Changing Earth’s Surface – Max learned that physical and chemical weathering processes can change objects on Earth’s surface over time. Physical weathering breaks rocks into small pieces without changing the composition or chemical makeup of the rock. Some physical weathering processes are caused by glaciers, wind, water, and the activities of organisms. Then we explored the effects of physical weathering from forest fires, ice wedging, abrasion, plants, and animals. Next he discovered the effects of chemical weathering which changes the materials that are part of a rock into new materials. Some examples are acid rain and oxidation which both cause chemical weathering of rocks. Max learned that the Earth is constantly changing and being reshaped by constructive and destructive processes. Constructive processes such as the cooling of lava build up features on Earth’s surface but destructive processes such as strong hurricanes tear down features on Earth’s surface. The process by which glaciers, wind, or water carry sediments to new locations is called erosion. Then he learned that the rate of erosion depends on the type of rock, for example, sandstone rocks break into large pieces but shale rocks break into small pieces. Next Max learned that deposition is the laying down or settling of eroded material.
Assignment: View examples of physical and chemical weathering by water and wind then take a quiz.