Cleveland Shale

Last updated
Cleveland Shale
Stratigraphic range: Famennian
~362.6–360.1  Ma
O
S
D
C
P
T
J
K
Pg
N
Shale 02 - Great Falls of Tinkers Creek.jpg
Cleveland Shale (below) and Berea Sandstone of the Bedford Formation at the Great Falls of Tinkers Creek near Bedford, Ohio
Type Formation
Unit of Ohio Shale
Underlies Bedford Shale
Overlies Chagrin Shale
Lithology
Primary Shale
Other Pyrite
Location
Coordinates 39°24′N83°36′W / 39.4°N 83.6°W / 39.4; -83.6
Approximate paleocoordinates 31°18′S32°12′W / 31.3°S 32.2°W / -31.3; -32.2
RegionFlag of Ohio.svg  Ohio
CountryFlag of the United States.svg  United States
Type section
Named for Cleveland, Ohio
Named by John Strong Newberry
Year defined1870
Usa edcp relief location map.png
Gold pog.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Cleveland Shale (the United States)
USA Ohio relief location map.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Gold pog.svg
Cleveland Shale (Ohio)

The Cleveland Shale, also referred to as the Cleveland Member, is a shale geologic formation in the eastern United States.

Contents

Identification and name

The Cleveland Shale was identified in 1870 and named for the city of Cleveland, Ohio. John Strong Newberry, director of the Ohio State Geological Survey, first identified the formation in 1870. [1] He called it the "Cleveland Shale" and designated its type locality at Doan Brook [2] near Cleveland. [1] Details of the type locality and of stratigraphic nomenclature for this unit as used by the U.S. Geological Survey are available on-line at the National Geologic Map Database. [3]

Description

The primary minerals in the Cleveland Shale are chlorite, illite, pyrite, and quartz. [4] [lower-alpha 1] Underground, the Cleveland Shale is black, [5] [6] [7] [8] dull grayish-black, [9] bluish-black, or brownish-black [4] in color. In exposed outcrops, it weathers to red, [9] reddish-brown, [2] or medium brown. [4] Highly weathered rock turns gray. [2] [4] It is fairly fissile, [6] [5] [7] breaking into thin, irregularly shaped sheets [10] or flakes [4] that occasionally display crystals of pickeringite. [2] Relieved of stress once exposed, the Cleveland Shale is nonplastic [4] and can appear as if fragmented into blocks due to jointing. [5]

Pyrite basal boundary

There is a sharp and clear distinction between the Cleveland Shale and underlying Chagrin Shale. [2] [10] At the very bottom of the Cleveland Shale there is a thin, discontinuous layer of pyrite. [5] [lower-alpha 2] This pyrite layer is discontinuous because after this rock was laid down, it was eroded. The erosion increases as one moves south along the valley of the Cuyahoga River and east to the Grand River. [7] Portions of the pyrite layer, known as Skinner's Run Bed, [7] contain fragments of petrified wood and fossilized fish bones worn smooth by the action of water. [5] Above the pyrite layer, a limestone layer is found in west-central (but not eastern) Ohio. [9]

The remainder of the Cleveland Shale generally consists of a relatively hard, [9] [lower-alpha 3] organic rich [12] oil shale. [4] [8] It has both an upper and lower part. [9]

Lower part

A clay shale, [9] described as bluish or bluish-gray [9] and as olive-black to brownish-black, [13] forms the lower part. The lower part can be anywhere from a few inches to several feet in thickness. This layer is sometimes referred to as the Olmstead shale. This layer has been dated to between 362.6 and 361.0 million years old based on conodont biozones (Bispathodus aculeatus aculeatus to Bispathodus ultimus ultimus zones). [14] [15] Thin beds of gray or brown siltstone, lumps of pyrite, and layers of silica-heavy limestone with cone-in-cone structures are found in the lower part. In eastern Ohio, thin gray veins ("stringers") of siltstone appear. [9] In western Ohio, [8] the Cleveland Shale appears to interbed with the Chagrin Shale below it, erasing the clear boundary between the two rock formations. [9]

