Chapter 6: Weathering and Soils . Introduction: Weathering—The Breakdown of Rock. At the Earth’s surface, rocks are exposed to the effects of weathering: the chemical alteration and mechanical breakdown of rock, when exposed to air, moisture, and organic matter.
Soils are one of the most important natural resources. Soils support the plants that are the basic source of our nourishment and provide food for domesticated animals. Soils store organic matter, thereby influencing how much carbon is cycled in the atmosphere as carbon dioxide, and they also trap pollutants.