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MISSISSIPPIAN SYSTEM
By Edwin D. Goebel
Mississippian rocks are present in the subsurface throughout the State except on the crests of the Central Kansas uplift, the Cambridge arch, the northern and northwestern parts of the Nemaha anticline, and some isolated areas, where they have been removed by early Mississippian, late Mississippian, and early Pennsylvanian erosion (Fig. 6). The only outcropping Mississippian (Keokuk Limestone of Osagian age) is found in a small area in Cherokee County, in the extreme southeastern corner of the State (Fig. 7). Deposits of this age are mostly shallow-water carbonates. The older Mississippian rocks are marine; the younger Mississippian rocks are both marine and nonmarine. The maximum thickness of Mississippian rocks in the Hugoton embayment of southwestern Kansas is more than 1,700 feet.
Figure 6--Late Mississippian and early Pennsylvanian structural provinces and distribution of Mississippian rocks in Kansas (shaded area) (from Goebel, 1966).
Lower Mississippian Series
The Lower Mississippian Series in Kansas consists of beds of shale, limestone, dolomite, and chert. Cherty dolomite predominates.
KINDERHOOKIAN STAGE
An angular unconformity separates rocks of the Kinderhookian Stage from overlying Osagian rocks. The Kinderhookian thickens northward toward a basin in central Iowa, whereas the formations of the Osagian thicken southward (Lee, 1956; Goebel, 1966).
CHOUTEAU LIMESTONE
The Chouteau is the lowermost limestone formation of the Kinderhookian Stage in southeastern Kansas. It resembles the St. Joe Limestone (Osagian), but it is slightly greenish-gray and less granular than the St. Joe. The Chouteau is present only east of the Nemaha anticline. In southeastern Kansas the Chouteau is called the "Compton Limestone." The Chouteau (Compton) ranges in thickness from 0 feet east of the Nemaha anticline and at the Oklahoma border in southeastern Kansas to about 45 feet near Kansas City.
SEDALIA DOLOMITE
The lower Sedalia contains more chert than the upper part. The chert of the lower part is generally ash-gray and characterized by somewhat unique "stippled" markings. The lower part of the Sedalia Dolomite thins southward, and in southeastern Kansas it is equivalent to the Northview Shale.
The upper part of the Sedalia Dolomite consists of noncherty or sparsely cherty buff to gray dolomite, which extends from outcrops in Missouri westward in the Kansas subsurface to the northeastern flank of the Central Kansas uplift. It overlies conformably the lower part of the Sedalia east of the Nemaha anticline, but overlaps upon the Chattanooga Shale to the west. In northwestern Kansas, the upper part of the Sedalia occurs locally below the Gilmore City Limestone (Goebel, 1966). The upper part has a maximum thickness of 30 feet near Kansas City, but it is rarely more than 10 feet thick west of the Nemaha anticline in the Salina basin, where it occurs in local outliers beneath the Gilmore City Limestone or lower Osagian rocks, as in McPherson and adjoining counties.
GILMORE CITY LIMESTONE
Uppermost of the Kinderhookian deposits in Kansas, the Gilmore City Limestone consists of noncherty, soft, chalky limestone enclosing granules of broken calcareous fossils. Some zones are characterized by oolites, including some of irregular shape and black color. In western Kansas, the formation is oolitic limestone and locally contains traces of chert. The Gilmore City Limestone of Kansas occurs northeast and west of the Central Kansas uplift. In northeastern Kansas it lies disconformably upon Sedalia Dolomite. It thickens northwestward from 0 feet in Leavenworth County to 76 feet in Cloud County.
In western Kansas the Gilmore City thickens from 0 feet in dark and Meade counties to more than 150 feet in northwestern Kansas.
OSAGIAN STAGE
Formations in the Osagian Stage consist of dolomite, limestone, chert, and cherty dolomite and limestone beds. The older Osagian formations are restricted to southern Kansas and are overlapped northward by younger formations. Basal Osagian rocks are separated from the underlying Kinderhookian rocks by an angular unconformity.
FERN GLEN LIMESTONE
The Fern Glen Limestone consists of the St. Joe Limestone Member conformably overlain by the Reeds Spring Limestone Member. The Fern Glen is restricted to south-central and southeastern Kansas and lies conformably below the Burlington Limestone in south-central Kansas. The upper member of the formation progressively overlaps northward the lower member as well as older Mississippian rocks. The pattern of distribution of the Fern Glen suggests that the southern part of the Central Kansas uplift and the Nemaha anticline were being gently deformed before or during the deposition of early Osagian rocks (Lee, 1956; Goebel, 1966).
