Chemical Weathering <ul>Chemical weathering is when chemicals in rock react with either: carbon dioxide, rainwater, and oxygen. It breaks rocks down without changing its minerals. </ul>This is an example of chemical weathering.
Carbonic Acid <ul>When carbon dioxide combines with rainwater, a substance called carbon acid forms. Carbon acid can break down rocks into pieces. </ul>This may have been weathered by carbon acid.
Humus <ul>Humus is decaying or decayed plant or animal material. Humus puts carbon dioxide into the soil which could mix with rainwater. </ul>This is humus.
Physical Weathering <ul>Physical Weathering is when the rocks change shape and break down. There are many forms of physical weathering. There is: <li>Abrasion
Abrasion <ul>If wind carries sand, and the sand might get into a crack of a rock. If the wind blows, the sand flies around and over years, it will carve out magnificent shapes. This is called abrasion. </ul>This is abrasion.
Exfoliation <ul>When buried rocks, like granite, have all the soil above them weathered away, they expand. The sides are like,” Look! More space!” Then, they begin to peel off like an onion since they have expanded. </ul>Half Dome has been exfoliated.
Horizons <ul>Horizons are different layers of humus, soil, and rock. Horizons closer to the surface will have more humus than the horizons below it. </ul>