The Cincinnati Group is a geologic group in Kentucky, Ohio and Indiana. It is Upper Ordovician.
The Harrodsburg Limestone is a geologic formation, a member of the Sanders Group of Indiana Limestone, of Mississippian age. It was named for Harrodsburg in southern Monroe County, Indiana by T. C. Hopkins and C. E. Siebenthal. It is made up primarily of calcarenite and calcirudite. It also may include some beds of dolomite and shale.
The Chattanooga Shale is a geologic formation in Alabama, Arkansas, Kentucky, Missouri and Tennessee. It preserves conodont fossils dating to the Devonian Period. It occurs mostly as a subsurface geologic formation composed of layers of shale. It is located in Eastern Tennessee and also extends into southeastern Kentucky, northeastern Georgia, and northern Alabama. This part of Alabama is part of the Black Warrior Basin.
The Davis Formation is a geologic formation in Indiana and Missouri. It preserves fossils dating back to the Cambrian period.
The Big Clifty Formation is a geologic formation in Indiana. It preserves fossils dating back to the Carboniferous period.
The Osgood Formation, also known as the Osgood Shale is a geologic formation in Indiana, Kentucky, and Ohio. It preserves fossils dating back to the Silurian period.
The Laurel Formation, also known as the Laurel Limestone or the Laurel Dolomite, is a geologic formation in Indiana and Kentucky. It preserves fossils dating back to the Silurian period.
The Fort Scott Limestone or Fort Scott Subgroup is a geologic formation in Illinois, Kansas, Missouri, and Oklahoma. It preserves fossils dating back to the Carboniferous period.
The Fraileys Formation or Fraileys Shale is a geologic formation in Illinois. 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 Bond Formation is a geologic formation in Illinois, Kentucky and Indiana. It preserves fossils dating back to the Carboniferous period.
The Warsaw Formation is a geologic formation in Illinois, Iowa and Missouri. It preserves fossils dating back to the Mississippian subperiod.
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 Powell Formation or Powell Dolomite is a geologic formation in northern Arkansas, southeast Missouri and Virginia. It contains gastropod, cephalopod, and trilobite fossils dating back to the Ordovician Period.
The Cotter Formation is a geologic formation in Arkansas, Missouri, Oklahoma and in Virginia. It preserves fossils dating back to the Ordovician period.
The Franconia Formation is a geologic formation in the upper mid-western United States, with outcroppings found in Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio, and Wisconsin. It preserves fossils dating back to the Cambrian period. It was named the Franconia Formation due to the first published documentation of exposures in vicinity of Franconia, Minnesota in the 1897 Ph.D. dissertation by Charles P. Berkley at the University of Minnesota titled Geology of the St. Croix Dalles. The Franconian stratigraphic stage was named after this formation.
The Potosi Formation is a geologic formation in Missouri and Indiana. It preserves fossils dating back to the Cambrian period.
The Burlington Limestone is a geologic formation in Missouri, Iowa and the Midwest region. It preserves fossils dating back to the Mississippian subperiod.
The Fern Glen Formation is a geologic formation in eastern and southeastern Missouri. It preserves fossils dating back to the Osagean Series of the Mississippian subperiod.
The Bowling Green Dolomite is a geologic formation in Missouri. It preserves fossils dating back to the Silurian period.