Upper part

The upper part of the Cleveland Shale is a black to brownish black [13] silty shale [9] with occasional thin beds of gray shale and siltstone. [5] The upper part is much richer in petroleum [16] and kerogen. [4] [lower-alpha 4] When broken open, fresh samples smell like crude oil. [4] Where the upper part is thick, [7] and particularly in northeast Ohio, [10] the shale has a distinctive "rippled" appearance. [7] The upper 10 feet (3.0 m) of the Cleveland Shale contains abundant nodules of phosphate, nodules and bands (extremely thin beds) of pyrite, bands of calcisiltite, and lamination. [13] Almost no concretions are found in the upper part. [4]

Geographic extent

A thick sequence of the Cleveland Shale exposed on the north bank of the Rocky River in North Olmsted, Ohio. For scale, note the paleontologists just right of center at the base of the cliff. Cleveland Shale exposure at Fort Hill along Rocky River, Cleveland, OH.jpg
A thick sequence of the Cleveland Shale exposed on the north bank of the Rocky River in North Olmsted, Ohio. For scale, note the paleontologists just right of center at the base of the cliff.

The Cleveland Shale is a shale geologic formation in Ohio in the United States. The Cleveland Shale underlies much of northeast Ohio in beds of varying thickness.

In northeast Ohio, the member does not appear east of the Grand River. [7] Measurements taken in northeast Ohio show the Cleveland Shale to be 7 feet (2.1 m) [7] to 100 feet (30 m) thick. [9] It is thickest around the Rocky River north of Berea, Ohio, and thins to the east, west, and south. [9]

The Cleveland Shale is found in east-central Kentucky. In east-central Kentucky, the Cleveland Shale is more uniform in thickness, ranging from 41.4 to 50.1 feet (12.6 to 15.3 m), and increases in thickness toward the east. [13]

The unit is also present in West Virginia [17] and in southwest Virginia, [18] where it is mapped as the Cleveland Member of the Ohio Shale.

Stratigraphic setting

The Cleveland Shale (or Cleveland Member) is a sub-unit of the Ohio Shale Formation. [7] [19] The Chagrin Shale underlies the Cleveland Shale. [20] The Bedford Shale generally overlies the Cleveland Shale, with a sharp distinction between the two. In west-central Ohio, more than 150 feet (46 m) of Bedford Shale may lie above the Cleveland Shale. In places, red and grey shale may intertongue (interlock) with the Cleveland Shale extensively. In far eastern Ohio, the Bedford Shale thins by more than 125 feet (38 m). Where the Cussewago Shale is also present, the Bedford Shale is usually less than 25 feet (7.6 m) and may be locally absent. In some areas, the Cleveland Shale is described as overstepped [7] or unconformably overlaid gradationally by Berea Siltstone and sharply by Berea Sandstone. [10]

It is the regional equivalent of the Hangenberg Black Shale and the Bakken Shale. [21]

Fossils

Exceptional marine animal fossils are found in the formation. The Cleveland Shale is generally considered to be fossil-poor, but there are exceptions. The basal pyrite layer contains petrified wood and fossilized fish bones. [5] The lower part is famous for its extensive and well-preserved fossil Chondrichthyans (including Cladoselache ), Conodonts, Placodermi, [7] [5] and palaeoniscinoids ray-finned fishes. [22] The giant predatory placoderms Dunkleosteus terrelli, Gorgonichthys clarki , Gymnotrachelus hydei , Heintzichthys gouldii , and five subspecies (including the type specimen) of Titanichthys were all discovered in the Cleveland Shale. [23] The Cleveland Shale is classified as a konservatte-lagerstatten, which means it often preserves complete body fossils. Typical early shark preservation includes soft tissue outlines and impressions, fin rays, gill musculature, cartilage, and stomach contents. [24] Placoderms in the Cleveland Shale typically do not show any good soft-tissue preservation. [25]

Faunal list follows Carr and Jackson (2008) [26] and Carr 2018 [27]

