Rocks

What are rocks? Rock is a compact mass of mineral matter

Types of Rocks Metamorphic Rocks Igneous Rocks Sedimentary Rocks

Igneous rocks

Igneous Rocks What are They? Fire Rocks Formed underground by trapped, cooled magma Formed above ground when volcanoes erupt and magma cools

Types of Igneous Rocks Scoria Granite Pumice Obsidian

Igneous Rocks These are rocks that are formed by the cooling and solidification of molten rock (magma) from beneath the earth’s crust. They are normally crystalline. Lava forms igneous rock. Granite and basalt are the main examples.

Types of Sedimentary Rocks Sandstone Limestone Gypsum Conglomerate Shale

Sedimentary Rocks How They are Made Wind and water break down the earth Bits of earth settle in lakes and rivers Layers are formed and build up Pressure and time turn the layers to rock

Sedimentary rock This is a group of rocks that is formed from sediments – they Have accumulated overlong periods of time, and usually under water Have a layered structure, and are described as being stratified Often contain fossils Sandstone, limestone, chalk and coal are all examples

Metamorphic Rocks What are They? Rocks that have changed They were once igneous or sedimentary Pressure and heat changed the rocks

Types of Metamorphic Rocks Schist Gneiss

Metamorphic rock These are a type of rock which has been altered from an earlier one by heat and/or pressure. For example – marble is a metamorphic rock which was once limestone, a sedimentary rock. Metamorphic rocks are tough and resistant to erosion and are often used as building materials eg Slate

Rocks

What is weathering? What is Erosion?

Weathering is . . . Erosion is . . . Weathering is the breakdown of rocks due to the weather Erosion is the breakdown of rock due to their contact with water, ice, heat or anything which rubs against the rock