Download Types of Mechanical Weathering:

Weathering and Erosion Notes
Weathering: Breaking down of rock or soil
Mechanical: physically breaking it down
Chemical: chemically breaking it down
Types of Mechanical Weathering:
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Plants growing through rocks and breaking them (trees through sidewalks)
Rocks growing crystals can split rocks
Rapid cooling can cause rocks to weaken and split
Rapid heat (like a campfire or forest fire) can cause rocks to expand and break
Animals burrowing in rocks
When rocks freeze, the water expands and causes rocks to break
Water and the sediments it contains flowing through rock
Rain pelting rocks
Windstorms
Sandstorms
****Most mechanical weathering happens in cold and wet climates due to water freezing in rocks and
splitting them apart.
Types of Chemical Weathering:
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Weak acids can be formed in water and cause chemical weathering
Carbonic acid is produced when CO2 reacts with water and can weather rocks
Some chemicals can cause rusting reactions in rocks
Acid Rain
Animal Waste
Pollution
****Since most chemical weathering occurs where there is lots of rain due to weak acids forming in water,
most chemical weathering occurs in warm and wet climates where there is lots of rain.
The following can indicate that a chemical change took place, although this evidence is not conclusive:
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Change of color (for example, silver to reddish-brown when iron rusts)
Change in temperature or energy, such as the production (exothermic) or loss (endothermic) of heat
Change of form (for example, burning paper)
Light, heat, or sound is given off
Formation of gases, often appearing as bubbles
Formation of precipitate (insoluble particles)
The decomposition of organic matter (for example, rotting food)
Erosion: Moving of sediments produced by weathering
Glaciers: A slow moving river of ice that flows downhill carried forward by its huge weight.
How glaciers form: When snow remains in one location long enough, it transforms into ice.
How glaciers cause erosion: The rocks dragged along underneath it gouge deep into the ground
creating U-shaped valleys with steep sides and flat bottoms. Glaciers can also melt and then re-freeze
causing rocks to break apart.