Earth:Washington Formation
| Washington Formation Stratigraphic range: Permian | |
|---|---|
_2.jpg) Bituminous coal (Washington Coal, Upper Pennsylvanian; Ohio) | |
| Type | Formation |
| Unit of | Dunkard Group[1] |
| Sub-units | Upper Washington Jollytown coal |
| Underlies | Greene Formation |
| Overlies | Waynesburg Formation |
| Lithology | |
| Primary | limestone, sandstone, coal |
| Other | shale |
| Location | |
| Region | Ohio and West Virginia |
| Country | United States |
The Washington Formation is a coal, sandstone, and limestone geologic formation located in Ohio, Pennsylvania and West Virginia.[1] It dates back to the Lower Permian period, with its base at or near the Permian/Carboniferous boundary.[2][3] The Washington formation and the Dunkard Group as a whole was deposited at a time when the continents were in the process of forming the "Super Continent" Pangaea as well as a gradual drop in sea levels.[4] The result during this period was coals being thinner and impure with high ash content. The limestones found with in the formation are exclusively freshwater deposits.
Paleofauna
The paleofauna of the Washington Formation is considered similar to that of the Texas Red Beds, sharing many fish and tetrapod taxa. Some of the taxa listed suggest an Artinskian age.[5] Lucas et al 2013 discusses the fauna of the formation.[5]
Synapsida
| Genus | Species | Notes |
|---|---|---|
| Dimetrodon | D.limbatus | Stated to be from a large specimen.[5] |
| Edaphosaurus | E.boanerges | A large edaphosaurid.[5] |
| Ophiacodon | O.retroversus | An ophiacodontid.[5] Stated to be large.[6] |
| Sphenacodontia indet. | Indeterminate | An indeterminate sphenacodont.[7] |
Reptiliomorpha
| Genus | Species | Notes |
|---|---|---|
| Diadectes | D. sp. | A large diadectid.[5] |
| Protorothyris | P.archeri | A protorothyrid.[5] |
Amphibia
| Genus | Species | Notes |
|---|---|---|
| Eryops | E.megacephalus | A large temnospondyl.[5] |
| Acheloma | A.sp | A terrestrial temnospondyl.[5] |
| Trimerorhachis | T.insignis | A fully aquatic temnospondyl.[5] |
| Diploceraspis | D.burkei | An aquatic lepospondyl with large outward growths of the head.[5] |
| Zatrachys | Z.sp | An armored terrestrial temnospondyl.[5] |
| Edops | E.sp | An aquatic temnospondyl.[5] |
| Megamolgophis | M.agostini | A possible lysophorian.[5] |
| Brachydectes | B.sp | A lysophorian.[5] |
Selachia
| Genus | Species | Notes |
|---|---|---|
| Orthacanthus | O.texensis | A large selachian.[5] |
| Xenacanthus | X.luederensis | A small selachian.[5] |
| Barbclabornia | B.luederensis | A giant selachian.[8] |
Osteichthyes
| Genus | Species | Notes |
|---|---|---|
| Ectosteorhachis | E.sp | A large lobe finned fish.[5] |
| Palaeoniscoidea indet. | Indet. | Indeterminate paleoniscoids.[5] |
| Monongahela | M.sp. | A dipnoan.[5] |
References
- ↑ 1.0 1.1 Berryhill, Henry L. Jr.; Swanson, Vernon E. (1962). "Geological Survey research 1962; Short papers in geology and hydrology". U.S. Geological Survey Professional Paper 450-C: 43–46. https://pubs.usgs.gov/pp/0450c/report.pdf. Retrieved 30 June 2018.
- ↑ Wayne Martin, Bernard Henniger (1965). "The Hockingport and Waynesburg Sandstones (Pennsylvanian and Permian) of the Dunkard Group: ABSTRACT". AAPG Bulletin 49. doi:10.1306/a66335b4-16c0-11d7-8645000102c1865d. ISSN 0149-1423.
- ↑ M. A. Rendina, Wayne D. Martin (1985). "Provenance of Selected Sandstones and Mud Rocks of Dunkard Group (Upper Pennsylvanian-Permian) in Ohio, West Virginia, and Pennsylvania: ABSTRACT". AAPG Bulletin 69. doi:10.1306/94885417-1704-11d7-8645000102c1865d. ISSN 0149-1423.
- ↑ Haq, Bilal U.; Schutter, Stephen R. (2008-10-03). "A Chronology of Paleozoic Sea-Level Changes". Science 322 (5898): 64–68. doi:10.1126/science.1161648. ISSN 0036-8075. PMID 18832639. Bibcode: 2008Sci...322...64H. http://dx.doi.org/10.1126/science.1161648.
- ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 Lucas, Spencer G. (2013-11-01). "Vertebrate biostratigraphy and biochronology of the upper Paleozoic Dunkard Group, Pennsylvania–West Virginia–Ohio, USA". International Journal of Coal Geology. SI:Dunkard Group Geology 119: 79–87. doi:10.1016/j.coal.2013.04.007. ISSN 0166-5162. Bibcode: 2013IJCG..119...79L. https://www.sciencedirect.com/science/article/pii/S0166516213001249.
- ↑ Olson, Everett C. (1970-02-05). "Trematops Stonei sp. nov. (Temnospondyli Amphibia) from the Washington Formation, Dunkard Group, Ohio". Kirtlandia 8: 1–12. https://biostor.org/reference/193101.
- ↑ House, Ashley (2025). "A new sphenacodont synapsid from the early Permian Washington Formation of Ohio, USA". https://vertpaleo.org/wp-content/uploads/2025/12/2025_SVP_Program_Final_Final.pdf.
- ↑ Johnston, Gary (2003). "Dentitions of Barbclabornia (new genus, Chondrichthyes: Xenacanthiformes) from the Upper Palaeozoic of North America". https://www.researchgate.net/publication/230047345.
Template:Chronostratigraphy of Ohio
Template:Chronostratigraphy of Pennsylvania
Template:Chronostratigraphy of West Virginia
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