# Borden Formation

The Mississippian Borden Group (sometimes Borden Formation) is a mapped bedrock unit in Kentucky, Indiana, Illinois, Ohio, West Virginia, and Tennessee. It has many members, which has led some geologists to consider it a group (for example in Indiana) rather than a formation (for example in Kentucky).

## Fossils

* Scyphozoans: Conularia sp. (from Borden Formation), Paraconularia sp. (from Coral Ridge Member, New Providence Shale)
* Hexactinellid Sponges (from Muldraugh Formation)
* Brachiopods: Orthotetes keokuk (from Borden Formation), Orbiculoidea (from Coral Ridge Member, New Providence Shale)
* Trilobite: Phillibole conkini (Coral Ridge Member, New Providence Formation, Borden Group)
* Cephalopods: Cantabricanites greenei, Polaricyclus ballardensis, Winchelloceras knappi (all from Coral Ridge Member, New Providence Formation, Borden Group), Muenstroceras oweni, M. parallelum, Kazakhstania colubrella, Imitoceras ixion, Masonoceras kentuckiense, Merocanites drostei, Dzhaprakoceras sp., Polaricyclus bordenensis, Winchelloceras allei (all from Nada and Cowbell Members)
* Crinoids: Pachyocrinus aequalis (from Muldraugh Mbr.), Gilmocrinus kentuckyensis (from Muldraugh Mbr.), Rhodocrinites barrisi divergens, Gilbertsocrinus tuberculosus, Gilbertsocrinus typus, Actinocrinites eximius, Actinocrinites scitulus, Blairocrinus protuberatus, Steganocrinus, Uperocrinus pyriformis, Uperocrinus acuminatus, Eretmocrinus cloelia, Macrocrinus konincki, Dorycrinus quinquelobus, Aorocrinus nodulus, Agaricocrinus planoconvexus, Agaricocrinus inflatus, Dichocrinuspocillum Dichocrinus, Paradichocrinus liratus, Platycrinites glyptus, Platycrinites planus, Platycrinities spinifer, Cyathocrinites iowensis, Barycrinus spurious, Costalocrinus cornutus, Meniscocrinus, Pellecrinus obuncus, Atelestocrinus kentuckyensis, Holcocrinus spinobrachiatus, Blothrocrinus swallovi, Coeliocrinus subspinosus, Decadocrinus scalaris, Taxocrinus, Synbathocrinus dentatus, Halysiocrinus dactylus (from Nada Mbr.).
* Blastoids: Granatocrinus kentuckyensis (from New Providence Shale)
A rare soft-bodied fossil that was recovered from the Farmers Member of the Borden Formation in northeastern Kentucky was interpreted as a chondrophorine float (an internal anatomical feature).
* Fossil brachiopods (Rhynchonelliformea) in ironstone concretion (Nancy Member)
* Gilbertsocrinus typus, an extinct crinoid from the Borden Formation
* Platycrinites hemisphericus, another crinoid
* Fossil scallop in ironstone concretion (Nancy Member)

## Trace fossils

Zoophycos is present in the turbidites of the Farmers Member of the Borden Formation in Kentucky.
* Zoophycos from turbidites of Farmers Member of Borden Formation at mile marker 135, I-64, Kentucky
* Another Zoophycos trace fossil from Kentucky
* Trace fossils in sandstone (Henley Member)

## Stratigraphy

There are three members of the Borden Group in Indiana.

### Edwardsville Formation

The Edwardsville Formation is a geological structure in the Borden Group, of the Lower Mississippian sub system, (Osagean, late Tournaisian). Crinoids fossils can be found in the formation.

### New Providence Shale

The New Providence Shale is a geologic formation in Indiana. It is a basal clay-shale geologic formation in Indiana named by Charles Butts and William W. Borden in the 1874 after New Providence, Indiana (now Borden).

### Spickert Knob Formation

The Spickert Knob Formation is a geologic formation in Indiana.