Munising Formation
Stratigraphic range: Cambrian-?Early Ordovician
Light-colored Musining Formation overlying the red Jacobsville Formation in Pictured Rocks National Lakeshore
Type	Formation
Sub-units	Miner's Castle Member, Chapel Rock Member, Basal Conglomerate, Eau Claire Formation
Underlies	Au Train Formation
Overlies	Jacobsville Sandstone
Thickness	1,700 ft (520 m)
Lithology
Primary	Conglomerate
Other	Anhydrite
Location
Region	Michigan  Ontario
Country	United States  Canada

The Munising Group or Formation is a 1,700 feet (520 m) thick, white to light grey^[1] Cambrian sedimentary unit that crops out in Michigan and (to a lesser extent) Ontario. At one end of its extent, it comprises a basal conglomerate overlain by the Chapel Rock Member and the Miners Castle Member; elsewhere, it comprises the Eau Claire, Galesville (=Dresbach), and Franconia Members. Anhydritic evaporite deposits are present in places.^[2] The conglomerate was deposited by rivers in flood, with the Chapel Rock member, which contains deltaic deposits, representing transgression as the conglomerate cones became submerged; the Miners Castle member was deposited further from the shoreline, representing shelf deposits.^[3] Its uppermost strata may be Early Ordovician in age, and contain conodonts, trilobites and phosphatic moulds of brachiopods, ostrocoderm fish and gastropods.^[4]

The Munising lies unconformably above the Jacobsville Formation.^[1]

v t e Chronostratigraphy of Michigan
Ph	Cz Q Pleistocene indet. Glacial till Mz J indet. Ionia Formation Pz C ⁋ Grand River Formation Saginaw Formation indet. Parma Sandstone M Bayport Limestone Coldwater Shale Marshall Sandstone Sunbury Shale D Upper indet. Antrim Shale Bedford Shale Berea Sandstone Ellsworth Shale Frasnian Squaw Bay Limestone Middle Givetian Squaw Bay Limestone Alpena Limestone Amherstburg Formation Anderdon Limestone Bell Shale Bois Blanc Formation Dundee Limestone Ferron Point Formation Long Lake Limestone Lucas Formation Rockport Quarry Limestone Rogers City Limestone Sylvania Sandstone Thunder Bay Limestone Lower Garden Island Formation S indet. Bertie Formation Byron Formation Bush Bay Formation Cordell Formation Hendricks Formation Lime Island Formation Pointe aux Chenes Formation Put-in-Bay Dolomite Raisin River Dolomite Rapson Creek Formation Rockview Formation Salina Group Schoolcraft Formation St. Ignace Dolomite Llandovery Cabot Head Shale Manitoulin Dolomite O Upper Sandbian Bill's Creek Shale Big Hill Formation Stonington Formation Middle Darriwilian Bill's Creek Shale Black River Formation Collingwood Shale Trenton Formation Lower Au Train Formation Є Munising Formation
pЄ	♇ Copper Harbor Conglomerate Freda Sandstone Jacobsville Sandstone Nonesuch Shale