Question

Consider the following statements regarding river valleys:

1. The Narmada and Tapti rivers both flow in rift valleys.

2. Rivers in rift valleys usually have steep banks and limited meandering.

3. Such valleys are commonly formed by fluvial erosion.

• A. 1 & 2 only
• B. 2 & 3 only
• C. 1 & 3 only
• D. All of the above

Answer 1

Answer:

A. 1 & 2 only

• Correct Answer: Option A) 1 & 2 only

• The Narmada and Tapti rivers both flow in rift valleys: True

• Both the Narmada and Tapti rivers in central India flow through rift valleys formed by tectonic activities. These are fault-guided valleys created by the sinking of land between parallel faults, not by the river's erosional activity.

• Rivers in rift valleys usually have steep banks and limited meandering: True

• Rift valleys have steep sides due to their tectonic origin. Rivers flowing through such valleys typically have steep banks and follow a relatively straight course dictated by the fault lines, limiting their ability to meander freely.

• Such valleys are commonly formed by fluvial erosion: False

• This is incorrect. Rift valleys are formed primarily by tectonic forces (faulting) where land between two parallel faults sinks down, creating a graben structure. They are not formed by the erosional action of rivers (fluvial erosion). Normal river valleys, in contrast, are formed by fluvial erosion over time.

• Therefore, only statements 1 and 2 are correct, making Option A the right answer.