In a way this field, called geochronology, is some of the purest detective work earth scientists do.

Teaching relative age dating
This 5-12-grade activity introduces students to the idea of sequencing information in overlapping data sets and the Principle of Superposition, which is a core concept in relative dating. Offers history of age dating, stratigraphic principles, rock correlation, fossil correlations, radiometric dating, and the geologic time scale. Short discussion of radioactive dating and stratigraphic principles.
Radiometric Dating and the Geologic Time Scale, The Talk Origins Archive. Provides brief overview of (1) relative dating and stratigraphic methods, (2) absolute dating and radiometric dating, including a table with parent to daughter isotopes and half lives of those isotopes commonly used in radiometric dating, (3) paleomagnetics and (4) geologic time. Includes tables of common radioactive parent isotopes and their stable daughter products, and half lives of common radioactive isotopes.
This group is dedicated to providing information about the scientific method as it concerns the idea of evolution in the Creation/Evolution debate.
The site provides background information about stratigraphic principles and relative time, biostratigraphy (using fossils for relative dating), and radiometric dating.
Teaching about Earth's history is a challenge for all teachers.
Time factors of millions and billions of years is difficult even for adults to comprehend.
Determining the Age of Rocks and Fossils, University of California, Berkeley.
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.
Once students begin to grasp "relative" dating, they can extend their knowledge of geologic time by exploring radiometric dating and developing a timeline of Earth's history.
This activity was selected for the On the Cutting Edge Exemplary Teaching Collection Resources in this top level collection a) must have scored Exemplary or Very Good in all five review categories, and must also rate as “Exemplary” in at least three of the five categories.
Once they are able to manipulate the cards into the correct sequence, they are asked to do a similar sequencing activity using fossil pictures printed on "rock layer" cards.