What's Under My Feet? Learning to Use a Geologic Map

Try this activity from the Association of American State Geologists!

  1. Using Google Maps or another map location software, find the location of your school or another place in your state.
  2. Next, visit the web site of the Association of American State Geologists (AASG) at www.stategeologists.org.
  3. At the AASG web site map, click on your state. This will take you to your state geological survey’s web site. At the site, look for any geologic maps available. They can be statewide geologic maps and/or maps that cover your place or area of interest.
  4. Find your chosen location on the geologic map. Notice the color or pattern and any letter symbol on the map at your location.
  5. On the map key (sometimes known as the description of map units), look for the color, pattern and/or letter code you chose from the map. Think about these questions:
    • What rock types are described? Are minerals named? If so, what are the rocks and minerals named?
    • A grouping of rock types may have a name. What is it?
  6. You have just used a geologic map to start learning about the geology at your chosen location. Refer to the portion of this poster entitled How do you read a geologic map? Now, look for more on the geologic map of your state. Put your new map-reading skills to work by finding another location and repeating this process.