3/12 – Today you have a test!Get out your notes and study!

DSQ #3 – What do deltas, bars, and sand dunes all have in common?

Lets Review!

• What is the difference between a u-shaped valley and a v-shaped valley?

U – Shaped is made by glaciers. V-shaped is made by rivers.

• Rill – Smallest• Gully – Next smallest• Stream – Larger• River Largest

Abrasion

• A form of erosion that results in pitted or smoothly polished rocks.

Where is chemical weathering more rapid?

• In moist, warm air

What do deltas, bars, and sand dunes have in common?

• They all are created because sediment accumulates.

What is a delta?

• A landform created when sediment accumulates in large amounts at the mouth of a river.

Mechanical Weathering

• Animals• Ice wedging (freezing and thawing)• Plant roots

• NOTICE: Sunlight DOES NOT cause weathering!

Chemical Weathering

• Acids• Oxidation (When iron is exposed to water and

oxygen)

Canyons

• Formed by streams (water)

AND

• WATER IS THE MOST IMPORTANT AGENT OF EROSION!

Rock Flour

• A fine powder left behind when GLACIERS scrape rock.

SOIL

• A mixture of organic matter, weathered rock, air, and water.

• It is affected by organisms, parent rock type, and climate.

Deflation

• WIND picks up small sediment and leaves behind larger sediment.

LOESS

• Silt that is carried by the wind then deposited

MASS MOVEMENT

• Creep – slowly moves downhill• Mudflow – sediment mixes with water• Slump – along a curved surface• Rockslide – break loose and fall