Correct Option
The correct option is 2 only
Explanation
River terraces are step-like landforms found on the flanks of a river valley. They represent remnants of former valley floors or floodplain levels that have been abandoned as the river incised downward due to tectonic uplift, sea-level changes, or climatic fluctuations.
Statement-wise Analysis
- Statement 1 is Incorrect: River terraces are surfaces marking old valley floor or floodplain levels. They indicate the level at which the river stream flowed in the past before vertical erosion lowered the riverbed.
- Statement 2 is Correct: River terraces are fundamentally considered products of erosion, specifically vertical erosion (downcutting). While the terrace bench may consist of alluvial deposits, the formation of the terrace as a distinct morphological feature is caused by the stream cutting into its own depositional floodplain or bedrock.
- Statement 3 is Incorrect: Paired terraces occur at the same elevation on either side of the river, typically indicating rapid vertical erosion in a symmetrical valley. Terraces that occur at different elevations on opposite sides are termed unpaired terraces, which often result from lateral shifting of the river combined with slow downcutting.
Key Takeaway
River terraces are erosional landforms representing abandoned floodplains; paired terraces exist at equal elevations on opposite banks, whereas unpaired terraces are found at unequal elevations.