The Word Formation is a geologic formation in Texas.[1] It preserves fossils dating back to the Permian period. It is probably named for the Old Word Ranch in the Glass Mountains of Brewster County.[2]

Word Formation
Stratigraphic range: Roadian-Wordian
~272–265.1 Ma
Fossil from the Word Formation
TypeFormation
Sub-unitsAppel Ranch, China Tank & Willis Ranch members
OverliesRoad Canyon Formation
Lithology
PrimaryLimestone
Location
Coordinates30°24′N 103°12′W / 30.4°N 103.2°W / 30.4; -103.2
Approximate paleocoordinates1°36′N 33°00′W / 1.6°N 33.0°W / 1.6; -33.0
RegionTexas
Country United States
ExtentGlass Mountains
Type section
Named forOld Word Ranch
Word Formation is located in the United States
Word Formation
Word Formation (the United States)
Word Formation is located in Texas
Word Formation
Word Formation (Texas)

Defining formation

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The Wordian age of the Permian Period is named for the Word Formation.[3]

Subdivisions

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The formation is subdivided into three members, from young to old:

  • Appel Ranch - Wordian[4]
  • China Tank - Roadian[5]
  • Willis Ranch - Roadian[6]

Fossil content

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The limestone formation contains marine gastropods, brachiopods and ammonites.[1]

Vertebrate paleofauna

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See also

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References

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Further reading

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  • M. Kelly and R. Zangerl. 1976. Helicoprion (Edestidae) in the Permian of West Texas. Journal of Paleontology 50(5):992-994
  • G. A. Cooper and R. E. Grant. 1972. Permian brachiopods of west Texas, I. Smithsonian Contributions to Paleobiology 14:1-231
  • R. L. Batten. 1958. Permian Gastropoda of the southwestern United States. 2. Pleurotomariacea: Portlockiellidae, Phymatopleuridae, and Eotomariidae. Bulletin of the American Museum of Natural History 114(2):153-246
  • E. L. Yochelson. 1956. Permian Gastropoda of the southwestern United States. 1. Euomphalacea, Trochonematacea, Pesudophoracea, Anomphalacea, Craspedostomatacea, and Platyceratacea. Bulletin of the American Museum of Natural History 110(3):173-276
  • A. K. Miller and W. M. Furnish. 1940. Permian ammonoids of the Guadalupe Mountain region and adjacent area. Geological Society of America Special Paper 26:1-242
  • F. B. Plummer and G. Scott. 1937. Upper Paleozoic ammonites in Texas. The University of Texas Bulletin 3701:1-516
  • R. E. King. 1931. The Geology of the Glass Mountains, Texas, Part II, Faunal summary and correlation of the Permian formations with description of Brachiopoda. The University of Texas Bulletin 3042:1-245
  • G. H. Girty. 1909. The Guadalupian fauna. United States Geological Survey Professional Paper 58:1-651