Weathering refers to the group of physical, chemical, and biological processes that change the physical and chemical state of rocks and soils at and near the surface of the earth. Weathering is primarily a result of climatic forces. Because the effects of climate occur at the earth's surface, the intensity of weathering decreases with depth, with most of the effects exhibited within the first meter of the surface. The most important climatic force is water, as it moves in and around rocks and soil.

Physical weathering is the disintegration of rock into smaller pieces by mechanical forces concentrated along rock fractures. Abrasion of rocks occurs when wind or water carry particles that wear away rocks. Physical weathering due to frost is referred to as frost shattering or frost wedging. Because water expands when it freezes, it can break rocks apart from the inside when it seeps into cracks...