Bluestone Formation
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| Bluestone Formation | |
|---|---|
| Stratigraphic range: Serpukhovian | |
 Outcrop near Camp Creek, West Virginia, showing cyclical deposits of the Pride Shale Member | |
| Type | Formation |
| Unit of | Mauch Chunk Group |
| Sub-units | "upper member", Bramwell Member, "red member", "gray member", Glady Fork Sandstone Member, Pride Shale Member |
| Underlies | Pocahontas Formation |
| Overlies | Princeton Sandstone |
| Location | |
| Region | West Virginia |
| Country | United States |
The Bluestone Formation is a geologic formation in West Virginia. It is the youngest unit of the Upper Mississippian-age Mauch Chunk Group. A pronounced unconformity separates the upper boundary of the Bluestone Formation from sandstones of the overlying Pennsylvanian-age Pocahontas Formation.[1]
Two formally named subunits of the Bluestone Formation, the Bramwell and Pride Shale Members, are quite fossiliferous. Plant fossils allow the top of the Bluestone Formation to be correlated with the Namurian A-Namurian B boundary, the European equivalent of the Mississippian-Pennsylvanian boundary. Conodonts belonging to the Adetognathus unicornis or lower Rhachistognathus muricatus conodont zones have been found in the Bramwell Member. This would make the Bluestone Formation the youngest occurrence of Mississippian-type conodonts in eastern North America.[2] A diverse bivalve fauna was present in both the Bluestone Formation and the older Hinton Formation.[3] Brachiopods were also fairly diverse, though not as dominant in the ecosystem as bivalves.[4] Among the most abundant fossils were fossilized tubes of Microconchus hintonensis, a microconchid.[5] The Pride Shale Member has produced Tanypterichthys pridensis, an endemic species of deep-bodied palaeonisciform fish.[6]
