The Ogallala Formation is a Miocene to early Pliocene geologic formation in the central High Plains of the western United States and the location of the Ogallala Aquifer. In Nebraska and South Dakota it is also classified as the Ogallala Group. Notably, it records the North American Land Mammal Ages (NALMAs) Hemphillian, Clarendonian, and Barstovian. It also includes an excellent record of grass seeds and other plant seeds, which can be used for biostratigraphic dating within the formation. The Ogallala Formation outcrops of Lake Meredith National Recreation Area preserve fish fossils. Similar specimens from the same unit are found at Alibates Flint Quarries National Monument in Texas.
The Stanton Formation is a geologic formation of limestone in Iowa, Nebraska, Missouri and Kansas. It preserves fossils dating back to the Carboniferous period. It is in the Upper Pennsylvanian series, forming the top of the Lansing Group.
The Council Grove Group is a geologic group in Kansas, Oklahoma, and Nebraska as well as subsurface Colorado. It preserves fossils dating to the Carboniferous-Permian boundary. This group forms the foundations and lower ranges of the Flint Hills of Kansas, underlying the Chase Group that forms the highest ridges of the Flint Hills.
The Wabaunsee Group is a Late-Carboniferous geologic group in Kansas, extending into Nebraska, Iowa, Missouri, and Oklahoma. The unit is recognized in the subsurface by drillers in Colorado as Wabaunsee Formation.
The Americus Limestone is a member of the Foraker Limestone Formation in eastern Kansas, where it is quarried as a distinctive ornamental stone. In outcrop, it is typically recognized as two relatively thin but persistent beds of hard limestone separated by shale that forms the lowest prominent bench of the many benches of the Flint Hills. The recognizable facie of the member in excavated or eroded exposures is two thin limestone beds separated a bed of shale and adjacent shales above and below having a particular gray or bluish color darker than higher limestones. A third, lower, highly variable algal limestone is often present and included as the base of the member. The unit is not particularly massive, the limestone pair totaling 3 to 4 feet in places, more in other locations but less to the North, and up to nearly to 9 feet at the type location of Americus, Kansas. The addition of the lower algal limestone as a base for the unit increases the thickness to over 18 feet. Initially thought to be the lowest of the Permian rock of Kansas and as such classified as the lowest unit of the Council Grove Group, the unit is now dated within the uppermost Late Carboniferous.
The Emporia Formation, also referred to as Emporia Limestone, is a Late-Carboniferous geologic formation in Kansas, extending into Nebraska, Iowa, Missouri, and Oklahoma.
The Tarkio Limestone, is a Late-Carboniferous member of the Zeandale Formation in Kansas, extending into Nebraska, Iowa, and Missouri. The unit was named for outcrops in the Tarkio Valley in northwestern Missouri, however, R.C. Moore designated a typical exposure of this unit on Mill Creek, southwest of Maple Hill, Kansas. Owing to its unusual coloration, an early name for this rock was chocolate limestone. This rock can be recognized by its coloration and abundant fusulinids, Triticites ventricosus, protruding from the surfaces, giving a "raspy" texture.
The Wellington Formation is an Early Permian geologic formation in Kansas and Oklahoma. The formation's Hutchinson Salt Member is more recognized by the community than the formation itself, and the salt is still mined in central Kansas. The Wellington provides a rich record of Permian insects and its beddings provide evidence for reconstruction of tropical paleoclimates of the Icehouse Permian with the ability in cases to measure the passage of seasons. Tens of thousands of insect fossil recovered from the Wellington shales are kept in major collections at the Harvard Museum of Comparative Zoology and Yale Peabody Museum of Natural History.
The Eskridge Shale or Eskridge Formation is an Early Permian geologic formation in Kansas. Its outcrop runs north–south through Kansas, extending into Oklahoma and Nebraska. While named a shale, it features extensive, spectacular red and green stacked palosol mudstones, these mudstones showing prominent vertical tubular carbonate concretions, possibly from roots or vertebrate burrows.
The Foraker Formation is a geologic formation in Nebraska, Kansas, and Oklahoma. It preserves fossils dating to the Carboniferous period.
The Johnson Formation is a thick geologic formation of soft shale with thin, resistant beds of chalkier mudstone and limestone in Nebraska, Kansas, and Oklahoma rarely exposed outside of road cuts. It preserves fossils dating back to the late-Carboniferous period.
The Red Eagle Formation is a geologic formation ranging from Oklahoma, through Kansas, into southeast Nebraska of the United States. Its members define the Carboniferous-Permian boundary in Kansas.
The Grenola Formation is an early Permian geologic formation (Wolfcampian) with its exposure running north and south through Kansas and extending into Nebraska and Oklahoma, notably having the Neva Limestone member, which is a terrace-forming aquifer and historic Flint Hills building stone source secondary to the Cottonwood Limestone.
The Benton Shale is a geologic formation name historically used in Montana, Wyoming, North Dakota, South Dakota, Colorado, Kansas, and Nebraska. In the "mile high" plains in the center of the continent, the named layers preserve marine fossils from the Late Cretaceous Period. The term Benton Limestone has also been used to refer to the chalky portions of the strata, especially the beds of the strata presently classified as Greenhorn Limestone, particularly the Fencepost limestone.
Cottonwood Limestone, or simply the Cottonwood, is a stratigraphic unit and a historic stone resource in east-central Kansas, northeast-central Oklahoma, and southeastern Nebraska in the Midwestern United States. It is the lowest member of the Beattie Limestone formation and commonly outcrops within the deep valleys and on top of the scenic residual ridges of the Flint Hills.
The Florena Shale is a stratigraphic unit in east-central Kansas, northeast-central Oklahoma, and southeastern Nebraska in the Midwestern United States. It preserves fossils dating to the Permian period.
The Fort Hays Limestone is a member of the Niobrara Formation of the Colorado Group exposed in Colorado, Kansas, Nebraska, and South Dakota and is named for the bluffs near the old Fort Hays, a well-known landmark in western Kansas.
The Roca Formation is an early Permian geologic formation (Wolfcampian) with its exposure running north and south through Kansas and extending into Nebraska and Oklahoma, notably comprising varicolored black, brown, gray, green, red, and blue shales, mudstones, and limestone, some of which representing Permian paleosols.
Haskell Limestone is a geological unit name originating in Kansas and used in adjoining states. The Pennsylvanian period unit was named by R.C. Moore for the Haskell Institute in the southeast of Lawrence, Kansas in 1931. The name has been applied to various beds within this range, and assigned as a member variously to the Lawrence Formation, Cass Formation, and Stranger Formation, and significant legacy literature exists for each classification. These three formations now comprise the Douglas Group.
The Willard Formation, also referred to as Willard Shale, is a Late-Carboniferous geologic formation in Kansas, extending into Nebraska, Iowa, Missouri, and Oklahoma.