Placodermi

GenusSpeciesNotesImages
Brontichthys B. clarki
Bungartius B. perissus
Callognathus C. regularis
Coccosteus C. cuyahogae
Diplognathus D. mirabilis
Dunkleosteus D. terrelli
Glyptaspis G. verrucosus
Gorgonichthys G. clarki
Gymnotrachelus G. hydei
Heintzichthys H. gouldii
Holdenius H. holdeni
Hussakofia H. minor
Hlavinichthys H. jacksoni
Mylostoma M. eurhinus

M. newberryi

M. variabilis

May all be synonyms of M. variabilis
Paramylostoma P. arcualis
Selenosteus S. brevis
Steneosteus S. angustopectus

S. glaber

Titanichthys T. agassizi

T. attenuatus

T. clarkii

T. hussakofi

T. rectus

May all be synonyms of T. agassizi
Trachosteus T. clarki

Chondrichthyes

GenusSpeciesNotes
Cladoselache C. acanthopterygius

C. brachypterygius

C. clarki

C. desmopterygius

C. fyleri

C. magnificus

C. newberryi

Some species may be synonymous
Ctenacanthus C. concinnus

C. terrelli

C. tumidus

C. vetustus?

Some species may be synonymous
Diademodus D. hydei
Monocladodus M. sp.
Orodus O. spp. (x3)
Phoebodus P. politus
Stethacanthus S. altonensis

S. carinatus

Tamiobatis T. vetustus

T. cf. T. vetustus

Osteichthyans

GenusSpeciesNotes
Kentuckia K. hlaviniAdditional species may be present
Proceratodus P. wagneriOnly sarcopterygian currently recorded from the Cleveland Member
Tegeolepis T. clarki

Age

The Cleveland Shale is approximately 362.6 to 360.1 million years old, daing to the very latest part of the Devonian period, the Fammenian, [14] based on biostratigraphy from conodonts [15] and plant spores. [28] The Cleveland Shale extends all the way to the Hangenberg mass extinction that ended the Devonian but does not reach the very end of the Devonian period. Unlike the Permian-Triassic extinction and Cretaceous-Paleogene extinction the Devonian-Carboniferous boundary does not correlate with the mass extinction event at the end of this period. The Bedford Shale and Berea Sandstone represent Devonian layers that post-date the Devonian-Carboniferous extinction but were deposited on top of the Cleveland Shale, and encompass some of the recovery fauna otherwise typical of the Carboniferous in the aftermath of the Hangenberg Event. [29]

The upper 2.5 m of the Cleveland Shale has been chemostratigraphically correlated with the Hangenberg Event and the type stratigraphy in Germany, suggesting that the Cleveland Shale preserves the second of the two mass extinction events that together comprise the late Devonian extinction [30]

Interpretation of depositional environments

The Cleveland Shale is likely the regional expression of the Dasberg Event, a major extinction event that occurred near the end of the Devonian period. The Cleveland Shale is interpreted as having accumulated in an anaerobic environment. [6] Evidence exists to suggest that the Cleveland Shale was laid down during the Dasberg event, an Upper Famennian extinction event that devastated land-based flora and marine-based fauna. This led to a significant drop in marine oxygen (an anoxic event) and atmospheric carbon dioxide, and then a brief glaciation. The global environment recovered, only to suffer another extinction, the Hangenberg event, close to the Devonian-Carboniferous boundary. [31] While the Cleveland Shale was being deposited, extensive organic matter from the land was swept into the sea then lying over Ohio. [32] Although there is dispute over how deep this sea was, the Dasberg event meant that oceans could support few to no bottom-dwelling animals. This explains why the Cleveland Shale largely lacks fossils of benthic organisms [33] and has a high carbon content that colors the shale very dark gray to black. [5] [34]

The contact between the Chagrin Shale and Cleveland Shale has been described as interbedding. This feature is interpreted as having been caused when two different depositional environments (in this case, the oxygenated sea which laid down the Chagrin Shale and the anaerobic sea rich in organic matter which laid down the Cleveland Shale) moved repeatedly back and forth over the same area. [9] Geologist Horace R. Collins called the boundary area intercalated, [8] but it is unclear what meaning he intended. [lower-alpha 5]

