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MechanicalWeathering

ChemicalWeathering

Rates of Weathering

SoilSoil

Conservation

Frost action where water seeps into cracks, freezes, and breaks

rock during cold weather

Ice Wedging

The part of plants that gets into cracks, grows, expands, and

breaks rock

Roots

The process when rocks and sand rub, scratch, and wear away other

rocks

Abrasion

Abrasion caused by rocks falling on other rocks

Gravity

True or False: Mechanical weathering changes the rock’s

composition

False

True or False: Over time, water can dissolve the minerals of

rocks.

True

A type of chemical weathering caused by polluted precipitation.

Acid Rain

These living things produce acids that break down rock over time.

Lichens

Chemical weathering that occurs when air reacts with iron in rocks

to create rust.

Oxidation

True or False: Wind abrasion is a form of chemical weathering.

False

True or False: Water can be both a mechanical & chemical

weathering agent.

True

The rate (or time it takes) for rocks to weather depends on

climate, elevation, and _______________ (what the rock

is made of).

Composition

Rocks in __________ climates will weather away faster because

they are exposed to more ice, wind, and precipitation.

Colder/cooler/higher

_____________ Weathering happens faster in warm, humid

climates

Chemical

True or False: The less rock that is exposed, the more it will

weather away.

False

Devil’s Tower (where the softer part of the volcano weathered away but left the harder rock

behind) is an example of __________ weathering.

Differential

The source (or beginning) of the soil is the __________ rock

parent

The dark soil found in Horizon A full of nutrients from decaying

plants and animals

Humus

This is found in Horizon R (bottom layer) and has not been

weathered at all

Bedrock

___________ occurs in Horizon E when water drains nutrients

down into this layer

Leaching

This type of soil sediment has the smallest grain size and water will

NOT move through it easily (Sand, Clay, or Silt)

Clay

True or False: Desert soil is best for growing crops

False

A conservation technique where old harvested plants are left to

lay on top of the soil

No-till farming

Planting rows of crops across the slope of a hill to hold create less

soil erosion

Contour Plowing

Planting crops in different fields each year so that nutrients have

time to be replenished

Crop Rotation

Why is soil worth protecting?

We rely on soil to live!