the process that changes the size and shape of rock
weathering and erosion
The process that changes the size and shape of rocks is called weathering and erosion.
1. Weathering:
Weathering is the process by which rocks are broken down into smaller pieces. There are three main types of weathering:
a) Physical Weathering: This involves the breaking of rocks into smaller pieces without any chemical change. Physical weathering can occur due to various factors like temperature changes (freeze-thaw cycles), wind, water, or even the growth of plants and animals.
b) Chemical Weathering: This process involves the breakdown of rocks due to chemical reactions. Examples of chemical weathering include the reaction of rocks with water, acids, or oxygen in the air. Over time, chemical weathering can dissolve minerals and change the composition of rocks.
c) Biological Weathering: This type of weathering occurs due to the actions of living organisms like plants and animals. For example, the roots of plants can grow into cracks in rocks, exerting pressure and causing them to break apart.
2. Erosion:
Erosion is the process by which weathered rock materials are transported and removed from their original location. Erosion typically occurs through the action of natural forces such as water, wind, ice, or gravity.
a) Water Erosion: Running water, such as rivers and streams, can carry away sediment and rocks. The force of the water can wear down and shape rocks over time.
b) Wind Erosion: Wind can transport small particles of sand, dust, and other materials, causing rocks to be worn away and shaped by abrasive action.
c) Glacial Erosion: Glaciers are huge masses of ice that flow slowly over the land. They can carry rocks and sediments, and as they move, they can grind the rocks underneath, changing their shape.
d) Gravity Erosion: Gravity can cause rocks to fall or slide downhill, which can lead to the reshaping of rocks over time.
So, the combination of weathering, which breaks down rocks into smaller pieces, and erosion, which transports and removes these broken pieces, leads to changes in the size and shape of rocks.