Weathering and erosion are the processes that sculpt and mold the surface features of the Earth. There is a constant conflict between forces that cut down the surface and forces that raise the surface. Weathering is the breakdown of material by air, water, plants, and, animals. Erosion is the movement or transport of that weathered material. Physical weathering is physical disintegration of a rock into smaller fragments, each with the same properties as the original. Physical weathering occurs mainly by temperature and pressure changes. Chemical weathering is the process by which the internal structure of a mineral is altered by the addition or removal of elements. Change in phase (mineral type) and composition are due to the action of chemical agents. Chemical weathering is dependent on availabl her by chemical means more rapidly than large particles due to an increase of surface area. Deposition is the process of dropping or depositing sediment in a new location.
Weathering and erosion
Rocks are often formed inside the Earth at high pressure and temperatures. At the Earth's surface, when rocks are exposed, the conditions are quite different. It is this change that causes rocks and minerals to break up. Physical weathering breaks down the rocks into smaller particles, such as grand or grits. In chemical weathering,the minerals that form the rocks are dissolved by the action of water, together with oxygen and carbon dioxide in the air. Once the rocks have been broken down by weathering, the bits are transported elsewhere by ice, wind, running water, or gravity. This is called erosion.
