The Permian rocks of Kingman County are a part of the Leonardian Series and are divided into two groups, the lower of which is the Sumner Group and the upper, the Nippewalla Group (Table 2). The outcropping rocks of the Sumner Group include the Ninnescah Shale, in which the Runnymede Siltstone member forms the upper part, and the Stone Corral Dolomite, which is the top formation of the Sumner Group. The rocks of the Nippewalla Group cropping out in Kingman County include two formations, the Harper Siltstone and the Salt Plain Siltstone. The Harper Siltstone is divided into two members, the Chikaskia Siltstone and the Kingman Siltstone.
The distribution of the Permian rocks is shown on the geologic map (Pl. 1) by the approximate position of the contact of the Sumner and Nippewalla Groups. The general character of the individual formations is apparent in the field, and they are discussed separately in the section that follows. However, the lithology of the rock units is so similar that formation contacts cannot be identified with certainty away from the type areas of the formations.
The Ninnescah Shale, the oldest formation exposed in Kingman County, was named by Norton (1939, p. 1767) from exposures on North and South Forks of Ninnescah River in Reno and Kingman counties. The formation is composed of alternating beds of brownish-red shale, silty shale, and siltstone, and a few thin beds of gray-green silty shale.
The Ninnescah Shale crops out along South and North Forks of Ninnescah River and Chikaskia River and their tributaries in the eastern third of the county and forms a surface of low relief. The formation attains a maximum thickness of about 400 feet along the south edge of the county. The Runnymede Siltstone member, 7 to 8 feet thick, forms the top of the formation. Norton (1939, p. 1767-74) and Swineford (1955) have described the character and thickness of the Ninnescah Shale in detail.
The Ninnescah Shale yields water to many stock and domestic wells in the eastern part of the county where not overlain by younger water-bearing beds. Little is known of the hydrologic properties of the formation, but it is believed to yield water only from the weathered part. The water from the Ninnescah Shale is of good quality in most of its area of outcrop in the county, except in the southeast corner where the water is strongly mineralized.
Stone Corral Dolomite
The Stone Corral Dolomite was named by Norton (1939, p. 1775) from exposures in Rice County. The formation is chiefly anhydrite in the subsurface and is a key marker bed. The Stone Corral Dolomite is exposed along the valley of Smoots Creek in the north-central part of Kingman County, where it is represented by 0.4 foot of dense grayish-buff dolomite. Farther south in the county the Stone Corral is represented by reddish dolomitic silty shale and cannot be distinguished from the shales of the Ninnescah below and the Harper above. The Stone Corral Dolomite yields no water to wells in the county.
The Harper Siltstone was named by Cragin (1896) from exposures in Harper County, Kansas. Norton (1939, p. 1782) removed the Ninnescah Shale and Stone Corral Dolomite from Cragin's Harper Formation and restricted the unit to the beds above the Stone Corral Dolomite and below the Salt Plain Siltstone.
The Harper Siltstone in Kingman County consists of about 210 feet of brownish-red argillaceous siltstone and silty shale and a few beds of silty sandstone. The formation is divided into two members, the Chikaskia Siltstone in the lower part, and the overlying Kingman Siltstone. The formation is well exposed along the valleys of South Fork of Ninnescah River and Chikaskia River in central Kingman County, where the beds form steep valley walls. Swineford (1955, p. 49-57) has described the formation in detail.
The Harper Siltstone yields small supplies of water for stock and domestic use in the central part of Kingman County. The water is believed to occur only in the weathered part of the formation, and the wells commonly fail during drought periods. Younger water-bearing formations overlie the Harper Siltstone in much of the county.
Salt Plain Siltstone
The Salt Plain Siltstone underlies younger water-bearing deposits in much of western Kingman County. The formation crops out in a small area along Chikaskia River north of the town of Zenda. Swineford (1955, p. 57-60) has described the formation in detail. The Salt Plain Siltstone is not known to yield water to wells in Kingman County.
