Chapter 28, Problem 6RAT

Sand dunes form as wind

(a) disperses sand.

(b) blows sand from the back to the front of the dune.

(c) blows sand from the front to the back of the dune.

(d) interrupts the normal sequence of deposition.

To determine

The correct option for the statement “Sand dunes form as wind.”

Answer to Problem 6RAT

The correct option for the statement ’Sand dunes form as wind” is option (c).

Explanation of Solution

A sand dune can be a hill or ridge of sand that can lie in a certain location. These are formed when the wind moves sand from the front of the dune to the back. Wind transported and deposits sediment, such as sand grains. When the speed of wind carrying sand grains is obstructed by an obstacle, such as a rock or a bunch of vegetation, then the speed of wind drops. Due to this, the sand grains settle down where the wind is blocked. When more and more sand gets to settle down, then the mound grows into a dune. This dune is called sand dune.

Conclusion:

Therefore, the correct option for the statement “Sand dunes form as wind” is option (c).