Backbone State Park Limestone

This video shows the extensive exposed limestone features at Backbone State Park, which were formed by lime sediments that were deposited when Iowa was covered by a shallow, tropical sea about 430 million years ago.

Possible Guiding, Compelling and/or Anchoring Questions

• How did Backbone State Park get so many of these strange limestone rocks?
• Why does Backbone have so much exposed limestone and other places don’t?

Classroom Suggestions

Students could

• Compare and contrast Backbone limestone to prominent geological features in their area.
• Identify and map where similar features exist in Iowa or the United States.
• Conduct an investigation of the chemical properties of limestone and discuss how these properties help explain how limestone rocks form.
• Investigate Iowa’s geological past and use it to support an explanation of how the limestone formed at Backbone State Park.
• Model how and why limestone can be found in some areas of Iowa but not others.
• Utilize resources on Iowa's geology from Iowa Land and Sky.

Related Resources

• Iowa Geology: 1995 Issue: Includes a fairly short article on the geology of Backbone.
• University of Iowa IIHR: The Natural History of Backbone State Park: Extensive 1995 report on the park, teacher background only.
• Irving Materials: What Is Limestone?: Student-appropriate info on limestone; includes an experiment.
• Iowa PBS: Iowa's Geologic Diversity: Gives basics of Iowa’s general geological history.