47. Which process is responsible for the formation of the sand dune pictured above?
Answer: A
Deposition by wind
The formation of the sand dune is primarily due to the process of deposition by wind, where sand particles are transported and accumulated to create the dune structure.
A) Deposition by wind
This option is correct as it describes the mechanism by which sand dunes are formed. Wind carries loose sand particles across the landscape, and when the wind's velocity decreases, these particles settle and accumulate, resulting in the formation of dunes.
B) Chemical weathering
This option is incorrect because chemical weathering involves the breakdown of rocks and minerals through chemical reactions, which does not contribute to the formation of sand dunes. Sand dunes require physical movement and accumulation of sand rather than chemical alteration.
C) Physical weathering
While physical weathering does contribute to the breakdown of rocks, it does not directly lead to the formation of sand dunes. Sand dunes form specifically through the transportation and deposition of sand by wind, not merely from the physical breakdown of materials.
D) Deposition by flowing water
This option is also incorrect, as it refers to the deposition process associated with rivers and streams, which leads to different landforms such as riverbanks or deltas. Sand dunes are specifically formed by wind-driven processes, not by flowing water.
Conclusion
Deposition by wind is the definitive process responsible for the formation of sand dunes, as it involves the transportation and accumulation of sand particles. Other processes such as chemical weathering, physical weathering, and deposition by flowing water do not contribute to the specific formation of dunes, highlighting the unique role of wind in shaping these landscapes.