual breaking down of rocks is called weathering.

• Rocks are gradually broken down and sculpted through both physical and chemical processes.

Weathering

• Rocks are slowly worn down into smaller pieces by weathering.

• The causes are either chemical or physical

Physical Weathering

• Physical weathering refers to the breakdown of rocks by non-living things.