Erosion and Deposition

A river carries dirt and mud out of the land it runs through

• Mechanical Weathering
• Chemical Weathering
• Erosion
• Deposition

Which of the following statements is not true?

• Water causes more erosion on slopes without plants
• Water flows from higher to lower ground
• Faster water erodes more sediment
• As water slows, smaller particles are deposited first

You are a planetary geologist investigating images of a planet elsewhere in the galaxy. You see gentle U-shaped valleys carved in the planet’s surface. Based on Earth’s geology what would you suspect caused these valleys?

• Stream erosion
• Glacial erosion
• Stream deposition
• Marine erosion

How would you expect the sizes of sediments deposited on a mountain to compare to those deposited downriver?

• Larger
• Smaller
• The same
• It is impossible to predict

When a stream or river starts to slow down, it:

• Picks up more sediment
• Erodes more rapidly
• Deposits fine sediments, but continues carrying larger rocks
• Deposits larger rocks, but continues carrying finer sediment

The steeper the slope, the ________ the stream.

• Slower
• Broader
• Faster
• Curvier

Streams with steep gradients have a(n) _____ velocity than those with gentle gradients.

• Greater
• Lesser
• Average
• None of these

Madison creates the model shown of a stream bed. She wants to demonstrate how natural processes can change the surface of Earth through deposition and erosion. She pours water on her model and makes observations. In which situation will more deposition than erosion occur in Madison's stream bed model?

• More deposition will occur if the slope of the stream increases.

• More deposition will occur if sediment in the stream decreases.

• More deposition will occur if sediment in the stream increases.

• More deposition will occur if the speed of the stream water decreases.

How does erosion compare to physical weathering?

• Both break down materials.

• Erosion breaks down materials, and weathering carries them from place to place.

• Weathering breaks down materials, and erosion carries them from place to place.

• Both move materials from place to place.

Which of the following is organic material that results from the decay of plant and animal remains?

• humus

• gravel

• R horizon

• clay