| Cowlitz Formation | |
|---|---|
| Stratigraphic range: Paleogene | |
| Type | Formation |
| Underlies | Keasey Formation |
| Location | |
| Region | Clatsop County, Oregon Lewis County, Washington (state) |
| Country |  United States |
The Cowlitz Formation is a geologic formation in Washington (state). It preserves fossils dating back to the Paleogene period
The Cowlitz Formation holds fossils dating back to the Paleogene period. 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 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:
The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in the dry season. Each pair of layers is called a varve and represents one year. The sediments of the Green River Formation present a continuous record of six million years. The mean thickness of a varve here is 0.18 mm, with a minimum thickness of 0.014 mm and maximum of 9.8 mm.
The Piney Point Formation is a geologic formation in Virginia. It preserves fossils dating back to the Lutetian Stage of the Eocene Epoch of the Paleogene period.
The Wilcox Formation is a geologic formation in Tennessee. It preserves fossils dating back to the Paleogene period.
The Alum Bluff Group is a geologic group in the states of Georgia, Florida, and Alabama. It preserves fossils dating back to the Neogene period.
The Tallahatta Formation is a geologic formation found on the surface in Alabama, Florida, Georgia, and Mississippi. It is also located in the subsurface of Kentucky. The Tallahatta formation is part of the Claiborne Group and contains four members: the Basic City Shale in Mississippi, the Holy Springs Sand Member in Mississippi, the Meridian Sand Member in Alabama and Mississippi, and the Neshoba Sand Member in Mississippi. It preserves fossils dating back to the Paleogene period, specifically the Eocene.
The Hatchetigbee Bluff Formation is a geologic formation in Alabama, Georgia, Louisiana and Mississippi. The youngest unit of the Wilcox Group preserves fossils dating back to the Ypresian stage of the Eocene period, or Wasatchian in the NALMA classification. The formation is named for Hatchetigbee Bluff on the Tombigbee River, Washington County, Alabama.
The Weches Formation is a greensand, slay, and shale geologic formation in Louisiana and Eastern Texas. It preserves fossils dating back to the Paleogene period, specifically the Eocene.
The White River Formation is a geologic formation of the Paleogene Period, in the northern Great Plains and central Rocky Mountains, within the United States.
The Stone City Formation is a geologic formation in Texas. It preserves fossils dating back to the Paleogene period. Now known as Stone City Bluff in Burleson County, Texas, it is a special location on the Texas Gulf Coast Plain. It is the best of relatively few places where marine rocks of Paleogene age are exposed and available for public access. This access provides a window into Middle Eocene rocks that were deposited in the Gulf of Mexico approximately 41.8 million years ago.
The Hoback Formation is a geologic formation in west-central Wyoming, located within the Hoback Basin. It formed as a result of increased sedimentation rates from the Laramide Orogeny and preserves fossils dating back to the late Paleogene period, through the early Eocene.
The Keasey Formation is a geologic formation in northwestern Oregon. It preserves fossils dating back to the Paleogene period.
The Townsend Shale is a geologic formation in Washington (state). It preserves fossils dating back to the Paleogene period.
The Mulholland Formation is a Pliocene epoch geologic formation in the Berkeley Hills and San Leandro Hills of the East Bay region of the San Francisco Bay Area, California. It is found within Alameda County and Contra Costa County.
The La Jolla Group is a group of geologic formations in coastal southwestern San Diego County, Southern California. Its locations include the coastal La Jolla San Diego region.
The Mission Valley Formation is a marine sandstone geologic formation in the Mission Valley region of southwestern San Diego County in Southern California.
The Pomerado Conglomerate Formation is a geologic formation in southwestern San Diego County, California.
The Santa Susana Formation is a Paleogene period geologic formation in the Simi Hills and western Santa Susana Mountains of southern California.
The Scripps Formation is a geologic formation in coastal San Diego County, California.
The Stadium Conglomerate is a geologic formation in San Diego County, California. It is found at the northern end of Mission Valley near San Diego Stadium.
The Eureka Sound Formation is a geologic formation found in the Canadian Territory of Nunavut on Ellesmere Island, which is part of the Canadian Arctic Archipelago. The Eureka Sound Formation is Tertiary in age.
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