Garden Island Formation

Garden Island Formation
State Michigan
Name Garden Island Formation
Geologic age Early Devonian
Lithologic constituents
Major
Sedimentary > Carbonate > Dolostone (Bed)
Sedimentary > Carbonate > Limestone (Bed)
Comments Secondary unit description from USGS Geologic Names lexicon (ref. MI016): Named the Garden Island formation for Garden Island, northeastern MI. Consists of dolomite and dolomitic limestone which occupies a position between Silurian St. Ignace formation and Middle Devonian Bois Blanc formation. Thickness at type locality is 3 feet; maximum thickness probably not more than 25 feet, and average thickness not more than 15 feet. The Garden Island is of Early Devonian age.
References

Milstein, Randall L. (compiler), 1987, Bedrock geology of southern Michigan: Geological Survey Division, Michigan Dept. of Natural Resources, scale 1:500,000.

USGS Geologic Names lexicon found at: http://ngmdb.usgs.gov/Geolex/

https://ngmdb.usgs.gov/Geolex/search

NGMDB product
Counties Monroe