Shaping the Surface: Weathering, Erosion & Soil
Weathering, erosion, and soil study the processes that break down rocks, transport sediments, and lead to soil formation, driving landscape changes over time. Weathering disintegrates rocks physically or chemically, erosion moves the resulting sediments via wind or water, and these processes contribute to soil formation, which supports ecosystems and reshapes Earth’s surface, from river valleys to coastal cliffs.
Components of Weathering, Erosion & Soil
Weathering, erosion, and soil are defined by their processes and outcomes in shaping Earth’s surface. Here’s the breakdown:
- Weathering: The breakdown of rocks into smaller pieces through physical or chemical processes.
- Erosion: The transportation of weathered material by agents like water, wind, or ice.
- Soil Formation: The creation of soil through weathering, organic matter addition, and biological activity.
- Landscape Changes: The reshaping of Earth’s surface due to weathering, erosion, and sediment deposition.
Lists of Weathering, Erosion & Soil Components with Examples
Weathering Examples
- Physical: Frost action splits a rock as water freezes and expands in its cracks.
- Chemical: Acid rain dissolves limestone, forming caves over time.
- Physical: Wind abrades a desert rock, smoothing its surface.
Erosion Examples
- Water erosion: A river carries sediment, carving the Grand Canyon over millions of years.
- Wind erosion: Sand dunes shift as wind blows across a desert.
- Glacial erosion: A glacier drags rocks, forming U-shaped valleys in the Alps.
Soil Formation Examples
- Weathered granite mixes with organic matter to form sandy soil in a forest.
- Basalt breaks down with humus, creating fertile volcanic soil in Hawaii.
- Clay soil forms from chemically weathered shale in a wetland.
Landscape Changes Examples
- A river delta forms where sediment deposits at the Mississippi River’s mouth.
- Coastal erosion shapes cliffs along the Pacific Coast as waves remove sediment.
- Wind erosion creates arches in Utah’s deserts by removing softer material.