Weathering
Oh no! I'm breaking up...
That's right, it doesn't look good - I'm weathering away fast!
All rocks on the Earth's surface weather - though some weather faster than others. Three different forces work together to break up rocks into smaller pieces.
- Physical weathering - cycles of hot and cold temperatures make rocks expand and contract, and rain may freeze and expand in cracks in the rock. These processes eventually lead to rocks cracking and breaking up.
- Chemical weathering - different chemicals can dissolve rock, helping to break it up; even water can dissolve some rocks. Polluted 'acid rain' causes chemical weathering.
- Biological weathering - tree roots can force themselves into small cracks in rocks and eventually break the rocks apart.
