Erosion/Deposition 2020

The occurrence of parallel scratches on bedrock in a U-shaped valley indicates that the area has most

likely been eroded by

• a glacier

• a stream

• waves

• wind

Pieces of bedrock material that are broken from a cliff and deposited by a landslide at the base of the

cliff are best described as

• rounded and sorted

• rounded and unsorted

• angular and sorted

• angular and unsorted

A stream’s velocity decreases from 100 cm/s to 5cm/s. Which size sediment particles will still be

transported by the stream?

• pebbles, sand, silt, and clay

• silt and clay, only

• sand, silt, and clay, only

• clay, only

A landslide is an example of

• river deposition

• glacial scouring

• mass movement

• chemical weathering

The cross section below represents a portion of a meandering stream. Points X and Y represent two

positions on opposite sides of the stream.

Based on the cross section, which map of a meandering stream best shows the positions of points X

and Y?

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Which cross section best represents the valley shape where a rapidly flowing stream is cutting into the

bedrock in a mountainous area?

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The block diagram below represents a stream flowing from a mountain region.

A brief, heavy rainstorm occurs in the mountains. How will the volume of water and the rate of erosion

in the stream change shortly after the rainstorm?

• Both the volume of water and the rate of erosion will increase.

• Both the volume of water and the rate of erosion will decrease.

• The volume of water will increase and the rate of erosion will decrease.

• The volume of water will decrease and the rate of erosion will increase.

A river’s current carries sediments into the ocean. Which sediment size will most likely be deposited in

deeper water farthest from the shore?

• pebble

• Sand

• Silt

• Clay

The map below shows a meandering stream as it enters a lake. The arrow shows the direction of stream flow. Points A through D represent locations on the surface of the stream.

The greatest stream velocities are found closest to points

• A and B

• B and C

• C and D

• D and A

Base your answer to the following question on The photograph below shows a large granite boulder

that does not match the composition of the bedrock below it.

Which statement correctly explains the source of this boulder?

• This is a glacial erratic left behind during the last glacial retreat.

• Prevailing winds carried this boulder to its current location.

• A stream with a velocity of 100 cm/s deposited the boulder many years ago.

• Mass movement deposited the boulder.