Rocks believed to be equivalent to a part of the Ogallala Formation occur in a small upland area north and east of the city of Kingman. The deposits are lithologically similar to the Delmore Formation described by Williams and Lohman (1949, p. 57-59) in McPherson County and correlated with the Ash Hollow Member of the Ogallala Formation by Frye, Leonard, and Swineford (1956, p. 57). The deposits are composed principally of material derived locally from Cretaceous and Permian rocks. The rocks were probably deposited by a tributary flowing eastward toward a major stream flowing south through a depressional area in McPherson, Harvey, and Sedgwick counties.
Character--The Ogallala(?) Formation is composed of brown to red-brown calcareous silt, fine- to coarse-grained sand, and fine to coarse gravel and cobbles. Locally, the basal gravel and cobbles are cemented with calcium carbonate. Exposures of the formation are poor but are found in road cuts and pit silos in the area.
Coarse, well-rounded pebbles and cobbles of quartz, ironstone, sandstone, weathered granite, and quartzite in part derived from Cretaceous rocks that are no longer present in place in the county, are concentrated locally at the unconformable contact of the Ogallala (?) on older rocks. The sand beds in the formation are composed of fine to coarse grains of iron-stained quartz and some feldspar, mica, and other minerals. The silt is predominantly red brown but in part brown. On the outcrop the formation is characteristically dark reddish brown.
Distribution and thickness--The Ogallala(?) Formation crops out in north-central Kingman County, capping the upland divide between South Fork of Ninnescah River and Smoots Creek. The western boundary of the formation is shown on Plate 1 by a dashed line, as exposures in the area are poor and younger sediments overlie the formation in this area. Test drilling in the area west of the mapped boundary did not reveal sediments typical of the Ogallala(?) Formation, but they are present in adjacent areas of Reno County. The maximum thickness of the formation as determined by test drilling was about 26 feet in test hole 27-6-28ccc.
Age and correlation--The deposits in Kingman County tentatively assigned to the Ogallala(?) Formation are lithologically distinct from the younger Pleistocene deposits in adjacent areas and are in part overlain by the oldest Pleistocene deposits present in the area. The deposits are lithologically similar to middle Pliocene deposits in McPherson County (Delmore Formation), being composed of material derived locally from Cretaceous and Permian rocks but lacking the chert pebbles, derived from Permian limestones to the east, that are common in the McPherson County deposits. Only one fossil is known from the deposits in Kingman County, an upper molar of the Pliocene mastodon Amebelodon (Kansas University Museum of Natural History No. 9967) recovered from a pit silo in the SE sec. 16, T. 27 S., R. 7 W. Although not conclusive, the foregoing evidence points to a Pliocene age for the deposits, and they are tentatively assigned to the Ogallala Formation.
Water supply--The deposits of the Ogallala(?) Formation are relatively thin and of small areal extent and yield small supplies of water for stock and domestic use to only a few wells in the county.
Quaternary System--Pleistocene Series
The Pleistocene Series in Kansas is divided into four main stages related to continental glaciation and three interglacial stages. Events during each of the stages of continental glaciation followed a similar pattern. The cycle in the belt marginal to the glaciated area is characterized by downcutting in stream valleys and some local deposition of sediments during the advance of the glacial ice, then deposition of clastic material, which became progressively finer grained as the glacial front retreated, and finally the development of soil over large areas as surface stability was established.
Although deposits representing all the glacial stages are present in Kingman County and can be recognized in the field and in logs of test holes, some of these units are of such small areal extent or so thin that they are not shown on the geologic map (Pl. 1). Deposits of the Crete(?) Formation (Illinoisan) in isolated areas of the uplands in western Kingman County are mapped with the Grand Island and Sappa Formations, although they are shown separately on the well logs. Deposits believed to be in part equivalent to the Peoria Formation occur locally on most upland divides in the county but are so thin that they are not shown on the geologic map. The terrace deposits representing Wisconsinan deposition and the Recent alluvium, although readily separable in the field, are shown together on the geologic map because of their small areal extent, but they are discussed separately in the section that follows.
