Using Geologic Maps

The distribution of materials at and below the land surface affects everyone who lives on this planet. In Maine, earth materials control everything from searching for ground water to siting a house foundation to protecting the environment to mining for precious gems. To make informed decisions, there needs to be a system which portrays the complicated pattern of rocks and earth materials which form the land surface. Geologic maps fill this need, portraying information such as the distribution of rock types and unconsolidated materials such as clay, sand, and gravel; landslide and erosion hazards; ground water availability; and much more. Browse the following pages to find out how to become a more informed reader of geologic maps.

Reading and Understanding Geologic Maps

Reading Maps with a Critical Eye: Becoming an Informed Map Reader

Use the links in the following list to learn more about the geologic maps produced by the Maine Geological Survey. The Description link will provide a description of the map series, and links to the map explanation and sidebar. The How to Read link will provide tips on how to read the geologic map.

Bedrock Geology
   Map series Description How to read
   Bedrock View View

Coastal Marine Geology
   Map series Description How to read
   Bluffs View View
   Marine Geologic Environments View
   Coastal Sand Dune Maps View View
   Inner Continental Shelf View

Economic Geology
   Map series Description How to read
   Peat Resource Evaluation View

Geologic Hazards
   Map series Description How to read
   Landslide Hazards View View
   Landslide Susceptibility View

Surficial Geology
   Map series Description How to read
   Surficial - detailed View View
   Surficial - reconnaissance View
   Surficial - 1:250,000 View
   Surficial Materials View View

Water Resources
   Map series Description How to read
   Sand and Gravel Aquifers View View
   Bedrock Ground-Water View
   National Wetlands Inventory View

Last updated on June 13, 2018