Which process involves breaking rock down in place by physical forces such as freeze-thaw or root growth?

• A. Physical weathering
• B. Erosion
• C. Weathering
• D. Deposition

Answer: (A)

Breaking rock in place by physical forces is physical weathering. This type of weathering mechanically breaks rock into smaller pieces without changing the minerals’ chemical makeup. Freeze-thaw cycles push water into cracks, water freezes and expands, widening those cracks; roots growing through fractures also pry rock apart. The key is that the rock is broken where it sits; erosion would move those fragments away, and deposition would be the settling of material somewhere else. Weathering includes both physical and chemical processes, but the scenario describes the mechanical breakdown in place, making physical weathering the correct concept.