Mechanical Weathering

Mechanical (or physical) weathering is the process by which physical forces break down rock, minerals and soil into finer particles. This article treats mechanical weathering as being separate from chemical weathering, even though both types of alteration occur concurrently in nature. Following Yatsu (1988), the processes of mechanical (or physical) weathering are classified according to the kind of stresses established in geological materials. The pedological context is stressed.

Mechanical weathering due to phase changes

Frost weathering and salt weathering are considered to be caused by phase changes.

Frost weathering

This is also known as congelifraction, gelifraction, frost wedging, frost riving, frost shattering and frost splitting, all of which imply the forcing apart of materials, commonly rock, by expansion of water upon freezing in pore spaces, cracks or other gaps in the solid (Washburn, 1979, p. 73). It is common in the high latitudes and at high altitudes, where sub‐zero...