Which environment is NOT typical for sedimentary rock formation?

• A. Riverbeds
• B. Oceans
• C. Deserts
• D. Glaciers

Answer: (D)

Sedimentary rocks form when particles settle out of a transporting medium and later become solid rock through lithification. Riverbeds and oceans provide calm or periodically quiet environments where sediments settle out and accumulate in distinct layers, leading to common layered rocks like sandstone, shale, and limestone. Deserts accumulate wind-blown sand and dust that also settles in beds and later lithifies, giving sandstone and related rocks. Glaciers, however, transport and grind material and deposit it as till or outwash, which is usually poorly sorted and lacks the well‑defined, continuous layering typical of most sedimentary rocks. Because of this difference in how sediments are deposited, glaciers are not a typical setting for forming sedimentary rocks.