Which feature is a line of small waterfalls and rapids on rivers?

• A. Delta
• B. Estuary
• C. Fall line
• D. Tributary

Answer: (C)

Think about what a river does as it flows from higher ground toward the sea. A line of small waterfalls and rapids along a river is called a fall line. It forms where the water drops from higher, harder rock to lower land, so the current rushes over the drop and creates rapids. In Virginia, the Fall Line separates the Piedmont from the Coastal Plain and helped shape where towns grew because ships couldn’t navigate past the rapids. Other terms describe different features: a delta is built up sediment at a river’s mouth; an estuary is where fresh and saltwater mix at the river’s mouth; a tributary is a smaller river that flows into a larger one.