Relative dating practice
Time factors of millions and billions of years is difficult even for adults to comprehend.However, "relative" dating or time can be an easy concept for students to learn.
On a larger scale, even between continents, fossil evidence can help in correlating rock layers.Imagine that throughout your life youve taken many pictures. Certain groups of fossil animals and plants occur in the geologic record in a specific order.Rather than putting them into a photo album they are stacked up in a box. If a scientist finds one of those fossils they can then assume the age of the rock based on the age of the fossil.Scientists also use direct evidence from observations of the rock layers themselves to help determine the relative age of rock layers.Specific rock formations are indicative of a particular type of environment existing when the rock was being formed.*Earth and Space Science: Fossils provide important evidence of how life and environmental conditions have changed.The complete "Paleontology and Dinosaurs" module takes approximately four weeks to teach. " activity is a 30-minute introduction to geologic time.*Life Science: Fossils indicate that many organisms that lived long ago are extinct.Extinction of species is common; most of the species that have lived on the earth no longer exist.Therefore, the igneous intrusion may be below a layer that is older than it.The USGS has a good introduction of Relative Dating to have you practice putting historical events in the correct order.