The St. Louis Limestone is a large

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 ...

covering a wide area of the midwest of the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. It is named after an exposure at

St. Louis, Missouri St. Louis ( , sometimes referred to as St. Louis City, Saint Louis or STL) is an Independent city (United States), independent city in the U.S. state of Missouri. It lies near the confluence of the Mississippi River, Mississippi and the Miss ...

. It consists of sedimentary

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

with scattered

chert Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a prec ...

beds, including the heavily chertified

Lost River Chert Bed Lost or LOST may refer to getting lost, or to: Arts, entertainment, and media Television * ''Lost'' (TV series), a 2004 American drama series about people who become stranded on a mysterious island * ''Lost'' (2001 TV series), a short-lived Ameri ...

in the

Horse Cave Member The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million ...

. It is exposed at the surface through western

Kentucky Kentucky (, ), officially the Commonwealth of Kentucky, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Illinois, Indiana, and Ohio to the north, West Virginia to the ...

and

Middle Tennessee Middle Tennessee is one of the three Grand Divisions of Tennessee that composes roughly the central portion of the state. It is delineated according to state law as 41 of the state's 95 counties. Middle Tennessee contains the state's capital an ...

, including the city of

Clarksville, Tennessee Clarksville is a city in Montgomery County, Tennessee, United States, and its county seat. The city had a population of 166,722 as of the 2020 United States census, 2020 census, making it the List of municipalities in Tennessee, fifth-most populo ...

. The limestone deposit is

Mississippian Mississippian may refer to: * Mississippian (geology), a subperiod of the Carboniferous period in the geologic timescale, roughly 360 to 325 million years ago * Mississippian cultures, a network of precontact cultures across the midwest and Easte ...

in age, in the

Meramecian The Meramecian or Maramec stage is a sequence of Mississippian rocks in the Mississippi River Valley. It is named for the Meramec River in Missouri. Members Included are the St. Louis Limestone, Ste. Genevieve Limestone, Salem Limestone, and the ...

series, roughly 330-340 million years old. Fossils commonly found in the St. Louis include the

rugosa The Rugosa or rugose corals are an extinct Class (biology), class of solitary and Colony (biology), colonial corals that were abundant in Middle Ordovician to Late Permian seas. Solitary rugosans (e.g., ''Caninia (genus), Caninia'', ''Lopho ...

n corals ''

Lithostrotion ''Lithostrotion'' is a genus of rugose coral which is commonly found as a fossil within Carboniferous Limestone. ''Lithostrotion'' is a member of the family Lithostrotionidae. The genus ''Lithostrotion'', a common and readily recognised group ...

'' and '' Lithostrotionella'' and the bryozoan '' Fenestrellina''.

References

Limestone formations of the United States Mississippian United States Carboniferous Kentucky Mississippian Missouri Carboniferous geology of Virginia Carboniferous Tennessee Mississippian Illinois Carboniferous southern paleotropical deposits Shale formations of the United States Chert formations {{US-geologic-formation-stub

See also

References