Unit 41 Review Questions

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. What would you expect to find at the apex of an alluvial fan, the point where an ephemeral stream emerges from its valley?

Thicker layers with finer sediments correct incorrect

Thicker layers with coarser sediments correct incorrect

Thinner layers with finer sediments correct incorrect

Thinner layers with coarser sediments correct incorrect

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. How do stream meanders typically change over time?

They expand on their outer edges through erosion while deposition occurs on their inner edges. correct incorrect

They expand on both their outer and inner edges through erosion. correct incorrect

They slowly migrate upstream. correct incorrect

They eventually evolve in stream braids. correct incorrect

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. You look out on a river valley and see point bars, oxbow lakes, and natural levees, with a pair of terraces above the floodplain. Which of these features began forming before the others?

The point bars correct incorrect

The oxbow lakes correct incorrect

The natural levees correct incorrect

The terraces correct incorrect

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. The formation of an oxbow lake:

initially involves focuses on erosion, with deposition important at the end correct incorrect

initially focuses on deposition, with erosion important at the end correct incorrect

involves deposition processes almost exclusively correct incorrect

is most likely to occur with a braided stream correct incorrect

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. Strath terraces:

are built during periodic floods correct incorrect

are composed of material deposited by mass movements correct incorrect

occur when a stream incises its floodplain correct incorrect

necessarily involves aggradation correct incorrect

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. Both alluvial fans and river deltas:

occur at a variety of elevations and locations around the world correct incorrect

have a wide variety of shapes correct incorrect

have the largest sediments near the mouth of the stream correct incorrect

are strongly affected by erosive forces correct incorrect

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. The Mississippi Delta:

is undergoing substantial subsidence in some areas correct incorrect

has neither bottomset beds nor topset beds correct incorrect

has a classic "delta" shape correct incorrect

has most of its sediment quickly removed by wave and current action correct incorrect