Pope Mega Group

The Pope Mega Group is a geologic unit found in the Illinois Basin of southern Illinois, southwestern Indiana, and western Kentucky. In Indiana and Kentucky its equitant is the Buffalo Wallow Group. This unit grades from sandstones at its base into mix of limestones and sandstone and then a shale at its top. In Southern Illinois oil wells are drilled into the Tar Springs formation.

Kinkaid Formation
Also known at the Kinkaid Limestone, this unit is made up of several smaller members. This unit ranges from 0' - 230 ' thick. The Grove Church Shale is at the top, followed by Members, Goreville Limestone, Cave Hill Shale, and Negli Creek Limestone.

Tobinsport Formation
A formation in Illinois containing 4 members that are linked to other formations in the Upper Pope Group. The Negli Creek Limestone of the Kinkaid formation to the west. Mt. Pleasant Sandstone, Bristow Sandstone, and Siberia Limestone. The Siberia is a thin tongue of the Menard formation.

Degonia Formation
This sandstone unit is 0-150' thick.

Clore Formation
This unit is 0-150’ thick. Its units include the Ford Station Limestone, Tygett Sandstone and Cora Limestone Members.

Palestine Formation
This sandstone unit is 0-120' thick.

Menard Formation
The Menard Limestone is a geologic formation in the Illinois Basin of southern Illinois, southwestern Indiana, and western Kentucky.

The type section of both the Walche Limestone Member and the Scottsburg Limestone Member are exposures in Walche's Cut, a railway cutting on the Illinois Central Railroad.

Waltersburg Formation
This formation is 0-100’ thick.

Vienna Formation
This limestone unit is 0-60' thick

Tar Springs Formation
This sandstone unit is 0-150' thick. The Tar Springs consists of interbedded sandstone and shale, creating closed reservoirs within the sand. For this reason it is the largest oil producing formation in Illinois. Estimated to have accounted for more than 60% of the oil production in the state.

Glen Dean Formation
The Glen Dean Formation is a geologic formation in Illinois, Indiana and Kentucky. It preserves fossils dating back to the Carboniferous period.

Hardinsburg Formation
The Hardinsburg Formation is a geologic formation in Illinois, Indiana and Kentucky. It preserves fossils dating back to the Carboniferous period.

Haney Formation
The Haney Formation is a geologic formation in Illinois, Indiana and Kentucky. It preserves fossils dating back to the Carboniferous period.

Fraileys Formation
The Fraileys Formation or Fraileys Shale is a geologic formation in Illinois. It preserves fossils dating back to the Carboniferous period.

Beech Creek Formation
The Beech Creek Formation is a geologic formation in Illinois, Indiana and Kentucky. It preserves fossils dating back to the Carboniferous period.

Cypress Formation
The Cypress Formation is a geologic formation in Illinois, Indiana and Kentucky. It preserves fossils dating back to the Carboniferous period.

Ridenhower Formation
The Ridenhower Formation is a geologic formation in Illinois. It preserves fossils dating back to the Carboniferous period. It includes the Reelsville Member, Sample Member and Beaver Bend Member.

Bethel Formation
The Bethel Formation is a geologic formation in Illinois, Indiana and Kentucky. It preserves fossils dating back to the Carboniferous period.