Weathering is the breakdown and alteration of rocks and minerals at or near the Earth’s surface into products that are more in equilibrium with the conditions found in this environment. Most rocks and minerals are formed deep within the Earth’s crust where temperatures and pressures differ greatly from the surface. Because the physical and chemical nature of materials formed in the Earth’s interior are characteristically in disequilibrium with conditions occurring on the surface. Because of this disequilibrium, these materials are easily attacked, decomposed, and eroded by various chemical and physical surface processes. Weathering is the first step for a number of other geomorphic and biogeochemical processes. The products of weathering are a major source of sediments for erosion and deposition….