Different hypotheses have been suggested as the cause of the regional, irregular contact between the Cleveland Shale and Bedford Formation. Charles E.B. Conybeare has noted that the Cleveland Shale is siltier in the east and more calcareous in the west. He hypothesized that this indicates that silt flowed into the sea from east to west. Current eroded the Cleveland Shale and then laid down new sediment in the gullies which became the Bedford Formation. [34] Jack C. Pashin and Frank R. Ettensohn proposed a variation on this hypothesis. They note that the region containing the Cleveland Shale was undergoing uplift when the Bedford Formation was being deposited. This likely led to exposure and erosion of the Cleveland Shale, with sediment which became the Bedford Formation filling in these gullies. They also observe that there is evidence of diapirism (the intrusion of deformable Cleveland Shale upward into the more brittle Bedford Formation), as well as intertonguing. [37] Baird et al. note that the Cleveland Shale also tilts downward to the south. They suggest that this caused overstepping, rather than intertonguing. [7]

Economic geology

The high organic content of the Cleveland Shale makes it eminently suitable for the formation of fossil fuels. One 1981 study found that the Cleveland Shale can yield an average of 14 US gallons (53 L; 12 imp gal) of petroleum per 1 short ton (0.91 t) of rock. [38] The Cleveland Shale also contains cannel coal and "true" coal, although neither in great quantity. [4]

See also

Related Research Articles

<span class="mw-page-title-main">Late Devonian extinction</span> One of the five most severe extinction events in the history of the Earths biota

The Late Devonian extinction consisted of several extinction events in the Late Devonian Epoch, which collectively represent one of the five largest mass extinction events in the history of life on Earth. The term primarily refers to a major extinction, the Kellwasser event, also known as the Frasnian-Famennian extinction, which occurred around 372 million years ago, at the boundary between the Frasnian stage and the Famennian stage, the last stage in the Devonian Period. Overall, 19% of all families and 50% of all genera became extinct. A second mass extinction called the Hangenberg event, also known as the end-Devonian extinction, occurred 359 million years ago, bringing an end to the Famennian and Devonian, as the world transitioned into the Carboniferous Period.

<span class="mw-page-title-main">Chagrin River</span> River in Ohio, United States

The Chagrin River is located in Northeast Ohio. The river has two branches, the Aurora Branch and East Branch. Of three hypotheses as to the origin of the name, the most probable is that it is a corruption of the name of a Frenchman, Sieur de Seguin, who established a trading post on the river ca. 1742. The Chagrin River runs through suburban areas of Greater Cleveland in Cuyahoga, Geauga, and Portage counties, transects two Cleveland Metroparks reservations, and then meanders into nearby Lake County before emptying into Lake Erie.

The Famennian is the later of two faunal stages in the Late Devonian epoch. The most recent estimate for its duration is that it lasted from around 371.1 to 359.3 million years ago. An earlier 2012 estimate, still used by the International Commission on Stratigraphy, is that it lasted from 372.2 million years ago to 358.9 million years ago. It was preceded by the Frasnian stage and followed by the Tournaisian stage.

Gildersleeve Mountain is a summit located in Kirtland, Ohio, United States.

The Hangenberg event, also known as the Hangenberg crisis or end-Devonian extinction, is a mass extinction that occurred at the end of the Famennian stage, the last stage in the Devonian Period. It is usually considered the second-largest extinction in the Devonian Period, having occurred approximately 13 million years after the Late Devonian mass extinction at the Frasnian-Famennian boundary. The event is named after the Hangenberg Shale, which is part of a sequence that straddles the Devonian-Carboniferous boundary in the Rhenish Massif of Germany.

<span class="mw-page-title-main">Hamilton Group</span> Geological Group in North America

The Hamilton Group is a Devonian-age geological group which is located in the Appalachian region of the United States. It is present in New York, Pennsylvania, Maryland, Ohio, West Virginia, northwestern Virginia and Ontario, Canada, and is mainly composed of marine shale with some sandstone.