St. Joe Limestone Member
In southeastern Kansas, white, semigranular and coarsely granular noncherty crinoidal limestone is classed as St. Joe Limestone by Lee (1940, 1949, 1953). In the area south of the Central Kansas uplift, the St. Joe is made up of reddish- and greenish-colored calcareous shale and dark-gray argillaceous shale (Goebel, 1966). Erratically distributed reddish-colored crinoidal limestone beds are interspersed in the shale beds. Westward the lower portion of the member contains some lithographic limestone. The St. Joe has a maximum thickness in southeastern Kansas of about 45 feet, farther west it is mostly less than 20 feet, but in Barber County it exceeds 120 feet.
Reeds Spring Limestone Member
Although slightly dolomitic in places, westward from the Kansas-Missouri border the Reeds Spring shows an increase of gray or buff semi-granular and fine-textured limestone. In southeastern Kansas, abundant dark-gray to brown semitranslucent chalcedonic chert and varicolored semiopaque chert occurs. Silica and sponge spicules are common and microscopic crusts of chalcedony are present in insoluble residues. The chert content of the Reeds Spring is high in south-central Kansas, and the chert is pale bluish-gray and semitranslucent to translucent. In areas of Sedgwick, Butler, and Barber counties, the Reeds Spring is noncherty red and grayish-green crinoidal limestone interstratified with cherty limestone. The Reeds Spring has a maximum thickness of 150 feet.
BURLINGTON LIMESTONE AND KEOKUK LIMESTONE, UNDIFFERENTIATED
Although lithologically distinct in some subsurface areas and divided by an important disconformity (Lee, 1956), the Keokuk and Burlington formations are not clearly separable in others. In southeastern Kansas, where the Burlington is absent (Lee, 1940), Keokuk beds are characterized by white tripolitic chert, siliceous limestone, and dolomite. Chert content of the Keokuk throughout Kansas is generally greater than 50 percent by volume and weight (Goebel, 1966). Stratigraphic variations in chert and carbonate content are notable. Toward the north in eastern Kansas, limestone and dolomite beds that probably should be correlated with the Burlington, containing opaque white chert and varying amounts of quartz, underlie the Keokuk (Lee, 1940, 1956). Upper Keokuk rocks closely resemble some Burlington beds, and, where such deposits form a single sequence, they are not readily distinguishable. Near Wichita in Sedgwick County, where the Burlington consists of white semigranular limestone, it is differentiated from underlying limestone beds of early Osagian age only by traces of quartz that is apparent in insoluble residues. The Keokuk rocks are widely distributed in Kansas and formerly covered most, if not all, of the State. The Burlington is not recognized in much of western Kansas (Goebel, 1966). Pre-Pennsylvanian erosion removed Keokuk-Burlington rocks from the Central Kansas uplift, the Cambridge arch, and the northern part of the Nemaha anticline. In southern Kansas, the Burlington seemingly grades downward without a break into Fern Glen deposits, but at the margins of the basins, in western Kansas and especially toward the north in eastern Kansas (Lee, 1956), undifferentiated Burlington-Keokuk beds overlap onto pre-Osagian rocks. The combined thickness of the Keokuk and Burlington ranges from 170 feet or more in southern Kansas to about 100 feet in northern Kansas, and in western Kansas it exceeds 350 feet in thickness.
Upper Mississippian Series
The Upper Mississippian Series in Kansas consists predominantly of beds of limestone and dolomite, with interspersed beds of sandstone and shale, and minor amounts of chert.
MERAMECIAN STAGE
Rocks of the Meramecian Stage lie disconformably on Osagian rocks, but in northeastern and southwestern Kansas the disconformity is obscure. The upper formations consist mostly of granular, sandy, oolitic and fossiliferous limestone, but lower formations contain interbedded dolomite or are mainly dolomite and silty, dolomitic limestone containing variable quantities of chert. Meramecian rocks, except for the Ste. Genevieve Limestone, probably extended originally throughout Kansas but were eroded from much of the State before Pennsylvanian deposits were formed.