Lower Pleistocene Subseries
Holdrege and Fullerton Formations--Nebraskan and Aftonian Stages
Late Nebraskan and Aftonian time in Kingman County is represented by deposits of clay, silt, sand, and gravel of the Holdrege and Fullerton Formations, which unconformably overlie rocks of Permian age. The contact between the Holdrege and Fullerton Formations is not sharp and is arbitrarily placed where the sand and gravel typical of the Holdrege Formation give way to sandy silt. In much of Kingman County where the Holdrege and Fullerton Formations are overlain by younger sediments, the Fullerton Formation contains, in its upper part, a heavy accumulation of caliche and a clay-enriched zone believed to represent remnants of the Afton soil. The Holdrege and Fullerton Formations are shown on the geologic map (Pl. 1) as a single unit, although the Fullerton is absent in part of the area so mapped.
Character--The material composing the Holdrege Formation was deposited by streams that headed in the area west of Kingman County. The material consists of fine to coarse sand and fine to coarse gravel and some sandy silt and clay. The gravel generally is found near the base of the formation and contains pebbles of material derived from Cretaceous rocks, such as ironstone and sandstone. The sand and gravel consists predominantly of quartz grains but contains much feldspar, some mica, and a few dark minerals. The silt beds in the Holdrege Formation are generally thin, are very sandy, and in many places contain a small amount of clay. The silt is generally pinkish tan but some tan and gray silt is present. Thin zones of lime-cemented sand are found locally in the upper part of the formation.
The Fullerton Formation consists predominantly of tan to gray sandy silt and locally contains thin zones of silty sand. In much of central and western Kingman County where the Fullerton Formation is overlain by younger sediments and thus protected from erosion the upper part of the formation contains much clay and a zone of heavy caliche accumulation believed to be a remnant of a well-developed Afton soil.
Distribution and thickness--The Holdrege and Fullerton Formations are present over most of Kingman County except where removed by erosion in the valleys of Chikaskia and Ninnescah Rivers in the central and eastern parts of the county. These formations probably formed a coalescent sheet over the county during Aftonian time except in an area of high bedrock in the southwestern part of the county (Section A-A', Pl. 2). Younger sediments later buried the Nebraskan sediments. Erosion by streams of steeper gradient during late Pleistocene time cut deeply into the Nebraskan and younger sediments and the underlying Permian bedrock, exposing these formations along present valleys in the county. Overlying younger sediments and the Fullerton Formation and part of the Holdrege Formation were removed in eastern Kingman County, and the relative topographic position of the Nebraskan sediments was changed. In western and central Kingman County the Nebraskan sediments fill buried valleys of low gradient, top low divides in the Permian bedrock, and remain buried by younger sediments in much of the area. In the eastern part of the county, present streams have cut below the level of the Nebraskan valleys, and remnants of the Nebraskan valley fills form the highest topographic elements in the area. The combined thickness of the Holdrege and Fullerton Formations ranges from 0 in parts of Kingman County to a maximum of about 162 feet in test hole 27-9-6bbb.
Age and correlation--A late Nebraskan and early Aftonian age for the Holdrege and Fullerton Formations in Kingman County is indicated by vertebrate and invertebrate fossils collected at three localities in the county and by their stratigraphic position, which places them as the oldest Pleistocene rocks in the county.
The fossils collected in Kingman County were taken from sediments of the Fullerton Formation and were associated with or were below the zone of caliche accumulation believed to be a part of the Afton soil profile. The sites of the fossil collections are in the NW SW sec. 23, T. 30 S., R. 9 W., known as the Swingle locality; in the SW sec. 12, T. 29 S., R. 8 W., known as the Dixon locality; and in the SE NE sec. 23, T. 30 S., R. 5 W., known as Dixon locality 2.
The vertebrate fossils from the Dixon locality were identified and described by Hibbard (1956) and Tihen (1955) and the invertebrates by Frye and Leonard (1952). The vertebrates from Dixon locality 2 were identified by Hibbard (1957). No vertebrates were recovered at the Swingle locality. The invertebrates recovered at Dixon locality 2 and the Swingle locality were identified by Dr. Dwight W. Taylor and are listed below. The species name is followed by the University of Michigan Museum of Zoology catalog number, and the number of specimens in parentheses.
|Fossil mollusks from Swingle locality,
SW SW sec. 23, T. 30 S., R. 9 W.
