- Clements Stone Arch Bridge [15] over the Cottonwood River
Cottonwood Limestone | |
---|---|
Stratigraphic range: Early Permian | |
Type | Formation Member |
Unit of | Beattie Limestone |
Sub-units | Top Ledge, Bottom Ledge |
Underlies | Florena Shale member of the Beattie Limestone formation |
Overlies | Eskridge Shale |
Thickness | 3–7 ft (0.91–2.13 m) often ~6 ft (1.8 m) |
Lithology | |
Primary | Limestone |
Other | Calcareous shale and siliceous to quartz[ clarification needed ] nodules or infills of burrows |
Location | |
Region | Mid-continental |
Country | United States |
Extent | Outcrops from southeast Nebraska to northeast-central Oklahoma [1] |
Type section | |
Named for | Cottonwood Falls, Kansas |
Named by | Prosser, C. S. |
Year defined | 1895 [2] |
Cottonwood Limestone, or simply the Cottonwood, [3] is a stratigraphic unit and a historic stone resource in east-central Kansas, northeast-central Oklahoma, and southeastern Nebraska in the Midwestern United States. [1] 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.
This important building stone, quarried in the Cottonwood River valley, had been used under the names "Cottonwood stone" or "Cottonwood Falls limestone" many years before the name Cottonwood Limestone appeared in scientific publications late in the 19th century. Similarly, "Manhattan stone" was the commercial name used for the same limestone when quarried in the vicinity of Manhattan, Kansas. [2] It was also called "Alma Limestone" when first quarried at Alma, Kansas. [4] [5]
The Cottonwood Limestone is one of the most persistent and easily recognizable horizons in Kansas. [4] [6] This limestone is usually light gray or buff in color, massively bedded, and has an average thickness of about six feet. The upper part of the member in particular is recognizable for being almost entirely made up of the small wheat-grain shaped foraminifera Fusulinida, with few other animal remains. The line of outcrop of the Cottonwood is generally marked by a line of massive rectangular blocks of light gray or bleached, bone-colored limestone, often supporting a line of shrubs. Because of its resistance to weathering, it often forms a prominent escarpment. The Cottonwood Limestone is noteworthy for the persistence of this lithologic character across its range.
Aside from shaping the landscapes of the communities within the Flint Hills, this limestone is most notable for its influence on the building architectures of the communities in its region. Near the surface, Cottonwood Limestone is a useful aquifer, while deeper subsurface Cottonwood Limestone is associated with oil and gas producing formations.
A regionally famous construction material, Cottonwood Limestone is yellowish, buff, to nearly white in color, even-textured, durable, and very suitable for cutting into dimensional stone for masonry. Moreover, its beds of usable stone are particularly massive for the region; blocks of stone three or more feet thick and several feet in length and width can be taken from a ledge. [7] While many other limestone formations are found in the region and have been widely used in local construction, most (excepting most notably the Fort Riley Limestone [8] ) weather poorly, lie with much thinner parting beds, or are generally much higher in the typical Permian silica or flint content and so are much more difficult to cut or sculpt. [3] As such, the lithologic characteristics of Cottonwood Limestone has made it one of the best building stones in the state and many past quarries, large and small, may be found on nearly every hill capped by this resource. [2]
Large, cut blocks of Cottonwood Limestone were famously used in historic, monumental buildings in the region, including churches, courthouses, and educational buildings; while rough stones of other limestones are more common in older, smaller homes and buildings. Its use in a building within its region can often be recognized by the use of large cut blocks, near-white or buff color, and showing abundant fossils or molds of “wheat-grain” shaped fusulinids coupled with general absence of spalling, splotchy black coloring from mold that find portions of the stone particularly favorable, and sculptured or protruding rough faces. Especially in older buildings close to a source, Cottonwood Limestone is sometimes paired with the Neva Limestone that is commonly exposed only 35 feet lower in the hills. In this combination, the softer, massive Cottonwood is used for carved trim while the Neva is used, cut or rough, for the general fill and facing, [9] the latter showing a whiter face with smoother glass-like fracture in contrast to the more buff-colored Cottonwood Limestone showing a rougher earthy fracture.
