Question 47

Deposition by wind is responsible for the formation of the sand dune pictured above.

Sand dunes are primarily formed through the process of deposition, where wind transports and deposits sand particles in specific locations, creating the characteristic shapes of dunes.

A) Deposition by wind

This option is correct as sand dunes are formed when wind carries sand particles and deposits them when the wind speed decreases, leading to the accumulation of sand and the formation of dune structures.

B) Chemical weathering

Chemical weathering involves the breakdown of rocks and minerals through chemical reactions, typically involving water and atmospheric gases. This process does not directly contribute to the formation of sand dunes, making this option incorrect.

C) Physical weathering

Physical weathering refers to the mechanical breakdown of rocks into smaller particles without changing their chemical composition, often due to temperature changes or freeze-thaw cycles. While it may contribute to the creation of sand, it does not specifically explain the formation of sand dunes.

D) Deposition by flowing water

Deposition by flowing water involves the sedimentation of materials carried by rivers or streams. While this process can create landforms such as riverbanks or deltas, it is not responsible for the formation of sand dunes, which are primarily shaped by wind action.

Conclusion

Deposition by wind is the definitive process responsible for the formation of sand dunes, as it directly involves the transport and accumulation of sand particles. The other options, including chemical weathering, physical weathering, and deposition by flowing water, do not accurately describe the mechanisms that lead to the creation of sand dunes. Thus, option A is the only correct choice.