|Pisidium compressum Prime||191478(24)|
|Lymnaea caperata Say||191480(33)|
|Gyraulus parvus (Say)||191481(11)|
|G. circumstriatus (Tryon)||191482(2)|
|Helisoma trivolvis (Say)||191483(1)|
|Promenetus umbilicatellus (Cockerell)||191484(3)|
|Gastrocopta armifera (Say)||191486(4)|
|G. cristata (Pilsbry and Vanatta)||191487(8)|
|G. pellucida hardeacella (Pilsbry)||191488(42)|
|G. tappaniana (Adams)||191489(5)|
|Pupoides albilabris (Adams)||191490(4)|
|Vertigo milium (Gould)||191491(5)|
|V. ovata Say||191492(6)|
|Vallonia gracilicosta Reinhardt||191493(5)|
|V. parvula Sterki||191494(3)|
|V. sp. (young of one or both of the above two species)||191495(6)|
|Helicodiscus parallelus (Say)||191497(6)|
|H. singleyanus (Pilsbry)||191498(2)|
|Deroceras aenigma Leonard||191499(1)|
|Hawaiia minuscula (Binney)||191500(55)|
|Fossil mollusks from Dixon locality 2,
SE NE sec. 23, T. 30 S., R. 5 W.
|Sphaerium partumeium (Say)||191501(109),
|Valvata tilcarinata (Say) form perconfusa Walker||191503(33)|
|Lymnaea palustris (Müller)||191505(250)|
|L. caperata Say||191506(41)|
|L. dalli Baker||191507(2)|
|L. megasoma Say||191508(15)|
|Gyraulus parvus (Say)||191509(300)|
|Helisoma anceps (Menke)||191510(1)|
|H. trivolvis (Say)||191511(72)|
|Planorbula armigera (Say)||191512(200)|
|Promnetus kansasensis (Baker)||191513(150)|
|P. umbilicatellus (Cockerell)||191514(6)|
|Ancylus coloradenis Henderson||191515(1)|
|Ferrissia pumila Sterki||191516(43)|
|Physa elliptica Lea||191517(65)|
|P. skinneri Taylor||191518(22)|
|Gastrocopta cristata (Pilsbry and Vanatta)||191519(2)|
|G. procera (Gould)||191520(11)|
|G. pellucida hardeacella (Pilsbry)||191521(3)|
|G. n. sp.||191522(6)|
|G. tappaniana (Adams)||191523(32)|
|Pupoides albilabris (Adams)||191524(16)|
|Vertigo milium (Gould)||191525(25)|
|V. oviata Say||191526(4)|
|Oxyloma ref. O. haydeni (Binney)||191528(27)|
|Helicodiscus parallelus (Say)||191529(18)|
|H. singleyanus (Pilsbry)||191530(400)|
|Deroceras aenigma Leonard||191531(6)|
|Hawaiia minuscula (Binney)||191532(150)|
According to Dr. Taylor (written communication),
"the collection from SE1/4 NE1/4 sec. 23, T. 30 S., R. 5 W., is so similar to the already known Dixon local fauna that I am including it in that assemblage as Dixon locality 2. . . . The climate when the Dixon local fauna was living was certainly different from that of Kingman County today. Apparently the summers were not much different, but winter precipitation was probably much greater. Such conditions could result in much more surface water than now persists through the summer, but in a climate with summers like those of today. This climate is believed to be very late glacial rather than interglacial, and the Dixon local fauna very late Nebraskan. The collection from NW1/4 SW1/4 sec. 23, T. 30 S., R. 9 W. (Swingle site), is probably interglacial rather than glacial. There are not many species and I can't be too sure of correlation. The fauna shows that summers were not quite as hot and dry as they are in southern Kansas today, but winters were no colder. It is possible that this assemblage is of the same age as the Dixon local fauna, and differs only because of local habitat. I believe, however, that it is more probably Aftonian than even very late Nebraskan. The fauna may be correlative with the Aftonian Sanders local fauna [Hibbard, 1956] of Meade County, but the mollusks can't prove this. I can ascribe it only to some unknown part of the varied Aftonian interglacial."
