Which statement accurately describes the texture of coastal dune deposits?

• A. Fine to coarse sands
• B. Silty clays and organic matter
• C. Predominantly gravel and boulders
• D. Volcanic ash layers

Answer: (A)

Coastal dune deposits are formed by wind-driven sand, which yields a texture made up mainly of sand-sized particles. That means the soil is composed of fine to coarse sands, with little to no clay or organic matter typical of marshes or peat soils. The sand texture is a hallmark of dunes, helping explain their quick drainage and limited water retention. The other textures describe different environments: silty clays and organic matter point to peat or finer, organic-rich soils; gravel and boulders indicate a much coarser, rocky material; volcanic ash layers are specific to volcanic settings and not inherent to typical coastal dunes. So the statement that coastal dune deposits are fine to coarse sands best captures their texture.