Pitkin Formation
| Pitkin Formation | |
|---|---|
| Stratigraphic range: Upper Visean-Serpukhovian[1] | |
| Type | Formation |
| Sub-units | Imo Shale |
| Underlies | Hale Formation |
| Overlies | Fayetteville Formation |
| Thickness | up to and over 400 feet[2] |
| Lithology | |
| Primary | Limestone[1] |
| Other | Shale |
| Location | |
| Region | Arkansas |
| Country | United States |
| Type section | |
| Named for | Pitkin post office, Washington County, Arkansas[3] |
| Named by | George Irving Adams and Edward Oscar Ulrich |
The Pitkin Formation, or Pitkin Limestone, is a fossiliferous geologic formation in northern Arkansas that dates to the Chesterian Series of the late Mississippian.[4] This formation was first named the "Archimedes Limestone" by David Dale Owen in 1858, but was replaced in 1904.[3] The Pitkin conformably overlies the Fayetteville Shale and unconformably underlies the Pennsylvanian-age Hale Formation. Some workers have considered the top of the Pitkin Formation to be a separate formation called the Imo Formation. However more recently, others have considered it as an informal member of the Pitkin Formation.
Paleofauna
Early work aimed at creating a comprehensive list for all fossils found in the Pitkin Formation was done by Easton in 1943.[1] Unless otherwise stated, all species below can be found in his 'Fauna of the Pitkin Formation.'
Formanifera
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Porifera, Sponges
Scyphozoa
- Conularia Originally considered to be a gstropod.
Anthozoa, Corals
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Aulopora from the Silica Formation of Ohio. -
Pleurodictyum americanum from the Givetian Kashong Shale (Hamilton Group) of Livingston County, New York. -
Syringopora from the Boone Formation of Arkansas.
Blastoidea
Crinoidea, Sea Lilies
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Cyathocrinus goniodactylus, on display at Galerie de paléontologie et d'anatomie comparée in Paris. -
Fossil of Scytalocrinus from Carboniferous of the United States
Ophiuroidea, Brittle Stars
This group was originally place under Stelleroidia in early studies.[1]
- A. singulatus
Echinoidea, Sea Urchins
Worms
Previous studies have grouped these diverse animals into a single, obsolete taxon: Vermes.[1]
Bryozoa, "Moss-animals"
| Stereo image | |||
|---|---|---|---|
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| Fossilized skeleton of Archimedes Bryozoan. | |||
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Brachiopoda
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Bivalvia, Bivalves
This group was also referred to by another name in earlier studies: Pelecypoda.[1]
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Scaphopoda, Tusk Shells
Gastropoda, Snails
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Cephalopoda
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Trilobita
- G. pustulosus
- K. chesterensis
- K. pitkinensis[14]
- P. mucronatus
Ostracoda
- G. optina
- P. fayettevillensis
Vertebrata
Plantae, Plants
"Encrusting Algae" has been reported but not assigned to any genus.[1]
- A. cordillerensis[5]
Unidentified
Following is a list of fossils also found in the Pitkin by Easton in 1943 that have gone unidentified.[1]
- A "Cup Coral"
- A member of the genus Pentremites
- Three species within Agassizocrinus
- Two species within Scytalocrinus
- A totally unidentifiable Crinoid
- Two species of Bellerophon
- Two species of Gosseletina
- Two species of Leptoptygma
- Two Species of Strobeus
- One species each of Composita and Echinoconchus
- Two species of Cypricardella
- Two species of Coloceras, one of which may actually be Leuroceras
- One species of Dolorthoceras
- An unnamed shark spine
See also
References
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am Easton, William H., The Fauna of the Pitkin Formation of Arkansas., Journal of Paleontology: vol. 17:2. March, 1943.
- ^ McFarland, John David (2004) [1998]. "Stratigraphic summary of Arkansas" (PDF). Arkansas Geological Commission Information Circular. 36: 12–13.
- ^ a b Adams, G.; Ulrich, E. (1904). "Zinc and lead deposits of northern Arkansas". U.S. Geological Survey Professional Paper. 24: 27, 109.
- ^ Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to thefix Paleobiology Database". Archived from the original on 31 July 2014. Retrieved 8 July 2014.
{{cite web}}:|author=has generic name (help); Unknown parameter|deadurl=ignored (|url-status=suggested) (help) - ^ a b c d e f g h i j k l m n o p q r s t u v Brenckle, Paul (1977). "Foraminifers and other calcareous microfossils from Late Chesterian (Mississippian) strata of northern Arkansas" (PDF). Oklahoma Geological Survey Guidebook. 18: 73–87. Retrieved 3 February 2018.
- ^ a b c d e f Nodine-Zeller, Doris E. (1977). "Microfauna from Chesterian (Mississippian) and Morrowan (Pennsylvanian) rocks in Washington County, Arkansas, and Adair and Muskogee Counties, Oklahoma" (PDF). Oklahoma Geological Survey Guidebook. 18: 89–99. Retrieved 3 February 2018.
- ^ a b c d Webb, Gregory., 1987., The Coral Fauna of the Pitkin Formation (Chesterian), Northeastern Oklahoma and Northwestern Arkansas. Journal of Paleontology vol. 61:3
- ^ a b Webb., Gregory., 1990., A New Tabulate Coral Species from the Pitkin Formation (Chesterian) of north-central Arkansas. Journal of Paleontology vol. 64:4.
- ^ a b c d Horowitz, Alan S.; Macurda Jr, D. B. (1977). "Late Mississippian and Early Pennsylvanian blastoids from northeastern Oklahoma and northwestern Arkansas" (PDF). Oklahoma Geological Survey Guidebook. 18: 169–170. Retrieved 31 January 2018.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x Strimple, Harrell L. (1977). "Chesterian (Upper Mississippian) and Morrowan (Lower Pennsylvanian) crinoids of northeastern Oklahoma and northwestern Arkansas" (PDF). Oklahoma Geological Survey Guidebook. 18: 171–176. Retrieved 30 January 2018.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai Horowitz, Alan S. (1977). "Late Mississippian and Early Pennsylvanian bryozoan faunas of Arkansas and Oklahoma: a review" (PDF). Oklahoma Geological Survey Guidebook. 18: 101–105. Retrieved 3 February 2018.
- ^ Henry, Thomas W.; Gordon Jr., Mackenzie (January 1985). "Chesterian davidsoniacean and orthotetacean brachiopods, Ozark region of Arkansas and Oklahoma". Journal of Paleontology. 59 (1): 32–59. JSTOR 1304826.
- ^ a b c d e f Saunders, W. Bruce; Manger, Walter L.; Gordon Jr., Mackenzie (1977). "Upper Mississippian and Lower and Middle Pennsylvanian ammonoid biostratigraphy of northern Arkansas" (PDF). Oklahoma Geological Survey Guidebook. 18: 117–137. Retrieved 1 February 2018.
- ^ Brezinski, David K. (31 March 2017). "Some New Late Mississippian Trilobites from Oklahoma and Arkansas". Annals of Carnegie Museum. 84 (2): 173–178. doi:10.2992/007.084.0203.