Third Grade
Worksheets
Constructive Erosion: Soil
Erosion is a natural process that moves rock, sediment, and soil from one place to another. Erosion wears away rock. Erosion carries away bits of land. Flowing water can cut a gully or a canyon. Winds can blow away sand from beaches or topsoil from farm land. You might think that erosion is always destructive in nature. But in a way, erosion can be constructive, too. You might say that erosion constructs soil.
What is soil? Soil starts out as pieces of rock. All of the rocky bits that make up soil started out as much bigger rocks.
How do big rocks get smaller? As years and years pass by, the rocks slowly weather. They are broken down into smaller and smaller pieces. Rain, wind, and ice break rock into smaller bits. Temperature helps, too. When a rock gets hot from the sun, it expands, or gets bigger. When the rock gets cold, it gets smaller. Sometimes this getting bigger and smaller makes rocks break into pieces. Ice can get into small holes or cracks in rocks. When it freezes, it can break the rock apart. Ocean waves break down rocks into small pieces called sand.
