The process through which wood becomes lithified is called:

• A. Metamorphism
• B. Diagenesis
• C. Lithification
• D. Fossilization

Answer: (B)

Wood becomes lithified through diagenesis, the set of near-surface chemical, physical, and biological changes that turn organic remains and loose sediments into rock. In petrified wood, mineral-rich fluids infiltrate the wood and precipitate minerals (like silica), effectively replacing the organic material and preserving structure while turning it into rock. This is distinct from metamorphism, which requires higher temperatures and pressures and would alter the material into a different rock type, and from lithification in a broader sense, which describes cementation and compaction of sediments rather than the mineral replacement of organic material. Fossilization is a general term for preservation, but diagenesis specifically accounts for the mineralization process that lithifies wood.