Rocks are made from many grains being joined together. As you know, rocks come in many shapes and sizes.
The three main types of rock are: sedimentary, igneous and metamorphic.
The rocks in the Earth are always changing due to the changes in the Earth such as erosion. This is known as the rock cycle, which takes place over millions of years.
We will cover the rock cycle, which links to all 3 types of rock. Below is the diagram of the rock cycle which shows sedimentary, igneous and metamorphic rock being weathered into sediment.
There are many different cycles within the rock cycle, so it is not just one big straightforward cycle, there are many loops within it.
This process is described in the process of forming sedimentary rock.
As you can see below, erosion consists of weathering and transportation.
1. Large rocks break up into smaller pieces (sediment) – This process is weathering
2. The pieces of broken rock get transported when by wind, water, etc. – This process is transportation
3. The pieces then settle in layers at the bottom of the ocean – This is called deposition.
4. The weights sediments above and the water squashes the sediment together – This process is known as compaction.
5. Sedimentary rock is formed as the sediment layers stick together – This process is called cementation.
Rocks may not stay in the form of sedimentary rock forever, as rocks are part of a cycle.
6. When sedimentary rock is under the conditions of high and pressure, it can form metamorphic rock.
7. When metamorphic rock melts, it turns into magma.
8. Magma can crystallise and turn into intrusive igneous rock. However, it could also become lava, which will crystallise and turn into extrusive igneous rock.
Sedimentary rock, metamorphic rock and igneous rock can all slowly uplift to the surface to undergo weathering.