In a soil profile including clay, inorganic clay, claying gravel, and silt, what is the depth?

In a soil profile including clay, inorganic clay, claying gravel, and silt, what is the depth?

• A. 4 ft
• B. 6 ft
• C. 2 ft
• D. 8 ft

Answer: (A)

Depth is how far the soil extends from the surface down to the lowest layer described. When a profile lists layers in order from top to bottom—clay, inorganic clay, claying gravel, and silt—the bottom of that sequence marks the depth of the soil as given. Since the lowest material mentioned is silt and it ends at four feet below the surface, the depth of the soil profile is four feet. A shallower depth would stop before reaching the silt layer, while a deeper depth would require additional layers not described.

Depth is how far the soil extends from the surface down to the lowest layer described. When a profile lists layers in order from top to bottom—clay, inorganic clay, claying gravel, and silt—the bottom of that sequence marks the depth of the soil as given. Since the lowest material mentioned is silt and it ends at four feet below the surface, the depth of the soil profile is four feet. A shallower depth would stop before reaching the silt layer, while a deeper depth would require additional layers not described.