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Coyote Butte Limestone

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Geologic formation in Oregon, US For the Coyote Buttes section in Arizona, see Navajo Sandstone.
Coyote Butte Limestone
Stratigraphic range: Sakmarian (Wolfcampian)-Kungurian
~296–273 Ma PreꞒ Ꞓ O S D C P T J K Pg N
TypeFormation
Lithology
PrimaryLimestone
OtherSandstone
Location
Coordinates43°58′N 119°44′W / 43.96°N 119.74°W / 43.96; -119.74
Approximate paleocoordinates17°54′N 38°48′W / 17.9°N 38.8°W / 17.9; -38.8
RegionCrook County, Oregon
Country United States
ExtentIsolated buttes (Coyote & Tuckers) south
and north (Triangulation Hill) of Grindstone & Twelvemile Creeks, Crook County, Oregon
Type section
Named forCoyote Butte
Named byMerriam & Berthiaume
Year defined1943
Coyote Butte Limestone is located in the United StatesCoyote Butte LimestoneCoyote Butte LimestoneCoyote Butte Limestone (the United States)Show map of the United StatesCoyote Butte Limestone is located in OregonCoyote Butte LimestoneCoyote Butte LimestoneCoyote Butte Limestone (Oregon)Show map of Oregon

The Coyote Butte Limestone (OR085) is a geologic formation in Oregon. It preserves fossils dating back to the Sakmarian to Kungurian stages of the Permian period, spanning an estimated 23 million years. The formation occurs in isolated buttes to the north; Triangulation Hill, and south; type locality and name giver Coyote Butte and Tuckers Butte, on either side of the Grindstone and Twelvemile Creeks in Crook County, Oregon.

Description

The Coyote Butte Formation was first defined by Merriam and Berthiaume in 1943. The formation crops out in isolated buttes (Coyote & Tuckers) south and north (Triangulation Hill) of the Grindstone and Twelvemile Creeks in Crook County, central Oregon. The formation comprises an uncommonly unaltered and well-exposed set of Permian shallow marine and reefal limestones in the tectonically complex Permian present-day Pacific margin of western North America.

The Coyote Butte Formation is represented by isolated limestone hills (0.1 to 2.0 square kilometres (0.039 to 0.772 sq mi) in area), of which most appear to have the same stratigraphic and biostratigraphic sequence and appear to be right-side-up. The resistant limestone blocks stand above the surrounding rocks of the "melange." The Coyote Butte Formation represents shallow-water carbonate-platform deposition and contains a varied faunal assemblage of corals, bryozoans, algae, fusulinids, brachiopods, crinoids, and conodonts.

"The Permian Coyote Butte Formation is dated by conodonts, fusulinids, and brachiopods as Aktastinian, Leonardian, and Roadian (stages of Furnish, 1973). The formation shows remarkable similarity in age, fauna, and sedimentation to the limestones near Quinn River Crossing, Nevada. The Paleozoic limestone blocks rest among oceanic-derived blocks that are probably early Mesozoic in age. To imply that the limestone belonged to the same tectonic-sedimentary package as the oceanic sediments (Dickinson and Thayer, 1978) seems precluded. The limestones contain volcaniclastic sand (Dickinson and Thayer, 1978, p. 152), indicating probable local presence of volcanics during deposition. Because the outcrops of the Coyote Butte Formation appear to all be stratigraphically right-side-up, the "melange" is not as chaotic as proposed by Dickinson and Thayer (1978); it has some order.

Also, it would be hard to imagine the Coyote Butte Formation as deposited as local limestone in a volcanic island chain and then admixed to the deformed oceanic sediments while maintaining its stratigraphic integrity.

It is easier to imagine the Coyote Butte Formation as being introduced as a late-stage structural event to deforming oceanic sediments in Mesozoic time. This implies that the other Paleozoic rocks would be similar late-stage introductions to the "melange." Whether the Coyote Butte Formation represents the remnants of a large olistostrome (gravity slide block) or thrust block or blocks that maintained stratigraphic integrity is difficult to resolve, given the poor exposures in the Coyote Butte area.

Because the Coyote Butte Formation is so similar to rocks found near Quinn River Crossing, it is suggestive that the rocks belong to a larger mass of shelfal limestones, parts of which are now found at several scattered localities."

Paleogeographic situation

The formation is dated to the Sakmarian to Kungurian stages of the Early to Middle Permian period, spanning an estimated 23 million years from 296 to 273 Ma. During these times, what is now central Oregon, was located at the edge of Pangea in the northern paleotemperate zone, at paleolatitudes of 16-18° North.

Climate

See also: Category:Permian northern paleotemperate deposits and Permian § Climate

Tectonics

See also: Category:Permian orogenies, Category:Permian impact craters, and Permian § Tectonics

The hinterland of the carbonate platform where the Coyote Butte Limestone was deposited, was formed by the Arizonan and Utahan arid landscapes of a Pangea starting to break up. This occurred before the Sonoma orogeny was active in western North America and during the Alleghanian orogeny in eastern Laurentia and western Europe.

The 23 million year deposition coincided with impact of the Clearwater West crater, dated at 286.2 ± 2.6 million years ago.

  • Paleogeography of the Early Permian, 280 Ma Paleogeography of the Early Permian, 280 Ma
  • Location of the Alleghanian mountain chains in the Carboniferous period, just before the Permian Location of the Alleghanian mountain chains in the Carboniferous period, just before the Permian
  • Clearwater Lakes in Quebec, the larger West crater dated to 286.2 ± 2.6 Ma Clearwater Lakes in Quebec, the larger West crater dated to 286.2 ± 2.6 Ma

Paleontological significance

See also: Category:Paleontology in Oregon and Paleontology in Oregon

The formation is the only discovered Paleozoic fossiliferous formation in the state of Oregon, and comprises an uncommonly unaltered and well-exposed set of Early to Mid Permian shallow marine and reefal limestones in the tectonically complex Permian present-day Pacific margin of western North America. The formation just predates Olson's Extinction; a mass extinction that occurred 273 million years ago in the early Guadalupian of the Permian period and which predated the Permian–Triassic extinction event.

Fossil content

See also: Category:Permian geology of Oregon

Among others, the following fossils have been reported from the formation:

Brachiopods

Trilobites

Cummingella belisama

Rostroconchia

Gastropods

Polyplacophora

Corals

Correlations

Geologic correlations

Faunal correlations

Main pages: Category:Cisuralian life and Category:Cisuralian synapsids of North America

See also

Sources

Notes

  1. Oklahoma, Texas, Brazil and Zambia
  2. Arizona, Colorado, New Mexico, Utah: Cutler Formation ; Kansas: Fort Riley, Chase Group ; Ohio: Greene Formation, Dunkard Group, Oklahoma: Clyde & Wellington Formations, Texas: Admiral, Belle Plains & Clyde Formations, Wichita Group

References

  1. ^ Wardlaw et al., 1982, p.15
  2. ^ Coyote Butte Formation at Fossilworks.org
  3. Coyote Butte Formation at USGS
  4. Wardlaw et al., 1982, p.14
  5. Merriam & Berthiaume, 1943
  6. ^ Wardlaw et al., 1982, p.13
  7. Bottomley et al., 1990
  8. Schmieder et al., 2014
  9. Sahney & Benton, 2008
  10. ^ Cooper, 1957
  11. ^ Hanger et al., 2000
  12. ^ Merriam, 1942
  13. John J. Stephens, Ophiacodon aus Ohio

Bibliography

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