Which form of mechanical weathering occurs when overlying rocks are eroded, causing underlying rocks to expand and fracture in sheets parallel to the surface?

💡 Solution & Explanation

Exfoliation is a mechanical weathering process where immense confining pressure is released when overlying rock layers erode away, allowing the exposed rocks to expand and fracture in thin concentric sheets or plates parallel to the surface. Other choices like frost wedging involve the freeze-thaw cycle of water in cracks, whereas thermal expansion stems from daily temperature fluctuations. This process is frequently observed in massive intrusive igneous bodies like granite domes.