Relative dating interactive activity
The Law of Superposition, which states that in an undisturbed horizontal sequence of rocks, the oldest rock layers will be on the bottom, with successively younger rocks on top of these, helps geologists correlate rock layers around the world.This also means that fossils found in the lowest levels in a sequence of layered rocks represent the oldest record of life there.The study of fossils and the exploration of what they tell scientists about past climates and environments on Earth can be an interesting study for students of all ages.Teaching about Earth's history is a challenge for all teachers.INTRODUCTION Scientists have good evidence that the earth is very old, approximately four and one-half billion years old.Scientific measurements such as radiometric dating use the natural radioactivity of certain elements found in rocks to help determine their age.If certain fossils are typically found only in a particular rock unit and are found in many places worldwide, they may be useful as index or guide fossils in determining the age of undated strata.
By correlating fossils from various parts of the world, scientists are able to give relative ages to particular strata. Relative dating tells scientists if a rock layer is "older" or "younger" than another. They could be as close as Arizona or as far away as the Gobi Desert in Mongolia! So that's where the team and I goto places with sedimentary rock.*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.