"Cowley Facies"—The "Cowley facies" (formerly Cowley Formation) is restricted to an east-west belt 15 to 75 miles wide north of the Oklahoma border in south-central Kansas. Microfossil evidence indicates that the Cowley is a facies of the sequence from the St. Louis Limestone to the Chattanooga Shale (Thompson and Goebel, 1968). The "Cowley facies" is herein adopted for use in Kansas. Silty and siliceous dolomite, limestone, and dolomitic siltstone, and variable amounts of dark, opaque, microfossiliferous chert and chalcedonic chert characterize the "Cowley facies." The beds range locally from gray to black. In southeastern Kansas, grains of glauconite are thinly disseminated throughout and are especially conspicuous in the basal 20 to 30 feet. In southwestern Kansas, chert is less abundant and glauconite is inconspicuous or absent in the basal beds.
WARSAW LIMESTONE
Composed mainly of semigranular limestone interlaminated with saccharoidal dolomite, the Warsaw includes relatively large amounts of distinctive, gray, mottled, opaque, microfossiliferous chert. Glauconite occurs in the lower part. Insoluble residues of some dolomites contain masses of sponge spicules. The Warsaw is unconformable on Keokuk-Burlington beds in central and eastern Kansas (Lee, 1956) and seemingly conformable in western Kansas (Goebel, 1966). It is 30 to 40 feet thick in the Forest City and Salina basins and 250 feet thick in the central part of the Hugoton embayment.
SALEM LIMESTONE
The Salem Limestone conformably overlies the Warsaw Limestone. In northeastern Kansas it consists mainly of noncherty or sparsely cherty saccharoidal to silty dolomite interstratified with noncherty calcarenite, which in some places constitutes the greater part of the formation. The microfossiliferous chert resembles that in the Warsaw. The foraminifer "Endothyra baileyi" commonly is present. In southwestern Kansas, the Salem consists mainly of coarsely crystalline oolitic limestone and saccharoidal dolomite, dolomitic limestone, and chert. Thickness of the Salem is about 50 feet in the deepest part of the Salina basin, where it underlies Pennsylvanian rocks, and in the Forest City basin, where it underlies the St. Louis Limestone. In the Hugoton embayment, it is about 200 feet thick.
ST. LOUIS LIMESTONE
Probably conformable with other Meramecian rocks above and below, the St. Louis contains noncherty lithographic and sublithographic limestone, but also includes remarkably widespread beds of oolitic limestone and calcarenite. Traces of translucent chert contained in semi-granular limestone occur locally. In the deeper part of the Hugoton embayment the St. Louis contains coarsely crystalline fossiliferous limestone and dolomitic limestone. Locally intraformational beds of limestone breccia, chert breccia, and anhydrite are preserved. Although restricted to basin areas, the St. Louis is more widely distributed than the Ste. Genevieve. It is not recognized in the Salina basin. Maximum thickness in the Forest City basin is about 50 feet and in the Hugoton embayment about 200 feet.
STE. GENEVIEVE LIMESTONE
The Ste. Genevieve Limestone, which lies disconformably beneath Chesteran rocks but seemingly conformable on the St. Louis Limestone, occurs in the deeper part of the Forest City basin and is widespread in the Hugoton embayment, but is not recognized in the Salina basin. It consists mainly of silty and sandy white fossiliferous limestone interbedded with fine-textured oolitic limestone and calcarenite. Beds in the Ste. Genevieve cannot be differentiated in areas in which they overlie finely oolitic limestone beds of the St. Louis Limestone. The thickness is about 30 feet in Doniphan and Atchison counties in northeastern Kansas. The thickness is more than 200 feet in the Hugoton embayment, where the formation maintains a constant thickness except where it is beveled by pre-Chesteran or later erosion on the crests and flanks of uplifted areas.
CHESTERAN STAGE
Important unconformities separate the rocks of the Chesteran Stage from Pennsylvanian rocks above and Meramecian beds below. White, semi-granular limestone beds (Batesville) which crop out in northeastern Oklahoma above the Keokuk Limestone may extend into southeastern Kansas (Lee, 1940). Chesteran rocks are unknown in south-central and northern Kansas. In the subsurface of southwestern Kansas, Chesteran rocks are confined to deeper parts of the Hugoton embayment in Morton, Stevens, Seward, Meade, Grant, Haskell, and parts of adjacent counties. They consist of discontinuous beds of sandstone associated with variegated shale beds. Beds of fine-grained sandy limestone and crinoidal limestone are intercalated with pale-green shale. The lower Chesteran rocks locally are silty, grayish-red limestone. Thickness ranges from 0 feet to more than 300 feet near the Oklahoma state line. Locally Chesteran rocks are thin or absent on several structural highs.
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Kansas Geological Survey, Stratigraphic Succession in Kansas
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Web version August 2005. Original publication date Dec. 1968.
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