Fossils are typically preserved in which type of rock?

• A. Sedimentary
• B. Igneous
• C. Metamorphic
• D. Glassy basalt

Answer: (A)

Fossils are preserved in rocks formed from accumulated sediments that settle in layers at the Earth’s surface or in bodies of water. When organisms die, their remains can be quickly buried by mud, sand, or silt. Over time, these layers become compacted and cemented into sedimentary rock, and the shapes or imprints of the organisms can be preserved as fossils within the rock.

Igneous rocks come from molten material that cools, and metamorphic rocks form under heat and pressure; both processes can destroy or modify fossils, so fossils are rarely found in them. Glassy basalt, for example, is an igneous rock formed from rapid cooling of lava and would not preserve fossils.

Therefore, sedimentary rock is the typical rock type that preserves fossils.