Fourth Grade
Worksheets
Two Kinds of Weathering
The Earth's surface is always changing. Some of the changes happen fairly fast. Some changes take a very long time. Scientists believe that the processes that changed the surface of the Earth in the past are still the same today. This idea is called the principle of uniformity. They believe that these processes have been the same, or uniform, throughout time.
Weathering is one process that changes the Earth's surface. Weathering is the breaking down of the solid part of the Earth's solid surface. Large boulders are broken down into smaller rocks. Rocks are broken down into smaller and smaller pieces until they become part of the soil. Many things can cause this breaking down: wind, water, ice, plants, animals, and chemical changes. Weathering is a slow process. It is also a continuous process. There are two main types of weathering. They are mechanical and chemical weathering.