The Cottonwood is the main facing material for the campus buildings of Kansas State University. [2] The Topeka Performing Arts Center [10] as well as much of the Kansas State Capitol [7] and the Great Overland Station [11] in Topeka, Kansas are constructed with Cottonwood Limestone. The iconic Campanile in Lawrence, Kansas, is also built from the once-named “Manhattan stone”. [12] Cottonwood Limestone continues to be popular in constructions, [13] and was recently (2014) used to construct the West Side Stadium Center of the Bill Snyder Family Football Stadium. [14]
The massive, fine-grained, bright-white character of this limestone makes it a practical stone for large sculptures:
The Cottonwood is a reliable surface limestone aquifer in the region. The brush line seen on many hillsides at the base of this member indicates the moisture it provides. Many springs issue from beneath the massive ledge, especially the west-facing exposures—many of which serve as a source of water for livestock. [9] [19] In many places, springs or shallow wells from the Cottonwood provide large supplies of water for domestic home and farm use. This is especially true along westward-facing hillsides, as strata generally dip to the northwest. [2]
Natural gas has been produced in the Cottonwood Limestone in southwestern Kansas and northwestern Oklahoma. The member made an impact on gas production in the region in the 1960s and 1970s, particularly in the discovery of additional reserves in previously established and even abandoned fields. [20] [21] [22]
As the prominent member of the Beattie Limestone formation, Cottonwood Limestone can be traced on the outcrop from Nemaha County, Nebraska, southward to Osage County, Oklahoma, and followed in the subsurface westward to the vicinity of the Colorado-Kansas line as well as into northwestern Oklahoma. [1] [23]
The surface outcropping of the Cottonwood Limestone is easily traced in the Flint Hills south of the Kansas River and east of Manhattan, Kansas. In Manhattan, it forms the scenic ridges surrounding the old downtown in the southeast of the city. From there, the line of outcrop is a tortuous one extending several miles north and west along the Kansas and Big Blue rivers and their tributaries. [2]
This limestone forms extensive outcrops in the Cottonwood River valley that shares its name; outcrops can be followed several miles up every tributary valley around Cottonwood Falls. [4]
The Cottonwood Limestone is a marine limestone and calcareous shale, laterally persistent, bench-forming, and notably and consistently showing abundant fossils. An outstanding example of uniformity of thickness over considerable areas, the outcrop of the Cottonwood Limestone over a distance of 150 miles from Nebraska to central Kansas is nowhere less than 5.5 nor more than 6.5 feet. [1] The notable consistency of these characteristics within its range serves to make it a distinctive marker bed. Even so, there are some changes in lithologic character that can be seen from north to south.
In the central and north range, the limestone is recognized to have distinct the upper and lower beds, long known as Top Ledge and Bottom Ledge, [24] which commonly part when weathered. This boundary between the upper and lower Cottonwood is evidenced by a sharp textural contrast, porosity difference, and changes in the opaque mineral content. [3] In this range, the whole member is fine-grained limestone, [25] but the Top Ledge has a yellower tint or a creamy gray with open grain while the Bottom Ledge is whiter with tight grain. [26] [27] With respect to fossil content, the upper weathering bed is characterized by the abundant Fusulinid assemblage, while the lower bed is composed of minute particles of various fragmented fossils, especially Osagia, echinoderms, and bryozoans. [25]
In northern east-central Kansas, Cottonwood Limestone forms particularly prominent outcroppings in the Flint Hills, especially in the Cottonwood River valley in Chase County, Neosho River valley in Morris County, and the Kansas River and Big Blue River valleys of Riley County. There, it often forms a very conspicuous hillside bench characterized by massive light-gray rounded limestone blocks. The presence of the Cottonwood Limestone in a hillside here is often marked by a persistent line of shrubs that can be seen for many miles. Wherever seen in these and nearby valleys, the Cottonwood Limestone member is almost uniformly six feet thick. It is everywhere massive and commonly seems to consist of only one or two beds. The limestone on a fresh fracture is yellowish gray to buff in color, weathering to light gray. [4] Fusulinids are common, especially in the upper part, and siliceous nodules project from weathered surfaces. Close observation removes any likelihood of confusing the Cottonwood Limestone with any other layer in this part of Kansas; its distinguishing characters are the massive ledge of uniform thickness, the silicified nodules, and the abundance of fusulinids, chiefly in the resistant upper part. The Cottonwood is not a flinty limestone such as those seen higher on the surrounding hilltops; however, nodules, concretions, and trace fossils (filled-in burrows) of partly silicified material that weather more slowly than the rest of the member can give the limestone an appearance of containing flint. [2]
While the abundance of fusulinids remains a characteristic of the top of the Cottonwood through to Osage County, Oklahoma, [28] south of Chase County, Kansas the member has lost its massive limestone characteristic and does not form the conspicuous outcrops seen farther north. [29] In Greenwood County, Kansas, the unit appears as light-gray limestone crowded with horizontal thin leaves of platy algae, attaining a maximum observed thickness of 8 feet. [28] The Cottonwood in southern Kansas and northern Oklahoma is an interbedded limestone and calcareous shale with a very diverse, abundant, and well-preserved fossil fauna, especially brachiopods, mollusks, and ammodiscid foraminifera (shelly facies). At the southern limit of its outcrop the Cottonwood Limestone is a medium crystalline limestone with thin, shelly layers. Mollusks, Osagia, and quartz silt are common (silty Osagia facies). [25]
Variations in the characteristic content and texture (facies) of the limestone reflect lateral changes in the environment from north to south. [3] [25]
The Cottonwood Limestone is easily accessed or viewed in several locations:
Strong City is a city in Chase County, Kansas, United States. Originally known as Cottonwood Station, in 1881 it was renamed Strong City after William Barstow Strong, then vice-president and general manager, and later president of the Atchison, Topeka and Santa Fe Railway. As of the 2020 census, the population of the city was 386. It is located along U.S. Route 50 highway.
