| State | Michigan |
|---|---|
| Name | Saginaw Formation |
| Geologic age | Pennsylvanian |
| Lithologic constituents |
Major
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)
Minor
Sedimentary > Carbonate > Limestone (Bed)
Sedimentary > Coal (Bed)
|
| Comments | Secondary unit description from USGS Geologic Names lexicon (ref. MI016): Revised the Saginaw to the Saginaw group. Unit is composed of material of fresh water, brackish water, and marine origin, and consists of sandstone, shale, coal, and limestone. Comprises many cyclical formations, one which (Verne formation) contains a persistent shaly marine limestone member that makes it convenient to divide the group into pre- and post-Verne cyclical formations. Thickness of group is 400 feet. Overlies the Parma sandstone wherever that formation is present; in some areas, directly overlies the Bayport formation, as in area immediately north of Jackson; in several localities, may rest directly on Napoleon sandstone. Underlies Grand River group. The Saginaw is of Pennsylvanian age. |
| References | Milstein, Randall L. (compiler), 1987, Bedrock geology of southern Michigan: Geological Survey Division, Michigan Dept. of Natural Resources, scale 1:500,000. |
| NGMDB product | |
| Counties | Arenac - Barry - Bay - Calhoun - Clare - Clinton - Eaton - Genesee - Gladwin - Gratiot - Huron - Ingham - Ionia - Isabella - Jackson - Kent - Lake - Livingston - Mecosta - Midland - Missaukee - Montcalm - Newaygo - Ogemaw - Osceola - Roscommon - Saginaw - Shiawassee - Tuscola - Wexford |