Weathering and Erosion
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Transcript of Weathering and Erosion
Weathering and Erosion• Weathering and erosion are two natural
processes that work together to shape the surface of the earth.
• Weathering is the breaking down of rock into smaller particles.
• Erosion is when any kind of rock material or soil is moved to another location.
What do you think contributed to the formation of this?
Can you see evidence of weathering and erosion taking place here?
Two types of Weathering1. Mechanical weathering is when rocks are
broken in smaller pieces by a physical forceAbrasion: when rocks knock or scrape against
each other
Abrasion: mechanical weathering
Which rocks are you more likely to find on a river bed? Why?
Two types of Weathering1. Mechanical weathering is when rocks are
broken in smaller pieces by a physical forceAbrasion: when rocks knock or scrape against
each otherIce wedging: when water in cracks freezes
and causes rocks to split
Ice wedging
Two types of Weathering1. Mechanical weathering is when rocks are
broken in smaller pieces by a physical forceAbrasion: when rocks knock or scrape against
each otherIce wedging: when water in cracks freezes
and causes rocks to splitPlant action: when plant roots grow into rocks
and cause them to crack and split
Weathering by plants
Two types of Weathering1. Mechanical weathering is when rocks are
broken in smaller pieces by a physical forceAbrasion: when rocks knock or scrap against
each otherIce wedging: when water in cracks freezes
and causes rocks to splitPlant action: when plant roots grow into rocks
and cause them to crack and split2. Chemical weathering wears away rock by
chemical reaction
Two types of Weathering1. Mechanical weathering is when rocks are
broken in smaller pieces by a physical forceAbrasion: when rocks knock or scrape against
each otherIce wedging: when water in cracks freezes
and causes rocks to splitPlant action: when plant roots grow into rocks
and cause them to crack and split2. Chemical weathering wears away rock by
chemical reaction Dissolving by acid
Dissolving by acid
Remember our acid test? What was
happening to our rocks?
Stalactites
Stalagmites
Acid rain from pollution
Two types of Weathering1. Mechanical weathering is when rocks are
broken in smaller pieces by a physical forceAbrasion: when rocks knock or scrap against
each otherIce wedging: when water in cracks freezes and
causes rocks to splitPlant action: when plant roots grow into rocks
and cause them to crack and split2. Chemical weathering wears away rock by
chemical reaction Dissolving by acid Oxidation (rusting)
Chemical weathering
Oxidation
Weathering and Erosion• Weathering and erosion are two natural
processes that work together to shape the surface of the earth.
• Weathering is the breaking down of rock into smaller particles.
• Erosion is when any kind of rock material or soil is moved to another location.
Erosion(moving of rock and soil)
• What can move rock and soil from one place to another?
Erosion(moving of rock and soil)
• What can move rock and soil from one place to another?Moving water; rain runoff, rivers, oceans etc.
Erosion(moving of rock and soil)
• What can move rock and soil from one place to another?Moving water; rain runoff, rivers, oceans etc.Wind; can carry sand, dust and soil
Erosion(moving of rock and soil)
• What can move rock and soil from one place to another?Moving water; rain runoff, rivers, oceans etc.Wind; can carry sand, dust and soilIce; glaciers and icebergs
Erosion(moving of rock and soil)
• What can move rock and soil from one place to another?Moving water; rain runoff, rivers, oceans etc.Wind; can carry sand, dust and soilIce; glaciers and icebergsGravity; mudslides, landslides and gradual creep
Gravity is the underlying force of erosion
Gravity
Sudden landslide Gradual creep
Erosion(moving of rock and soil)
• What can move rock and soil from one place to another?Moving water; rain runoff, rivers, oceans etc.Wind; can carry sand, dust and soilIce; glaciers and icebergsGravity; mudslides and landslides
Gravity is the underlying force of erosion
• Deposition: when rock or soil is dropped in a new place.
Can you see evidence of weathering and erosion here?
How might this rock have formed cracks?
Describe how these
gravestones probably look different from
when they were carved? What do
you think is responsible for these changes?
Homework
• Describe 4 ways that nature can break down rocks into smaller pieces.