Matching Pairs Fossils VocabularyOnline version 3rd Grade by Sharon Ferguson 1 limestone 2 petrified wood 3 fossil fuels 4 cement 5 imprint 6 fossils 7 fossil imprint 8 fossilized preserved to become a fossil. a natural fuel such as coal or gas, formed in the geological past from the remains of living organisms. a hard sedimentary rock, composed mainly of calcium carbonate or dolomite, used as building material and in the making of cement. is a fossil in which the organic remains have been replaced by minerals in the slow process of being replaced with stone. are the remains and traces of ancient organisms. a powdery substance made with calcined lime and clay. It is mixed with water to form mortar or mixed with sand, gravel, and water to make concrete. impress or stamp (a mark or outline) on a surface. are formed from an organism moving in some way, leaving behind a trace or track. These tracks are preserved when the clay/silt dries slowly and is covered by other sediment.