The rock cycle and weathering

In a nutshell

There are three types of rock on Earth: sedimentary, metamorphic and igneous rock, which are recycled in the rock cycle. Weathering, heat and pressure are important conditions required for the rock cycle.

Weathering

Rock on the Earth's surface is broken down in a process known as weathering. There are three types of weathering: biological, physical and chemical weathering. Once a rock has been broken down, the smaller bits of rock can be transported away

Weathering type	Examples
Physical	Abrasion (scraping), caused by wind and water.
Chemical	Carbonation, caused by the reaction of rocks with carbonic acid.
Biological	Root growth and microorganisms can break down rocks.

Rock cycle - key steps

The rock cycle shows how rocks transition between sedimentary, metamorphic and igneous rocks.

PROCEDURE

1.	Molten rock or magma (A) can cool down to form igneous rock (B).
2.	Weathering breaks rock down into small particles called sediment(C).
3.	Sediment is transported by rivers and deposited at sea, forming layers of rock. Compaction (squashing) and cementation (gluing) of sediment forms sedimentary rock (D)
4.	Pressure and heat underground converts sedimentary rock into metamorphic rock (E).
5.	Melting of rock to form molten rock (magma)- back to step 1 and the cycle continues.

Science; Earth and atmosphere; KS3 Year 7; The rock cycle and weathering