The Smoky Hill Chalk Member of the
Niobrara Chalk
The Niobrara Formation , also called the Niobrara Chalk, is a geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the Late Cretaceous. It is compose ...
formation
Formation may refer to:
Linguistics
* Back-formation, the process of creating a new lexeme by removing or affixes
* Word formation, the creation of a new word by adding affixes
Mathematics and science
* Cave formation or speleothem, a secondar ...
is a
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
conservation
Lagerstätte
A Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These for ...
, or
fossil
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 ...
rich geological formation, known primarily for its exceptionally well-preserved
marine reptile
Marine reptiles are reptiles which have become secondarily adapted for an aquatic or semiaquatic life in a marine environment.
The earliest marine reptile mesosaurus (not to be confused with mosasaurus), arose in the Permian period during the ...
s.
Named for the
Smoky Hill River
The Smoky Hill River is a river in the central Great Plains of North America, running through Colorado and Kansas.Smoky Hill River. (2009). In Encyclopædia Britannica. Retrieved July 22, 2009, from Encyclopædia Britannica Online: http://www.br ...
,
the Smoky Hill Chalk Member is the uppermost of the two structural units of the Niobrara Chalk.
It is underlain by the
Fort Hays Limestone Member
The Fort Hays Limestone is a Stratigraphic unit#Member, 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 wes ...
; and the
Pierre Shale
The Pierre Shale is a geologic formation or series in the Upper Cretaceous which occurs east of the Rocky Mountains in the Great Plains, from Pembina Valley in Canada to New Mexico.
The Pierre Shale was described by Meek and Hayden in 1862 in th ...
overlies the Smoky Hill Chalk.
The Smoky Hill Chalk
outcrop
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth.
Features
Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial ...
s in parts of northwest
Kansas
Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the ...
, its most famous localities for fossils, and in southeastern
Nebraska
Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the southwe ...
. Large well-known fossils excavated from the Smoky Hill Chalk include marine reptiles such as
plesiosaur
The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia.
Plesiosaurs first appeared ...
s, large
bony fish
Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilag ...
such as ''
Xiphactinus
''Xiphactinus'' (from Latin and Greek for " sword-ray") is an extinct genus of large (Shimada, Kenshu, and Michael J. Everhart. "Shark-bitten Xiphactinus audax (Teleostei: Ichthyodectiformes) from the Niobrara Chalk (Upper Cretaceous) of Kansas. ...
'',
mosasaur
Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Greek ' meaning 'lizard') comprise a group of extinct, large marine reptiles from the Late Cretaceous. Their first fossil remains were discovered in a limestone quarry at Maastricht on th ...
s, flying reptiles or
pterosaur
Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to ...
s (namely ''
Pteranodon
''Pteranodon'' (); from Ancient Greek (''pteron'', "wing") and (''anodon'', "toothless") is a genus of pterosaur that included some of the largest known flying reptiles, with ''P. longiceps'' having a wingspan of . They lived during the late Cr ...
''), flightless marine birds such as ''
Hesperornis
''Hesperornis'' (meaning "western bird") is a genus of cormorant-like bird that spanned the first half of the Campanian age of the Late Cretaceous period (83.5–78 mya). One of the lesser-known discoveries of the paleontologist O. C. Marsh in ...
'', and
turtle
Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...
s. Many of the most well-known specimens of the marine reptiles were collected by dinosaur hunter
Charles H. Sternberg and his son
George
George may refer to:
People
* George (given name)
* George (surname)
* George (singer), American-Canadian singer George Nozuka, known by the mononym George
* George Washington, First President of the United States
* George W. Bush, 43rd Presiden ...
. The son collected a unique fossil of the giant bony fish ''Xiphactinus audax'' with the skeleton of another bony fish, ''
Gillicus arcuatus
''Gillicus'' was a relatively small, 2-metre long ichthyodectiform fish that lived in the Western Interior Seaway, in what is now central North America, during the Late Cretaceous.
Description
Like its larger relative, ''Ichthyodectes ctenodon ...
'' inside the larger one. Another excellent skeleton of ''Xiphactinus audax'' was collected by
Edward Drinker Cope
Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontologist, comparative anatomist, herpetologist, and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested ...
during the late nineteenth century heyday of American paleontology and its
Bone Wars
The Bone Wars, also known as the Great Dinosaur Rush, was a period of intense and ruthlessly competitive fossil hunting and discovery during the Gilded Age of American history, marked by a heated rivalry between Edward Drinker Cope (of the Acade ...
.
Viewing and Access
The general type area, the
Smoky Hill River
The Smoky Hill River is a river in the central Great Plains of North America, running through Colorado and Kansas.Smoky Hill River. (2009). In Encyclopædia Britannica. Retrieved July 22, 2009, from Encyclopædia Britannica Online: http://www.br ...
watershed in
Logan
Logan may refer to:
Places
* Mount Logan (disambiguation)
Australia
* Logan (Queensland electoral district), an electoral district in the Queensland Legislative Assembly
* Logan, Victoria, small locality near St. Arnaud
* Logan City, local gover ...
and
Gove Counties, has many
badlands
Badlands are a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded."Badlands" in ''Chambers's Encyclopædia''. London: George Newnes, 1961, Vol. 2, p. 47. They are characterized by steep slopes, m ...
eroded into the Smoky Hill Chalk.
;Some natural monuments of Smoky Hill Chalk in Kansas with public daylight access:
*
Castle Rock
*
Little Jerusalem Badlands State Park
Little Jerusalem Badlands State Park is a state park in Logan County, Kansas, United States. It is owned by The Nature Conservancy and located about south of Oakley and a similar distance north of Scott City.
The park features of Smoky Hill ...
*
Monument Rocks
References
External links
*Everhart, M., nd
Oceans of Kansas Paleontology web page*Everhart, M., nd
*Everhart, M., nd
Geologic formations of the United States
Cretaceous Kansas
Chalk
Lagerstätten
{{Kansas-geologic-formation-stub