The answer is oxidation or chemical weathering. There are three main types of weathering, which includes, mechanical weathering, biological and chemical weathering. Mechanical weathering is caused by wind, sand rain, thawing, freezing, and other forces that can physically alter the rock. Biological weathering is caused by the activities of plants and animals as they grow, nests and burrow. Chemical weathering is caused by chemical reactions rather than by mechanical means.
