Exfoliation is common in granite, an intrusive igneous rock which is formed deep within the crust and under great pressure from the overlying materials. When granitic rocks are moved to the surface by tectonic processes, the pressure is released and the granite expands slightly, resulting in exfoliation.

Unloading is the removal of great weights of rock or ice that lie on the surface. The process releases pressure on underlying rocks and causes them to expand upward and crack at the surface. As a result, greater areas of rock are exposed to mechanical and chemical weathering.

Pressure release or unloading is a form of physical weathering seen when deeply buried rock is exhumed. Intrusive igneous rocks, such as granite, are formed deep beneath the Earth’s surface. They are under tremendous pressure because of the overlying rock material.

Rocks on a beach are worn down by abrasion as passing waves cause them to strike each other.

• Gravity causes abrasion as a rock tumbles down a mountainside or cliff.
• Moving water causes abrasion as particles in the water collide and bump against one another.
• Strong winds carrying pieces of sand can sandblast surfaces.

Erosional processes along coastlines include: (1) the direct effects of hydraulic action, wedging, and cavitation by waves; (2) abrasion (corrasion), using sand, gravel, and larger rock fragments as tools; (3) attrition of the rock particles themselves during this abrasive action; (4) salt weathering or fretting; (5) …

Abrasion – When pebbles grind along the river bank and bed in a sand-papering effect. Attrition – When rocks that the river is carrying knock against each other. They break apart to become smaller and more rounded. Solution – When the water dissolves certain types of rocks, eg limestone.