Weathering
What Happens Before Erosion
What is Weathering?
Weathering is one of the forces that shapes the earth. The most basic definition is that it breaks up materials for erosion to carry away. This process is often confused with erosion. They work together, but erosion and weathering are different.
Mechanical Weathering
Mechanical weathering is the physical breaking up of material into smaller pieces. One common cause of mechanical weathering is an ice wedge. When water settles into the cracks of a rock, it will freeze when the temperature reaches 36 degrees. When water freezes, it expands and forces the rock apart.
Chemical Weathering
There are three types of chemical weathering. Below are definitions from KidsGeo.
Oxidation takes place when oxygen combines with other elements in rocks to form new types of rock. These new substances are usually much softer, and thus easier for other forces to break apart.
Hydrolysis occurs when water combines with the substances in rocks to form new types of substances, which are softer than the original rock types. This allows other forces, such as mechanical weathering, to more easily break them apart.
Carbonation takes place when carbon dioxide reacts with certain types of rocks forming a solution that can easily be carried away by water.
Mechanical Weathering
An ice wedge slowly broke this rock apart.
Chemical Weathering
This granite grave marker was once in the shape of a lamb. Chemical weathering has made it difficult to recognize the original lamb sculpture.
Ice or Frost Wedging
This diagram shows how an ice wedge works.