| Upper Pope Group | |
|---|---|
| Stratigraphic range: Carboniferous | |
| Type | Geological group |
| Sub-units |
|
| Overlies | Lower Pope Group |
| Lithology | |
| Primary | Sandstone, Limestone, Shale |
| Location | |
| Region | Illinois Basin |
| Country | United States of America |
The Upper Pope Group is a geologic unit found in the Illinois Basin of southern Illinois, southwestern Indiana, and western Kentucky.[1][2] 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.[3] In Sothern Illinois oil wells are drilled into the Tar Springs formation.[4]
Stratigraphy
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.[5]
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.[6][7][8]
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.
Energy Production
References
- ↑ Stamm, N. 2020b, Geologic Unit: Menard, National Geologic Map Database, Geolex, United States Geological Survey, Reston, Virginia.
- ↑ Willman, H.B., Atherton, Elwood, Buschbach, T.C., Collinson, Charles, Frye, J.C., Hopkins, M.E., Lineback, J.A., and Simon, J.A., 1975, Handbook of Illinois stratigraphy: Illinois Geological Survey Bulletin, no. 95, 261 p.
- ↑ Kolata, D.R. 2005, Bedrock Geology of Illinois: Champaign, Ill. U.S. Geological Survey (Report). Retrieved 16 December 2023.
- ↑ Askari, Zohreh; Lasemi, Yaghoob (16 December 2022). "Geological characterization and ROZ potential of the Tar Springs Sandstone". U.S. Department of Energy Office of Scientific and Technical Information.
- ↑ Gray, Henry H. (1978). Buffalo Wallow Group Upper Chesterian (Mississippian) of Southern Indiana (Report). Indiana Geological & Water Survey.
- ↑ "Walche Limestone Member". igws.indiana.edu.
- ↑ Swann, David Henry (November 17, 1963). "Classification of Genevievian and Chesterian (late Mississippian) rocks of Illinois". Report of Investigations No. 216 – via www.ideals.illinois.edu.
- ↑ Droste, J. B., and Keller, S. J., 1995, Subsurface stratigraphy and distribution of oil fields of the Buffalo Wallow Group (Mississippian) in Indiana: Indiana Geological Survey Bulletin 63, 24 p.