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 United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

. 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 ...

dating back to the

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

period.

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 (Pelecaniformes: 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