Physical Weathering Processes

Physical weathering of rocks happens on a small scale that can be easily overlooked. Weathering is the process that slowly decompose rocks into small particles.

There are many types of physical weathering in nature, but the most notable weathering processes include exfoliation, freeze-thaw cycles, abrasion, root expansion, and wet-dry cycles.

Physical or mechanical weathering processes depend on some applied forces. The applied forces could be:

• Gravitational forces such as over burden pressure, load and shearing stress;
• Expansion forces due to temperature changes, crystal growth or animal activity;
• Water pressures controlled by wetting and drying cycles.

Many of these forces are applied both at the surface and within different earth materials leading to rock fracture. Most of the physical weathering processes are caused by thermal expansion and pressure release.

1. Unloading and Expansion
2. Temperature Chances and Expansion
3. Freezing, Thawing and Frost Wedding
4. Salt Weathering