Rocks and how they are formed

Rocks are something that is all around us. They were used from making medieval weapons to modern offices and skyscrapers. They also come in different shapes, sizes and colour, and they are also many types of rock. There is slate, gravel, graphite, stone, limestone, sandstone, chalk, and many more. They are also formed in different ways.

A rock is a solid thing, and there are three main different types of rock. There are Metamorphic rocks, Igneous rocks and Sedimentary rocks. Metamorphic rocks are formed because the rocks are under a lot of pressure, and this encourages heat build up, so eventually they ‘morph’ into a Metamorphic rock. Igneous rocks are formed because when a volcano erupts, the magma hardens into an Igneous rock. Finally, a Sedimentary rock is formed because all of the dirt and mud from the bottom of the river/sea (this dirt is called sediment) comes up and some of it gets washed up on the shore, and this hardens to form a Sedimentary rock.

Weather may wear away rocks, such as pieces of a Basalt Cliff, and when the rock pieces fall down, they are eroding, and when they are wearing away, they are weathering. Many people get these two terms confused.

Strong rivers and streams can move rocks. This is called transport.

Sometimes two rocks on the same river/stream may collide, and this is how they get round and wear away.