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.