Weathering
What does “weathering” mean?
The breaking down of rocks into smaller pieces.
What moves weathered rock and soil?
Water, wind, ice, or gravity.
What is a canyon?
A deep valley formed by river erosion.
What happens in a landslide?
Rocks and soil quickly slide downhill.
Picture of rocks with cracks and roots growing through them. What is happening here?
Weathering – roots are breaking the rocks apart.
“The roots are growing into cracks in the rock. As the roots expand, they push the rock apart and break it into smaller pieces. This is a type of weathering because the rock is being broken down without being moved.”
Give one example of weathering.
Water freezing in cracks, roots breaking rocks, or acid rain dissolving rock.
How does water cause erosion?
It carries away particles and reshapes land.
What landform forms from deposition?
A delta or sand dune
How can roots break apart rock?
They grow into cracks and force rocks apart.
This is picture of a river carrying soil. What process is happening?
Erosion – water is moving sediment from one place to another.
Erosion is when water, wind, or ice wears away soil, rocks, or other materials from one place and moves them to another. In this case, the river is carrying soil downstream, which is a classic example of water erosion.
How can plants cause weathering?
Roots grow into cracks and break rocks apart
What is wind erosion?
Wind blows loose sand and soil from one place to another.
Describe how a delta forms.
Sediments build up at a river’s mouth as water slows.
What happens when ice freezes in cracks of rock?
It expands, breaking the rock — frost wedging.
Show water depositing sand at a river’s mouth. What process is this?
Deposition – sediment is being dropped as water slows.
Deposition happens when a river slows down and drops the sediment (like sand, silt, or rocks) it has been carrying. At a river’s mouth—where the river meets a lake, sea, or ocean—the water loses energy, so it can no longer carry the sediment, and it settles, forming features like deltas or sandbars.
So, erosion is taking material away, and deposition is dropping it somewhere else.
What’s the difference between weathering and erosion?
Weathering breaks rocks apart; erosion moves them.
What causes glaciers to erode land?
Ice scrapes and drags rock as glaciers move.
How do rivers shape land?
They carve valleys and move soil downstream.
What’s one way erosion changes cliffs near the ocean?
Waves wear away rock to form sea caves or arches.
Show a diagram of a mountain slowly wearing down. What processes are happening?
Weathering and erosion – rocks break down and move over time.
Weathering – The mountain’s rocks are breaking down into smaller pieces because of wind, water, ice, temperature changes, or plant roots. This doesn’t move the material yet; it just loosens it.
Erosion – The broken-down rock and soil are then carried away by wind, water, or ice to other places.
So over time, the mountain wears down and its material is transported elsewhere.
Describe chemical vs. physical weathering.
Chemical changes the rock’s makeup; physical breaks it down without changing composition.
Explain how humans can prevent erosion.
Plant trees, build barriers, or use mulch to protect soil.
Name 3 landforms caused by erosion.
Canyon, valley, arch, or sea cliff.
Why do mountains get smaller over time?
Weathering and erosion wear them down
Sequence it: rocks break → rocks move → rocks settle. Draw arrows showing the correct order.
Weathering → Erosion → Deposition – arrows show movement and change.