| Dubuque Formation Stratigraphic range: Ordovician | |
|---|---|
| Type | Formation |
| Underlies | Maquoketa Formation |
| Overlies | Galena Group |
| Location | |
| Region | Illinois, Minnesota |
| Country |  United States |
The Dubuque Formation is a geologic formation in Illinois, Iowa, Wisconsin and Minnesota. It preserves fossils dating back to the Ordovician period.
The Jordan Formation is a siliciclastic sedimentary rock unit identified in Illinois, Michigan, Wisconsin, Minnesota, and Iowa. Named for distinctive outcrops in the Minnesota River Valley near the town of Jordan, it extends throughout the Iowa Shelf and eastward over the Wisconsin Arch and Lincoln anticline into the Michigan Basin.
The Salem Formation is a geologic formation in Illinois, Indiana, Kentucky, and Missouri. It preserves fossils dating back to the Mississippian subperiod.
The Cedar Valley Group is a geologic group in Iowa and Illinois. It preserves fossils dating back to the Devonian period.
The Chouteau Limestone is a geologic formation in Illinois, Iowa, Kansas, and Missouri. It preserves fossils dating back to the Carboniferous period.
The Keokuk Limestone is a geologic formation in Illinois, Iowa and Missouri. It preserves fossils dating back to the Mississippian sub-period.
The Warsaw Formation is a geologic formation in Illinois, Iowa and Missouri. It preserves fossils dating back to the Mississippian subperiod.
The Kimmswick Limestone is an Ordovician geologic formation in Arkansas, Illinois and Missouri. Fossils occurring in the Kimmswick include corals, bryozoans, brachiopods, conodonts, trilobites, crinoids and mollusks.
The Maquoketa Formation is a geologic formation in Illinois, Indiana. Iowa, Kansas, Minnesota, Missouri, and Wisconsin. It preserves mollusk, coral, brachiopod and graptolite fossils dating back to the Darriwilian to Hirnantian stages of the Ordovician period.
The Shakopee Formation is a geologic formation in Illinois, Indiana, Wisconsin, and Minnesota. It preserves fossils dating back to the Ordovician period. It is named after the town of Shakopee, Minnesota, where the formation can be seen in bluffs along the Minnesota River
The Gower Formation is a geologic formation in Illinois and Iowa. It preserves fossils dating back to the Silurian period.
The Racine Dolomite is a geologic formation in Illinois and Wisconsin. It preserves fossils dating back to the Silurian period.
The Franconia Formation is a geologic formation in Wisconsin. It preserves fossils dating back to the Cambrian period.
The Oneota Formation is a geologic formation in the upper Midwest including Minnesota, Illinois, Indiana and Wisconsin. It preserves marine fossils dating back to the Ordovician period.
The Bonneterre Formation is an Upper Cambrian geologic formation which outcrops in the St. Francois Mountains of the Missouri Ozarks. The Bonneterre is a major host rock for the lead ores of the Missouri Lead Belt.
The Burlington Limestone is a geologic formation in Missouri, Iowa and the Midwest region. It preserves fossils dating back to the Mississippian subperiod.
The Oread Limestone is a geologic unit of formation rank within the Shawnee Group throughout much of its extent. It is exposed in Kansas, Nebraska, Missouri, Oklahoma, and Iowa. The type locality is Mount Oread within Lawrence, Kansas. It preserves fossils of the Carboniferous period. Although it has significant shale members, its limestone members are resistant and form escarpments and ridges. Limestone from the unit is a historic building material in Kansas, particularly in the early buildings of the University of Kansas; standing examples include Spooner Hall and Dyche Hall.
The St. Louis Formation is a geologic formation in Iowa. It preserves fossils dating back to the Carboniferous period.
The Stanton Formation is a geologic formation of limestone in Iowa, Nebraska, Missouri and Kansas. It preserves fossils dating back to the Carboniferous period. It is in the Upper Pennsylvanian series, forming the top of the Lansing Group.
The Cummingsville Formation is a geologic formation in Iowa and Minnesota. It preserves fossils dating back to the Ordovician period.
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