Weathering is a slow, continuous process that affects all substances exposed to the atmosphere. There are two major types of weathering, mechanical and chemical. Mechanical weathering causes the parent rock to break into smaller fragments without changing the chemical makeup of the rock. Chemical weathering is the process of changing the makeup of the parent rock through chemical reactions. Most chemical weathering is caused by water.
Water can dissolve most minerals that hold rocks together.
Some rocks dissolve very easily in water and are called soluble. Oxidation is the process in which oxygen chemically combines with another substance. The result of oxidation is the formation of an entirely different substance. When carbon dioxide dissolves in water, a weak acid called carbonic acid is formed. This acid can dissolve some types of minerals.