Water supply--The Holdrege Formation is the principal source of ground water in Kingman County. The quantity of water that may be obtained from the Holdrege Formation is different from place to place, owing to differences in the thickness and physical character of the sand and gravel in the formation. Supplies of water adequate for domestic and stock use are available in most of the area underlain by the formation. In parts of Kingman County the saturated thickness of the formation is adequate for large water supplies for municipal, irrigation, and industrial use. The water from the Holdrege Formation is moderately hard but is satisfactory for most uses.
The Fullerton Formation is composed principally of sandy silt and clay and does not readily yield water to wells. In parts of Kingman County the Fullerton Formation lies below the water table, and wells penetrating sandy zones in the formation might yield small water supplies adequate for stock and domestic use.
Grand Island and Sappa Formations--Kansan and Yarmouthian Stages
Kansan and Yarmouthian time in Kingman County is represented by stream-deposited clay, silt, sand, and gravel of the Grand Island and Sappa Formations. The Grand Island Formation rests unconformably on the Fullerton Formation and locally on Permian rocks, and grades upward into sandy silt and clay of the Sappa Formation. The contact between the Grand Island and Sappa Formations is not sharp and is arbitrarily placed where the rock changes from sandy to predominantly silty. A heavy accumulation of caliche and a clay-enriched zone in the upper part of the Sappa Formation in parts of western Kingman County are believed to represent remnants of the Yarmouth soil. The Grand Island and Sappa Formations are shown on the geologic map (Pl. 1) as a single unit, although the Sappa is absent in part of the area so mapped.
Character--The Grand Island Formation consists of fine to coarse sand and fine to coarse gravel and minor amounts of silt. The sand of the Grand Island Formation is mostly quartz but contains much feldspar and other minerals typical of igneous rocks. Gravel is found throughout the formation but is most common near the base. The gravel is coarser than that in the Holdrege Formation and contains rock types common to the Rocky Mountain area; locally derived gravel of the kind common in the Holdrege Formation is not found in the Grand Island Formation. These facts may indicate that through drainage from the Rocky Mountains first reached central Kansas in late Kansan time. Silt beds in the Grand Island Formation are thin, contain much sand, and are tan.
The Sappa Formation consists of gray to tan sandy silt, which becomes clayey in the upper part of the formation. In extreme western Kingman County the Sappa Formation contains a heavy zone of caliche in the clay-enriched zone, which is believed to represent a remnant of the Yarmouth soil. A lenticular bed of volcanic ash, the Pearlette Ash bed (Carey and others, 1952), is found in the stratigraphic position of the Sappa Formation at widely distributed locations throughout the midcontinent region from Texas to South Dakota and from Colorado to Iowa and is an important stratigraphic marker in the Pleistocene of the region (Frye and Leonard, 1952). Two deposits of the Pearlette Ash bed are known in Kingman County. A small deposit about 2 feet thick crops out in the NW NE sec. 16, T. 29 S., R. 10 W., and a deposit of unknown extent, buried under Recent slope deposits, is present in the NW sec. 30, T. 28 S., R. 7 W.
Distribution and thickness--Valley cutting, which was common in Nebraskan time, does not seem to have been extensive in Kingman County during Kansan time. The Grand Island and Sappa Formations seem to have been deposited by streams that shifted laterally over a relatively flat eastward-sloping surface. The formations may have formed a coalescent sheet over the entire area of Kingman County during Yarmouthian time. Erosion during late Pleistocene time removed the formations from most of eastern Kingman County (Pl. 1), and the deposits now are found only on the upland divides in the central and western parts of the county. The Sappa Formation has been removed in the central part of the county except in isolated areas on the crests of divides. In extreme western Kingman County all but the upper part of the Sappa Formation remains intact and underlies the surface in that area. The Grand Island and Sappa Formations are thickest along the western border of the county. Although the thickness is not definitely known, it is estimated to be as much as 150 feet. Eastward, the formations have been thinned by erosion to a featheredge in the central part of the county.
Age and correlation--A late Kansan to early Yarmouthian age for the Grand Island and Sappa Formations is indicated by the stratigraphic position of the Grand Island, which unconformably overlies deposits of late Nebraskan to Aftonian age, and by the occurrence of the late Kansan Pearlette Ash bed in the Sappa silts overlying the Grand Island Formation. No fossils were found in the Grand Island and Sappa Formations in Kingman County.
