3_Rocks - created from Mind Map

Seite 1

how they're made

weathering

sedimentary

metamorphic

igneous

sedimentary rock is layers of sediment, they compact,over time they form a solid rock

metamorphic rock is sedimentary rock put under heat and pressure they then form a solid rock.

molten rock cools slowly for large crystals and quickly for small crystals

chemical

physical

biological

acid rain; when fossil fuels such as coal and natural gas are burned, carbon dioxide and sulphur dioxide escape into the air. These dissolve in the water in the clouds and make rainwater more acidic than normal. Acid rain makes chemical weathering happen quickly

temperature changes; heat makes rocks expand then it contracts when its cooled. If this happens a lot the rock with crack.

wind, rain and waves; the wind blows tiny grains of sand against a rock which wears away the rock.

freeze-thaw; what expands slightly when it freezes into ice. if water gets into the cracks in a rock then freezes it expands and makes the crack bigger.

animals and plants can wear away rocks. For example burrowing animals such as rabbits can burrow into a crack, making it bigger and spitting the rock.

people wear away rocks by walking. Overtime paths in the countryside become damaged.

plant roots can grow in cracks. As they grow bigger, the roots push open the cracks and make wider and deeper.