Before you begin this activity, read the book chapter listed below, which is available online through Library Reserves.
Electronic course reserves, or "e-Reserves," are articles and book chapters that are available online through the University Libraries.
Following this introduction, there are several links to different sites concerning the methods scientists use to assist them in estimating the age of the Earth.
Stratigraphy and style are both used for relative dating.
Although relative dating can tell us what is older or younger, it doesn't tell us exactly how old something is.
Each original isotope, called the parent, gradually decays to form a new isotope, called the daughter.
Each isotope is identified with what is called a ‘mass number’.
When ‘parent’ uranium-238 decays, for example, it produces subatomic particles, energy and ‘daughter’ lead-206.