Sedimentary rock formation occurs through burial and compaction. Which phrase best describes this?

• A. Igneous crystallization
• B. Sedimentary rock formation
• C. Metamorphic change
• D. Weathering and erosion

Answer: (B)

Lithification is the process by which loose sediments become solid rock through burial and compaction. When sediments are deposited in layers, the weight of overlying material squeezes the grains closer together and expels air and water. Minerals dissolved in groundwater can then cement the grains, binding them into rock. This contrasts with igneous crystallization, which forms rocks from cooled molten material; metamorphic change, which alters existing rocks under high heat and pressure; and weathering and erosion, which break down rocks and move material rather than creating new rock. So the phrase that matches the description is sedimentary rock formation.