Lesson Plan

Layers of Time

Illustration by Brian Crosby
Grade Level:
Third Grade-Fifth Grade
Archaeology, Earth Science, Geology, Social Studies
National/State Standards:
AZ State Standards: SS03-S1C1-02, SS04-S1C1-04, SC04-S1C4-01, SS05-S1C1-05, SC05-S1C4-01.


In this activity students will learn how archaeologists use stratigraphy to determine the relative age of artifacts.


Guiding Questions: What is stratigraphy? What is the law of superposition? How can archaeologists study stratigraphy to determine the age of archaeological objects?

Lesson Objectives: Students will...

  • Explain what stratigraphy is.
  • Describe the law of superposition.
  • Understand how stratigraphy can be used to determine the age of archaeological objects.


See downloadable .pdf under the materials section.


  • Background Information
  • Layers of Time Activity and Questions
  • Layers of Time Answer Key


Students will read background information and study the stratigraphy activity example.  

By studying the stratigraphy illustration, students will complete the activity questions to determine the age of the layers and objects found in the layers.


To assess learning students will complete the questions in the Layers of Time activity.

Additional Resources

This lesson plan was developed by Brian Crosby, archaeology graduate student at Northern Arizona University.