ROCKS THAT REVEAL THE PAST

Tells that layered, or sedimentary, rocks often contain fossils: the remains of animals and plants that were alive when the rocks were formed. Fossils enable scientists to reconstruct the life of the past. The sedimentary rocks in which fossils are found help scientists to learn about the sequence in which living things appeared on earth. The layered rocks of the Grand Canyon provide us with fossil evidence of a billion years of earth history.