Consider the following statements related to river terraces: 1. They are surfaces marking old valley floor or floodplain levels. 2. They may be bedrock surfaces without any alluvial cover or alluvial terraces consisting of stream deposits. 3. They are basically products of deposition as they result due to vertical erosion by the stream into its own depositional floodplain. Which of the statements given above is/are correct?
- A.1 only
- B.1 and 2 only
- C.2 and 3 only
- D.1, 2 and 3
Correct answer
Explanation
The correct answer is B, 1 and 2 only. River terraces mark old valley floors and may be of bedrock or alluvium, but they are products of erosion, not deposition, so statement 3 is wrong.
A river first builds a floodplain by depositing sediment. When it later cuts down into that floodplain, the old floor is left standing above the new channel as a step-like terrace along the valley side. Some terraces are bare rock benches, while others are made of the river's own deposits. The down-cutting may follow a fall in sea level, uplift of the land, a change in the river's load or a shift in climate. Terraces at the same height on both banks are called paired terraces.
A is wrong because statement 2 is also correct. C is wrong because statement 3 is false and statement 1 is true. D is wrong because statement 3 calls terraces products of deposition, while the vertical erosion it describes makes them erosional features.
Exam tip: river terraces are erosional landforms cut into old floodplains.
Practice Questions
View allDoldrum are
1. equatorial calms
2. calm and light winds
3. roaring forties
4. variable both in position and in extent
Select the correct answer using the code given below:
- A.1, 2 and 4
- B.2 and 3 only
- C.1 and 3
- D.2, 3 and 4
Show answer
The doldrums are the equatorial belt of calm and light, variable winds, and the belt shifts with the seasons; they have nothing to do with the roaring forties.
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- C.Bhopal
- D.Kanpur
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- A.shifting cultivation.
- B.mixed farming.
- C.truck farming.
- D.plantation agriculture.
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Read the full explanation →The Tetrahedral Hypothesis of the origin of continents and ocean basin was proposed by
- A.F.B. Taylor
- B.Lowthian Green
- C.Alfred Wegener
- D.W.M. Davis
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Read the full explanation →Which one of the following statements is correct?
For the purpose of Census 2011
- A.a person aged seven and above who can both read and write with understanding in any language is treated as a literate
- B.a person aged eight and above who can both read and write with understanding in any language is treated as a literate
- C.a person aged nine and above who can both read and write with understanding in any language is treated as a literate
- D.a person aged ten and above who can both read and write with understanding in any language is treated as a literate
Show answer
In Census 2011, a person aged seven and above who could both read and write with understanding in any language was counted as literate.
Read the full explanation →