Chemical breakdown of rocks by addition or subtraction of elements, usually resulting in new mineralogy. Biological breakdown of rocks by living organisms, either physically or chemically. Fractures parallel to the ground are caused by the removal of pressure from overlying rock. Changes in temperature result in thermal expansion .
Hot objects expand Cold objects contract Expansion occurs at the mineral scale .
Dissolution Equation Formation of carbonic acid occurs naturally. Carbonic acid reacts with calcite to breakdown the mineral into ions. Hydrolysis Hydrolysis is the process by which aluminum rich felsic minerals breakdown to form clay. Process occurs in the upper few meters of the Earth s surface. Important for providing potassium nutrients to plants.