Atoka Formation

{{Infobox rockunit

| name = Atoka Formation

| image =

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| type = Geologic formation

| age = Pennsylvanian

| prilithology = Sandstone

| otherlithology = Shale

| namedfor =

| namedby = J.A. Taff{{cite journal|last1=Taff|first1=J.A.|last2=Adams|first2=G.I.|title=Geology of the eastern Choctaw coal field|journal=Twenty-First Annual Report of the United States Geological Survey, 1899-1900, Part 2, General Geology, Economic Geology, Alaska|date=1900|pages=272, 273–274}}

| region = Arkansas, Oklahoma

| country = United States

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| unitof =

| subunits =

| underlies = Hartshorne Sandstone

| overlies = Bloyd Formation, Johns Valley Formation

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Named after Atoka County, Oklahoma, the Atoka Formation is a geologic formation in central and western Arkansas, eastern Oklahoma, central and western Texas, and eastern New Mexico.{{cite web|url=http://www.geology.ar.gov/geology/strat_arkvalley_ouachita.htm|title=Stratigraphic Summary of the Arkansas River Valley and Ouachita Mountains|publisher=Arkansas Geological Survey|access-date=2017-11-23|archive-date=2018-05-29|archive-url=https://web.archive.org/web/20180529114957/http://www.geology.ar.gov/geology/strat_arkvalley_ouachita.htm|url-status=dead}} It is the surface rock of the Boston Mountains and dominates exposures in the Frontal Ouachita Mountains of the Arkansas River Valley.

Sedimentology

The Atoka Formation is a sequence of marine sandstones, siltstones, and shales, and may be as thick at 25,000 feet in the Ouachita Mountains. The formation is conformable with the Bloyd Shale in the Boston Mountains and the Johns Valley Formation in the Ouachita Mountains.

Paleofauna

= Conodonts =

Cavusgnathus

: C. lauta{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

: C. sinuata{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

Gnathodus

: G. wapanuckensis{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

Gondolella

: G. bella{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

Hindeodella{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}
Ligonodina

: L. lexingtonensis{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

Ozarkodina

: O. recta{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

Polygnathodella

: P. attenuata{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

: P. ouachitensis{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

Streptognathodus

: S. cancellosus{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

: S. gracilis{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

= Foraminifera =

Fusulinella

: F. devexa{{cite journal|last1=Thompson|first1=M.L.|title=Studies of American fusulinids|journal=University of Kansas Paleontological Contributions, Protozoa|date=1948|volume=1|pages=184}}

: F. oliviformis{{cite journal|last1=Douglass|first1=R.C.|last2=Nestell|first2=M.K.|title=Fusulinids of the Atoka Formation, lower-middle Pennsylvanian, south-central Oklahoma|journal=Oklahoma Geological Survey Bulletin|date=1984|volume=136|pages=19-39|url=http://ogs.ou.edu/docs/bulletins/B136.pdf|access-date=7 June 2024}}

: F. prolifica{{cite journal|last1=Thompson|first1=M.L.|title=Fusulinids from the lower Pennsylvanian Atoka and Boggy formations of Oklahoma|journal=Journal of Paleontology|date=1935|volume=9|pages=291-306}}

Hyperammina

: H. bulbosa{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

Involutina

: I. semicronstrictus{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

Pesudostaffella

: P. atokensis{{cite journal|last1=Thompson|first1=M.L.|title=The fusulinid genus Staffella in America|journal=Journal of Paleontology|date=1935|volume=9|pages=111-120}}

Profusulinella

: P. fittsi{{cite journal|last1=Thompson|first1=M.L.|title=Fusulinids from the lower Pennsylvanian Atoka and Boggy formations of Oklahoma|journal=Journal of Paleontology|date=1935|volume=9|pages=291-306}}

: P. millcreekensis{{cite journal|last1=Douglass|first1=R.C.|last2=Nestell|first2=M.K.|title=Fusulinids of the Atoka Formation, lower-middle Pennsylvanian, south-central Oklahoma|journal=Oklahoma Geological Survey Bulletin|date=1984|volume=136|pages=19-39|url=http://ogs.ou.edu/docs/bulletins/B136.pdf|access-date=7 June 2024}}

Reophax

: R. fittsi{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

: R. tumidulus{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

Thurramminoides

: T. sphaeroidalis{{Cite book |last=Johansson |first=F. C. Jr. |title=Micropaleontology of the Wesley Johns Valley and Atoka Formations of the Ouachita Mountains of Oklahoma (PhD. dissertation) |publisher=University of Wisconsin |year=1960 |pages=45}}

=Trace Fossils=

Conostichus

: C. arkansanus{{cite journal|last1=Branson|first1=Carl C.|title=New records of the Scyphomedusan Conostichus|journal=Oklahoma Geology Notes|date=May 1961|volume=21|issue=5|pages=130–138|url=http://ogs.ou.edu/docs/geologynotes/GN-V21N5.pdf|access-date=28 January 2018}}

References

Category:Pennsylvanian Arkansas

Category:Pennsylvanian Oklahoma

Category:Carboniferous southern paleotropical deposits

Category:Sandstone formations of the United States

Category:Shale formations of the United States