<span class="mw-page-title-main">Marcellus Formation</span> Middle Devonian age unit of sedimentary rock

The Marcellus Formation or the Marcellus Shale is a Middle Devonian age unit of sedimentary rock found in eastern North America. Named for a distinctive outcrop near the village of Marcellus, New York, in the United States, it extends throughout much of the Appalachian Basin.

<span class="mw-page-title-main">Bedford Shale</span> Geological formation in the United States

The Bedford Shale is a shale geologic formation in the states of Ohio, Michigan, Pennsylvania, Kentucky, West Virginia, and Virginia in the United States.

The Exshaw Formation is a stratigraphic unit in the Western Canada Sedimentary Basin. It takes the name from the hamlet of Exshaw, Alberta in the Canadian Rockies, and was first described from outcrops on the banks of Jura Creek north of Exshaw by P.S. Warren in 1937. The formation is of Late Devonian to Early Mississippian age as determined by conodont biostratigraphy, and it straddles the Devonian-Carboniferous boundary.

<span class="mw-page-title-main">New Albany Shale</span>

The New Albany Shale is an organic-rich geologic formation of Devonian and Mississippian age in the Illinois Basin of the United States. It is a major source of hydrocarbons.

<span class="mw-page-title-main">Berea Sandstone</span> Sandstone formation in the United States

Berea Sandstone, also known as Berea Grit, is a sandstone formation in the U.S. states of Michigan, Ohio, Pennsylvania, West Virginia, and Kentucky. It is named after Berea, Ohio. The sandstone has been used as a building stone and is a source of oil and gas.

<span class="mw-page-title-main">Borden Formation</span> Mississippian period geologic formation in Appalachia and Midwest United States

The Mississippian 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 rather than a formation.

<span class="mw-page-title-main">Waverly Group</span> Geologic group in the United States

The Waverly Group is a geologic group in Michigan and Ohio. It preserves fossils dating back to the Carboniferous period.

<span class="mw-page-title-main">Chagrin Shale</span> Geological formation in the United States

The Chagrin Shale is a shale geologic formation in the eastern United States that is approximately 365 million years old. The Chagrin Shale is a gray shale that begins thin and deep underground in north-central Ohio. As it proceeds east, the formation thickens, rises to the surface, and contains greater amounts of siltstone.

<span class="mw-page-title-main">Chattanooga Shale</span> Devonian era geologic formation in Appalachian and Southern United States

The Chattanooga Shale is a geological formation in Alabama, Arkansas, Georgia, Kentucky, Missouri and Tennessee. It preserves conodont fossils dating to the Devonian period. It occurs mostly as a subsurface geologic formation composed of layers of shale. It is located in East Tennessee and also extends into southeastern Kentucky, northwestern Georgia, and northern Alabama. This part of Alabama is part of the Black Warrior Basin.

The Pennington Formation is a geologic formation named for Pennington Gap, Virginia. It can be found in outcrops along Pine Mountain and Cumberland Mountain in Kentucky, Virginia, and Tennessee, where it is the uppermost Mississippian-age formation. The name has also been applied to similar Mississippian strata in the Cumberland Escarpment of eastern Kentucky, though the rocks in that area were later renamed to the Paragon Formation.

The Kettle Point Formation, also known as the Kettle Point (black) Shale, is a geologic formation that consists of thinly laminated, siliciclastic, organic-rich black shale with thin to thick interbeds of organic-poor mudstone. It is largely restricted to the subsurface of southwestern Ontario.

The geology of Ohio formed beginning more than one billion years ago in the Proterozoic eon of the Precambrian. The igneous and metamorphic crystalline basement rock is poorly understood except through deep boreholes and does not outcrop at the surface. The basement rock is divided between the Grenville Province and Superior Province. When the Grenville Province crust collided with Proto-North America, it launched the Grenville orogeny, a major mountain building event. The Grenville mountains eroded, filling in rift basins and Ohio was flooded and periodically exposed as dry land throughout the Paleozoic. In addition to marine carbonates such as limestone and dolomite, large deposits of shale and sandstone formed as subsequent mountain building events such as the Taconic orogeny and Acadian orogeny led to additional sediment deposition. Ohio transitioned to dryland conditions in the Pennsylvanian, forming large coal swamps and the region has been dryland ever since. Until the Pleistocene glaciations erased these features, the landscape was cut with deep stream valleys, which scoured away hundreds of meters of rock leaving little trace of geologic history in the Mesozoic and Cenozoic.