Water supply--The Grand Island lies above the water table in most of its area of occurrence in Kingman County, and where it does it yields no water to wells. In the extreme western part of the county, where the formation is thickest it is the principal aquifer supplying water to domestic and stock wells. The formation in that area is capable of yielding large water supplies adequate for municipal, irrigation, and industrial use. The city of Cunningham is supplied from two wells finished in the Grand Island Formation; and irrigation well 28-10-5dbb, which also is in the Grand Island Formation, is reported to have yielded 1,000 gpm during a pumping test. The water from the Grand Island Formation is moderately hard but suitable for most uses. The Sappa Formation lies above the water table and does not yield water to wells in Kingman County.
Upper Pleistocene Subseries
Crete(?) Formation--Illinoisan Stage
Deposits of silt, sand, and gravel believed to be the Crete Formation of late Illinoisan age are present at scattered localities in western Kingman County, form terraces adjacent to Smoots Creek in the northeastern part of the county, and fill a buried valley in the east-central part of the county. The anomalous distribution of the Crete(?) Formation suggests the occurrence of a major change in the master stream of the area, and resulting adjustments in its tributaries, in late Illinoisan time.
In western Kingman County isolated deposits of the Crete(?) Formation consisting of arkosic sand and gravel lie unconformably on the Sappa Formation and locally fill small channels cut into that formation. In other parts of western Kingman County the Crete(?) Formation forms a thin veneer of coarse gravel resting on the Sappa Formation. The maximum thickness of the Crete(?) Formation in the western part of the county is not known, but 12 feet of sand and gravel overlying the Sappa Formation was penetrated by test hole 29-9-6bbb. Deposits of the Crete(?) Formation in the western part of the county are so small and scattered that they are not shown on the geologic map (Pl. 1).
Deposits of silt, sand, and gravel believed to be the Crete(?) Formation form a terrace on the northeast side of Smoots Creek in northeastern Kingman County. These deposits occupy a broad channel cut into the Permian bedrock, but its floor is at a higher altitude than bedrock under the present Smoots Creek (Section E-E', Pl. 2). Erosion has removed the Crete(?) Formation near South Fork of Ninnescah River. Southeast from the northward bend in T. 29 S., R. 5 W., a buried valley, which has been traced by test drilling, leaves Kingman County, crosses the comer of Sedgwick County, and joins the Slate Creek valley in Sumner County. The silt, sand, and gravel filling this buried valley are believed to be the Crete Formation, and the valley may be a continuation of the late Illinoisan(?) valley adjacent to Smoots Creek. The maximum thickness of the Crete(?) Formation in eastern Kingman County as determined by test drilling was 50 feet in test hole 27-5-29ccc.
Water Supply--In western Kingman County the Crete(?) Formation lies above the water table and thus does not yield water to wells. Permeable sand and gravel of the Crete(?) Formation adjacent to Smoots Creek are capable of yielding moderately large water supplies adequate for small-scale irrigation and industrial use. Industrial well 27-5-33abb is reported to yield 350 gpm continuously; and irrigation well 27-6-6ccd, a battery of eight closely spaced small-diameter wells, is reported to yield 260 gpm. The Crete(?) Formation in the buried channel in T. 29 S., R. 5 W., supplies water for domestic and stock use. The water from the Crete(?) Formation is moderately hard but is satisfactory for most uses.
Terrace Deposits--Wisconsinan Stage
There are low terraces at two distinct levels in the valleys of South Fork of Ninnescah River, Chikaskia River, and their principle tributaries in Kingman County. The deposits underlying the upper terrace, which are not continuous, contain fossil mollusks that have been dated as early Wisconsinan (Frye and Leonard, 1952). A late Wisconsinan age is assumed for the more widespread lower terrace because of local traces of abandoned meanders on its surface and because of its position above the Recent alluvium of the streams and below the early Wisconsinan terrace surface. The materials underlying the terraces consist principally of silt, sand, and gravel derived from older Pleistocene deposits. Where the deposits are entrenched in Permian rocks, they contain abundant pebbles of Permian shale. The deposits are limited to the floors of the major valleys and average about 0.75 mile in width. The maximum thickness of the terrace deposits penetrated by test drilling was 49 feet in test hole 30-8-6bcb, but the average is about 40 feet. The Wisconsinan terrace deposits and the Recent alluvium are shown as a single unit on the geologic map (Pl. 1).
