Which sediment is finer than sand and commonly forms in calm water conditions?

• A. Terrigenous Sediment
• B. Silt
• C. Turbidite
• D. Well-Sorted Sediment

Answer: (B)

In sediment deposition, particle size is governed by the energy of the environment. Low-energy, calm water lets only the smallest particles settle, so finer materials accumulate there. Silt sits between sand and clay in size—smaller than sand, roughly 0.002–0.063 mm—so it forms easily in quiet conditions like lagoons, sheltered shores, or deep, calm offshore areas. That’s why silt is the sediment finer than sand that commonly forms in calm water. The other options don’t fit as well: terrigenous is a broad category of land-derived material, turbidites come from high-energy turbidity currents, and well-sorted just describes uniform grain size rather than specifically indicating a finer-than-sand sediment.