The Forces of Weathering
Water is an important force that greatly effects weathering, but it is not the only force. Other forces include the atmosphere, and even plant and animal life.
The atmosphere is comprised of many different types of gases. These gases are able to penetrate into the openings of rocks. Plant roots, microscopic animals and plants, and digging animals also help to break down rocks. To better understand the different forces that cause weathering, geologists separate them into three categories. These categories are mechanical, chemical, and biotic.