Water supply--The sand and gravel of the Wisconsinan terrace deposits is capable of yielding moderately large water supplies, particularly adjacent to the rivers where induced filtration of river water by pumping will readily recharge the aquifer. The city of Kingman supplements its municipal water supply with five wells in terrace deposits of South Fork of Ninnescah River. Of these, three are capable of producing 250 to 300 gpm each, and two small-diameter wells are capable of producing about 90 gpm each. Irrigation well 30-6-9dac in terrace deposits along Chikaskia River is reported to yield about 300 gpm. The water in the terrace deposits adjacent to South Fork of Ninnescah River is of poor quality, containing an excessive amount of chloride derived from the river water. In the terrace deposits away from the river the water is moderately hard but is low in chloride and is satisfactory for most uses. The water in the terrace deposits along Chikaskia River is moderately hard.
Deposits of silt, containing some sand and gravel, overlie Permian rocks in large areas of central and eastern Kingman County. The deposits are on gentle slopes adjacent to major streams and are the result of mass movement of debris from the bordering uplands toward the major drainages by sheet wash and soil creep. The colluvial deposits in Kingman County are particularly well developed on the Ninnescah Shale, which is easily eroded and forms gentle slopes. Where widespread, the deposits have the general appearance of a broad alluvial terrace and in many places blend imperceptibly with the terrace deposits bordering the streams. The age of the colluvial deposits is uncertain but some may in part be as old as late Illinoisan and some are still being deposited at the present time. The maximum thickness of colluvium penetrated by test drilling was 23 feet in test hole 30-5-29ddd. The deposits lie above the water table generally but where below the water table and where sufficiently thick and permeable are capable of yielding small supplies of water.
Several areas in Kingman County are underlain by deposits of fine to medium sand containing some silt and displaying a typical dune topography. The largest area of sand dunes in the county is in the southwest corner, in T. 30 S., R. 10 W., and is an extension of a larger tract of dunes in Pratt County to the west. The dunes in this area generally are stabilized by vegetation, but blowouts are common when the vegetative cover is removed. There is another large tract of dunes along the north side of Chikaskia River in T. 30 S., R. 6 W. Some dunes adjacent to the river are active, but those away from the river generally are subdued and have a cover of vegetation. Other isolated areas in eastern Kingman County are underlain by gently rolling sand dunes (Pl. 1) and are successfully cultivated in years of normal rainfall. The maximum thickness of the dune sand probably does not exceed 30 feet, and in the areas of gently rolling subdued dunes the thickness does not exceed 6 feet. The age of the dune sand is uncertain, but the sand movement may have begun as early as late Wisconsinan time and in isolated areas bordering the major streams is still going on. The dune sand lies above the water table and thus does not supply water to wells in the county.
Deposits of Recent alluvium are present in and adjacent to the channels of South and North Forks of Ninnescah River, Chikaskia River, and their major tributaries in Kingman County. The alluvium is confined to a narrow belt adjacent to the present stream channels and is not more than 200 feet wide, except in a few places. The surface of the Recent alluvium generally lies 2 to 4 feet below the late Wisconsinan terrace, and the stream channels, commonly box shaped, are incised 2 to 6 feet in the alluvial fill. The alluvium is composed of silt, sand, and fine gravel derived from older Pleistocene deposits and, where adjacent to Permian bedrock, contains abundant fragments of these rocks. The thickness of the alluvium is not definitely known, but the 30 feet of alluvium penetrated in test hole 28-5-35ada is believed to be about average. So far as is known no wells in Kingman County penetrate alluvium of the major streams, as the flood plain it forms is periodically flooded. However, wells could be located on the flood plain if they were constructed so as to prevent flood damage, and they should yield large quantities of water by induced infiltration of river water. Wells on the adjacent terrace should have similar yields.
Kansas Geological Survey, Geology
Placed on web Sept. 8, 2008; originally published March 1960.
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