Geologic Maps 
Geology 100 
Geology for Environmental Scientists
Geologic Map of the US
Symbols found on geologic maps
Horizontal Strata
Geologic map of 
part of the Grand 
Canyon. Each 
color represents a 
different 
formation.
Inclined Strata
Dome
Geologic map 
of the Black 
Hills of South 
Dakota, a large 
structural dome.
The Black Hills of South Dakota are a structural dome.
Basin
Bedrock geologic map of the Great Lakes region
Michigan Basin
Surficial geology map of the Great Lakes region
Plunging Folds
Geologic 
map of 
Valley and 
Ridge of 
Pennsylvania
Satellite image of 
central 
Appalachians 
Area in last 
picture
False color satellite image of folded sedimentary 
rocks, central Appalachian Mountains.
Faults
Geologic map of thrust belt in Montana
Angular 
Unconformity
Geologic Map 
of the southern 
Appalachians. 
Note the 
Nashville 
Dome, folds, 
faults, and an 
unconformity.
Method for constructing a geologic cross section

Geologic maps