<span class="mw-page-title-main">Geology of South Dakota</span>

The geology of South Dakota began to form more than 2.5 billion years ago in the Archean eon of the Precambrian. Igneous crystalline basement rock continued to emplace through the Proterozoic, interspersed with sediments and volcanic materials. Large limestone and shale deposits formed during the Paleozoic, during prevalent shallow marine conditions, followed by red beds during terrestrial conditions in the Triassic. The Western Interior Seaway flooded the region, creating vast shale, chalk and coal beds in the Cretaceous as the Laramide orogeny began to form the Rocky Mountains. The Black Hills were uplifted in the early Cenozoic, followed by long-running periods of erosion, sediment deposition and volcanic ash fall, forming the Badlands and storing marine and mammal fossils. Much of the state's landscape was reworked during several phases of glaciation in the Pleistocene. South Dakota has extensive mineral resources in the Black Hills and some oil and gas extraction in the Williston Basin. The Homestake Mine, active until 2002, was a major gold mine that reached up to 8000 feet underground and is now used for dark matter and neutrino research.

The geology of Kentucky formed beginning more than one billion years ago, in the Proterozoic eon of the Precambrian. The oldest igneous and metamorphic crystalline basement rock is part of the Grenville Province, a small continent that collided with the early North American continent. The beginning of the Paleozoic is poorly attested and the oldest rocks in Kentucky, outcropping at the surface, are from the Ordovician. Throughout the Paleozoic, shallow seas covered the area, depositing marine sedimentary rocks such as limestone, dolomite and shale, as well as large numbers of fossils. By the Mississippian and the Pennsylvanian, massive coal swamps formed and generated the two large coal fields and the oil and gas which have played an important role in the state's economy. With interludes of terrestrial conditions, shallow marine conditions persisted throughout the Mesozoic and well into the Cenozoic. Unlike neighboring states, Kentucky was not significantly impacted by the Pleistocene glaciations. The state has extensive natural resources, including coal, oil and gas, sand, clay, fluorspar, limestone, dolomite and gravel. Kentucky is unique as the first state to be fully geologically mapped.

