Which rock type forms from deposited material that becomes cemented over time?

Which rock type forms from deposited material that becomes cemented over time?

• A. Igneous rock
• B. Metamorphic rock
• C. Gneiss
• D. Sedimentary rock

Answer: (D)

Sedimentary rocks form when loose material settles out of water or air, accumulates in layers, and then becomes solid through lithification. The key parts are deposition and cementation: grains are buried and pressed together, while minerals dissolved in groundwater precipitate and bind the grains, turning the sediment into rock. This process distinguishes them from igneous rocks, which crystallize from molten material, and from metamorphic rocks, which are transformed by heat and pressure. Examples like sandstone and limestone illustrate how cemented grains or precipitated minerals create a solid rock from deposited material.

Sedimentary rocks form when loose material settles out of water or air, accumulates in layers, and then becomes solid through lithification. The key parts are deposition and cementation: grains are buried and pressed together, while minerals dissolved in groundwater precipitate and bind the grains, turning the sediment into rock. This process distinguishes them from igneous rocks, which crystallize from molten material, and from metamorphic rocks, which are transformed by heat and pressure. Examples like sandstone and limestone illustrate how cemented grains or precipitated minerals create a solid rock from deposited material.