Fossils
Fossil means something dug up, a fossil was an animal that was formerly living but then got buried suddenly. Paleontologists are people who study fossils, organisms harden into fossils under the right circumstances. Fossils can occur quickly in flood like conditions.an example of a fossil is petrified wood it is fossilised by minerals replacing the tissue of the wood.
The grand canyon

Since no human witnessed the formation of the grand canyon no one can prove their theory. Today radioactive dating is used to assign relative dates to start layers in the canyons. Radioactive dating is when elements like carbon decay or lose options . If carbon has too many neutrons it will become unstable, unstable atoms will lose particles and become stable. Scientists can observe the time required for half of the unstable atoms to become stable; this is called half-life. Scientists know the present decay of an individual atom like carbon.the decay rate functions like a stopwatch ticking.
Transcontinental rock layers

There are 6 mega sequences of rock layers; all six are visible in the grand canyon. All of these layers are layered out through north america . these layers were discovered about 50 years ago.