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 chemical precipitate or a diagenetic replacement, as in petrified wood.
The Onondaga Limestone is a group of hard limestones and dolomites of Devonian age that forms geographic features in some areas in which it outcrops; in others, especially its Southern Ontario portion, the formation can be less prominent as a local surface feature.
The Flint Hills, historically known as Bluestem Pastures or Blue Stem Hills, are a region of hills and prairies that lie mostly in eastern Kansas. It is named for the abundant residual flint eroded from the bedrock that lies near or at the surface. It consists of a band of hills extending from Marshall and Washington Counties in the north to Cowley County, Kansas and Kay and Osage Counties in Oklahoma in the south, to Geary and Shawnee Counties west to east. Oklahomans generally refer to the same geologic formation as the Osage Hills or "the Osage."
The Smoky Hills are an upland region of hills in the central Great Plains of North America. They are located in the Midwestern United States, encompassing north-central Kansas and a small portion of south-central Nebraska.
Tuttle Creek Lake is a reservoir on the Big Blue River 5 miles (8 km) north of Manhattan, in the Flint Hills region of northeast Kansas. It was built and is operated by the Army Corps of Engineers for the primary purpose of flood control. Secondary functions of the project include release of water stores to maintain barge traffic on the Mississippi River during seasons of drought, maintenance of a multi-use conservation pool for fish and wildlife enhancement and recreation, and release of sufficient water in droughts to maintain water quality for downstream communities.
The geology of Kansas encompasses the geologic history and the presently exposed rock and soil. Rock that crops out in the US state of Kansas was formed during the Phanerozoic eon, which consists of three geologic eras: the Paleozoic, Mesozoic and Cenozoic. Paleozoic rocks at the surface in Kansas are primarily from the Mississippian, Pennsylvanian, and Permian periods.
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 composed of two structural units, the Smoky Hill Chalk Member overlying the Fort Hays Limestone Member. The chalk formed from the accumulation of coccoliths from microorganisms living in what was once the Western Interior Seaway, an inland sea that divided the continent of North America during much of the Cretaceous. It underlies much of the Great Plains of the US and Canada. Evidence of vertebrate life is common throughout the formation and includes specimens of plesiosaurs, mosasaurs, pterosaurs, and several primitive aquatic birds. The type locality for the Niobrara Chalk is the Niobrara River in Knox County in northeastern Nebraska. The formation gives its name to the Niobrara cycle of the Western Interior Seaway.
The geology of East Sussex is defined by the Weald–Artois anticline, a 60 kilometres (37 mi) wide and 100 kilometres (62 mi) long fold within which caused the arching up of the chalk into a broad dome within the middle Miocene, which has subsequently been eroded to reveal a lower Cretaceous to Upper Jurassic stratigraphy. East Sussex is best known geologically for the identification of the first dinosaur by Gideon Mantell, near Cuckfield, to the famous hoax of the Piltdown man near Uckfield.
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 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 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 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 Fort Riley Limestone is a Permian stratigraphic unit and historic building stone, sold commercially as fine-grained Silverdale, at one time being quarried at Silverdale, Kansas. The limestone outcrops in east-central Kansas, northeast-central Oklahoma, and southeastern Nebraska in the Midwestern United States. Its outcrop caps the bluffs overlooking the original buildings of Fort Riley.
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 Kananaskis Formation is a geologic formation that is present on the western edge of the Western Canada Sedimentary Basin in the southern Canadian Rockies of western Alberta. Named after the Kananaskis Range near Banff, it was deposited during the Late Pennsylvanian sub-period of the Carboniferous period. Some of its strata host fossils of marine invertebrates.
Fencepost limestone, Post Rock limestone, or Stone Post is a stone bed in the Great Plains notable for its historic use as fencing and construction material in north-central Kansas resulting in unique cultural expression. The source of this stone is the topmost layer of the Greenhorn Limestone formation. It is a regional marker bed as well as a valued construction material of the late 19th and early 20th centuries in Kansas. This stone was very suitable for early construction in treeless settlements and it adds a notable rust orange tint to the region's many historic stone buildings. But the most famous use is seen in the countless miles of stone posts lining country roads and highways. This status gives rise to such regional appellations as Stone Post Country, Post Rock Scenic Byway, and The Post Rock Capital of Kansas. This rustic quality finds Fencepost limestone still used in Kansas landscaping today.
The Goat Seep Formation is a geologic formation found in western Texas and southeastern New Mexico. It is a fossilized reef dating to the Guadalupian Age of the Permian period.
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.