The Iowa Geoscience Education Information Network

Explore Iowa Geology

Iowa's Landscapes

This is a brief geologic introduction to our plains, hills, valleys, parks, and backyards.  Our land is an extraordinary natural resource that provides opportunities for employment, agriculture, conservation, recreation, and exploration.  Geology is an interdisciplinary branch of science that enables us to discover, characterize/describe, and preserve our natural resources and environment. 

The foundation of Iowa’s landscapes begins with bedrock (igneous, metamorphic, and sedimentary).  The Earth has a long (4.57 billion year) history! Much of Iowa’s geologic history is known from a sedimentary rock type called limestone. Limestone is produced in shallow seas and often contains marine fossils.  Most of our limestone ranges in age from 485 to 380 million years.  The rock record and the fossils it contains provides evidence that our state has been part an ocean floor! What type of bedrock is under your backyard?  Limestone is an incredible natural resources for our state!

Over the past 2 million years glaciers have buried much of our bedrock with sediment.  Some glacial landforms are still present while others have been changed/moved by water, wind, gravity, and humans. Iowa contains eight distinct landform regions, which region does your favorite state park fall in Google Earth? Learning with Google Earth ckick here!

These glacial sediments contain a diverse mix of minerals and rocks.  Weathering (mechanical, chemical, and biological) and thousands of years of prairie (growth and decay) have produced some of the most fertile and productive soils on Earth.

Ask a geologist

Iowa Geological Survey

Further information: 

University of Northern Iowa UNI - EDMAP program

Iowa’s Geologic Past – Three Billion Years of Change by Wayne J. Anderson

Landforms of Iowa, by Jean C. Prior

From Rift to Drift – Iowa’s Story in Stone, by Jack C. Troeger