The Cowlitz 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
Washington (state)
Washington, officially the State of Washington, is a U.S. state, state in the Pacific Northwest region of the United States. It is often referred to as Washington State to distinguish it from Washington, D.C., the national capital, both n ...
. 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
Period may refer to:
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* Period (punctuation)
* Era, a length or span of time
*Menstruation, commonly referred to as a "period"
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Findings
The Cowlitz Formation holds fossils dating back to the
Paleogene period
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 ...
. These fossils were discovered in 1911 through the work of Charles E. Weaver, Charles R. Fettkc,
Donald Ross, T. A. Bonser, and Olaf Stromme in their task to study more closely the Tertiary Paleontology of Western Washington. Along with the Cowlitz Formation, they also closely observed the
Tejon Formation. These two formations are a part of a greater Eocene of Western Washington. The basaltic lavas and tuffs occurring within the Eocene of western Washington have a thickness ranging from fifteen hundred to two thousand feet.
The Cowlitz Formation is located in the canyon of Olequa Creek between towns of
Winlock and
Olequa, in southwestern
Lewis Co., and northwestern
Cowlitz Co., WA.
The rocks composing this formation are sandstones, shales, conglomerates and subordinate amount of shaly limestone, together with numerous intercalated layers of tuff and basaltic lava. They arc partly marine and partly brackish water deposits.
A total Tertiary invertebrate marine
fauna
Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...
of forty five was discovered. Thirty of these were new and had been discovered for the first time. The Cowlitz Formation contained the following fauna:
* Pelecypoda
*
Gasteropeda
*
Brachyopoda
* Shark's Teeth
See also
*
*
Paleontology in Washington (state)
Paleontology in Washington encompasses Paleontology, paleontological research occurring within or conducted by people from the United States, U.S. state of Washington (state), Washington. Washington has a rich fossil Fossil record, record spanning ...
References
*
Paleogene geology of Washington (state)
Paleogene geology of Oregon
Formations
Formations
Geologic formations of Washington (state)
Geologic formations of Oregon
{{Paleogene-stub