1. Frost Wedging:
- Water seeps into cracks in rocks.
- When the water freezes, it expands, putting pressure on the rock.
- Repeated freezing and thawing cycles widen the cracks, eventually breaking the rock apart.
2. Abrasion:
- Rocks and minerals are rubbed against each other by wind, water, or ice.
- This grinding action wears them down, creating smaller particles.
- Think of sandblasting, but with nature doing the work!
3. Exfoliation:
- Rocks that have formed deep underground are exposed to the surface.
- The pressure from the overlying rock is released, causing the rock to expand and peel away in layers, like an onion.
4. Thermal Expansion and Contraction:
- Rocks are exposed to extreme temperature changes, like hot days and cold nights.
- The different minerals in the rock expand and contract at different rates.
- This stress can cause cracks to form and eventually break the rock.
5. Root Wedging:
- Tree roots grow into cracks in rocks.
- As the roots grow larger, they put pressure on the rock, eventually breaking it apart.
6. Salt Wedging:
- Saltwater evaporates, leaving salt crystals behind in rock cracks.
- The crystals grow larger and put pressure on the rock, widening the cracks.
Important Note: Physical weathering doesn't change the chemical makeup of the rocks and minerals, only their size and shape.
