The Keasey Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

in northwestern

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

. It preserves

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

dating back to the

Paleogene The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

References

* *

* T. Nyborg, B. Nyborg, A. Garassino and F. J. Vega. 2016. New occurrences of fossil Macrocheira (Brachyura, Inachidae) from the North Eastern Pacific. Paleontologia Mexicana 5(2):123-135 * B. J. Welton. 2016. A new dalatiid shark (Squaliformes: Daltaiidae) from the early Oligocene of Oregon and California, USA. Fossil Record 5:289-302 * B. J. Welton. 2013. A new archaic basking shark (Lamniformes, Cetorhinidae) from the Late Eocene of Western Oregon, USA, and description of the dentition, gill rakers and vertebrae of the recent basking shark Cetorhinus Maximus (Gunnerus). New Mexico Museum of Natural History and Science Bulletin 58:1-48 * J. L. Goedert. 1989. Giant late Eocene Marine birds (Pelicaniformes: Pelagornithidae) from northwestern Oregon. Journal of Paleontology 63(6):939-944 * J. L. Goedert. 1988. A new late Eocene species of Plotopteridae (Aves: Pelecaniformes) from northwestern Oregon. Proceedings of the California Academy of Sciences 45(6):97-102 * C. J. Hickman. 1976. Bathyal gastropods of the family Turridae in the Early Oligocene Keasey Formation in Oregon, with a review of some deep-water genera in the Paleocene of the Eastern Pacific. Bulletins of American Paleontology 70(292):1-119 * A. K. Miller and H. R. Downs. 1950. Tertiary nautiloids of the Americas: supplement. Journal of Paleontology 24:1-18 Geology of Oregon {{Paleogene-stub

References

Further reading