Bayport Limestone

Bayport Limestone
State Michigan
Name Bayport Limestone
Geologic age Mississippian
Lithologic constituents
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Carbonate > Dolostone (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)
Sedimentary > Chemical > Chert (Bed)banded chert
Sedimentary > Chemical > Evaporite (Bed)
Comments Secondary unit description from USGS Geologic Names lexicon (ref. MI016): The Bayport limestone consists of sandy yellow limestones, cross-bedded white sandstone, and a little dolomite. Unit is 20 to 50+ feet thick. The Bayport is the top unit in the Grand Rapids group or series. Maximum thickness of the Bayport is about 37 m but in most places is 15 to 30 m thick. Unit is lithologically variable, but is predominantly carbonate. It also contains significant amounts of sandstone and minor quantities of shale, bedded chert, and evaporites.

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:

NGMDB product
Counties Barry - Calhoun - Eaton - Genesee - Huron - Ingham - Ionia - Jackson - Kent - Lake - Livingston - Missaukee - Muskegon - Newaygo - Ogemaw - Ottawa - Roscommon - Shiawassee - Tuscola - Wexford