The eroding of rock surfaces by other pieces of rock carried by rivers or the sea, also known as corrasion.

The eroding of rock surfaces by other pieces of rock carried by rivers or the sea, also known as corrasion.

• A. Alluvium
• B. Air Pressure
• C. River Cliff
• D. Abrasion

Answer: (D)

Abrasion is the process where rock surfaces are worn away by particles carried by water. In rivers and coastal areas, pebbles, sand, and gravel jam against the bedrock or cliff face, grinding and scratching it down. This rubbing action polishes surfaces and can create grooves, which is what corrasion describes. The other options aren’t the process: alluvium is sediment deposited by a river, not erosion; air pressure isn’t the mechanism here; a river cliff is a landform formed by erosion rather than the action itself. So the described eroding by carried rock is abrasion.

Abrasion is the process where rock surfaces are worn away by particles carried by water. In rivers and coastal areas, pebbles, sand, and gravel jam against the bedrock or cliff face, grinding and scratching it down. This rubbing action polishes surfaces and can create grooves, which is what corrasion describes. The other options aren’t the process: alluvium is sediment deposited by a river, not erosion; air pressure isn’t the mechanism here; a river cliff is a landform formed by erosion rather than the action itself. So the described eroding by carried rock is abrasion.