References

Notes
  1. Quartz particles in the shale range from 2 to 7 micrometres (7.9×10−5 to 0.000276 in) in size. [4]
  2. Pyrite forms when organic material falls onto an ocean floor that is anaerobic, has little bottom current, and has extensive deposition of silt and sediment. [7]
  3. "Hard" is defined as having a compressive strength between 10,000 to 13,000 pounds per square inch (69,000 to 90,000 kPa). [11]
  4. In a 1981 study of Cleveland Shale samples in central-eastern Kentucky, the upper part of the shale was 11 percent carbon and 1.3 percent hydrogen. [16]
  5. Intercalation can be used as a synonym for interbedding. [35] The term may also mean the introduction of a new layer between two preexisting layers. [36]
Citations
  1. 1 2 Wilmarth 1938, p. 361.
  2. 1 2 3 4 5 Williams 1940, p. 19.
  3. "National Geologic Map Database".
  4. 1 2 3 4 5 6 7 8 9 10 11 12 Johnson 1981, p. 171.
  5. 1 2 3 4 5 6 7 8 9 Hannibal & Feldman 1987, p. 404.
  6. 1 2 3 Pashin & Ettensohn 1995, p. 57.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 13 Baird et al. 2009, p. 10.
  8. 1 2 3 4 Collins 1979, p. E-10.
  9. 1 2 3 4 5 6 7 8 9 10 11 12 13 Pepper, DeWitt & Demarest 1954, p. 16.
  10. 1 2 3 4 Pashin & Ettensohn 1995, p. 51.
  11. Vyas, Aho & Robl 1981, p. 390.
  12. Pashin & Ettensohn 1995, p. 50.
  13. 1 2 3 4 Pollock, Barron & Beard 1981, p. 204.
  14. 1 2 Becker, R.T.; Marshall, J.E.A.; Da Silva, A.-C.; Agterberg, F.P.; Gradstein, F.M.; Ogg, J.G. (2020). "The Devonian Period". Geologic Time Scale 2020: 733–810. doi:10.1016/B978-0-12-824360-2.00022-X. ISBN   9780128243602. S2CID   241766371.
  15. 1 2 Zagger, Glenn W. (1995). Conodont biostratigraphy and sedimentology of the latest Devonian of northeast Ohio (Thesis). Case Western Reserve University. p. 112.
  16. 1 2 Bland, Robl & Koppenaal 1981, p. 188.
  17. Ryder, R.T., Swezey, C.S., Crangle, R.D., Jr., and Trippi, M.T., 2008, Geologic cross section E-E' through the central Appalachian Basin from the Findlay Arch, Wood County, Ohio, to the Valley and Ridge Province, Pendleton County, West Virginia: U.S. Geological Survey Scientific Investigations Map SIM-2985, 2 sheets with 48-page pamphlet. http://pubs.er.usgs.gov/publication/sim2985
  18. Ryder, R.T., Trippi, M.H., and Swezey, C.S., 2015, Geologic cross section I-I' through the central Appalachian basin from north-central Kentucky to southwestern Virginia: U.S. Geological Survey Scientific Investigations Map SIM-3343, 2 sheets with two pamphlets (41p. and 102p.). http://pubs.er.usgs.gov/publication/sim3343
  19. Rubel & Coburn 1981, p. 22.
  20. Pashin & Ettensohn 1995, p. 6.
  21. Kaiser, Aretz & Becker 2016, p. 404.
  22. Hansen 2005, pp. 292–293.
  23. Hansen 2005, pp. 290.
  24. Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database" . Retrieved 17 December 2021.
  25. Carr, Robert K. (2010). "Paleoecology of Dunkleosteus terrelli (Placodermi: Arthrodira)". Kirtlandia. 57: 36–45.
  26. Carr, Robert K.; Jackson, Gary L. "The vertebrate fauna of the Cleveland Member (Famennian) of the Ohio Shale". Guide to the Geology and Paleontology of the Cleveland Member of the Ohio Shale (68th Annual Meeting of the Society of Vertebrate Paleontology, Cleveland, Ohio.: 1–187.
  27. Carr, Robert K. (30 September 2018). "A new aspinothoracid arthrodire from the Late Devonian of Ohio, U.S.A." Acta Geologica Polonica. 68 (3): 363–379. doi:10.1515/agp-2018-0021 (inactive 31 January 2024).{{cite journal}}: CS1 maint: DOI inactive as of January 2024 (link)
  28. Eames, Leonard Eugene (1974). Palynology of the Berea Sandstone and Cuyahoga Group of northeastern Ohio (Thesis). East Lansing: Michigan State University. p. 210.
  29. Dixson, Sara P.; Shope, Dakota P. (2018). A Diminutive Late Devonian Recovery Fauna from the Cleveland Shale. Geological Society of America Southeast Sectional Meeting. Charleston, South Carolina.
  30. Martinez, Aaron M.; Boyer, Diana L.; Droser, Mary L.; Barrie, Craig; Love, Gordon D. (24 September 2018). "A stable and productive marine microbial community was sustained through the end-Devonian Hangenberg Crisis within the Cleveland Shale of the Appalachian Basin, United States". Geobiology. 17 (1): 27–42. doi: 10.1111/gbi.12314 . PMID   30248226. S2CID   52811336.
  31. Baird et al. 2009, pp. 8, 10.
  32. Kaiser, Aretz & Becker 2016, p. 415.
  33. Hannibal & Feldman 1987, p. 406.
  34. 1 2 Conybeare 1979, pp. 419–420.
  35. Bates & Jackson 1984, p. 262.
  36. Neuendorf, Mehl & Jackson 2005, p. 330.
  37. Pashin & Ettensohn 1995, pp. 50–51.
  38. Reasoner et al. 1981, p. 12.

Bibliography