Relative dating worksheet geology
Throughout the history of life, different organisms have appeared, flourished and become extinct.
Many of these organisms have left their remains as fossils in sedimentary rocks.
To determine the relative age of different rocks, geologists start with the assumption that unless something has happened, in a sequence of sedimentary rock layers, the newer rock layers will be on top of older ones. This rule is common sense, but it serves as a powerful reference point.
Geologists draw on it and other basic principles ( to determine the relative ages of rocks or features such as faults.
In a way this field, called geochronology, is some of the purest detective work earth scientists do.
There are two basic approaches: relative age dating, and absolute age dating.
The idea of radioactive decay and half lives, a type of absolute dating, is shown through an activity using M&M's candy and graph paper. Sequencing Time, University of California, Berkeley. This 5-12-grade activity lets students place parts of their own life story into a time line so that they can better understand how geologic time is reconstructed by scientists.
This 9-12-grade activity introduces students to age dating with exercises using relative and absolute dating. Links to various activities and lesson plans concerning relative and absolute dating. Content information about absolute and relative dating methods used by the U. Relative dating is used to arrange geological events, and the rocks they leave behind, in a sequence.The method of reading the order is called stratigraphy (layers of rock are called strata).Geologists have studied the order in which fossils appeared and disappeared through time and rocks. Fossils can help to match rocks of the same age, even when you find those rocks a long way apart.This matching process is called correlation, which has been an important process in constructing geological timescales.