The process defined as breaking down rocks into smaller pieces without changing the rocks' compositions is **mechanical weathering**. This type of weathering physically breaks rocks into smaller fragments without altering their chemical composition.
Mechanical weathering can occur through various processes such as:
1. **Frost Wedging:** Water seeps into cracks in rocks, freezes, and expands, causing the rocks to break apart.
2. **Root Wedging:** Plant roots grow into crevices in rocks, exerting pressure and breaking the rocks apart.
3. **Abrasion:** Rocks rubbing against each other or against other materials can wear them down over time.
4. **Pressure Release:** When overlying materials are eroded away, rocks beneath the surface expand and crack due to the reduced pressure.
By understanding mechanical weathering and its different mechanisms, we can see how rocks undergo physical breakdown into smaller pieces without any change in their chemical composition.
