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Eastern Shawnee County

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Stratigraphy, continued

Pennsylvanian System

Des Moines Series

The Pennsylvanian rocks of the Des Moines Series in the report area are divided into the Cherokee and Marmaton Groups.

Cherokee Group

Rocks of the Cherokee Group, about 530-600 feet thick, consist primarily of medium-gray shale and siltstone but include olive- to greenish-gray shale and some dark-gray and black shale associated with many thin coal beds. Some thin beds of medium dark-gray argillaceous limestone and dolomite are also present, particularly in the upper half of the group. White to light-gray very fine grained to medium-grained, partly limy or dolomitic sandstone is common in the lower half of the Cherokee, and beds as much as 30 feet thick occur in places. In the Murchison Federal Land Bank 1 well, a very light gray to very pale orange chert conglomerate 5 feet thick occurs at the base of the Cherokee. The chert is dense, quartzose, tripolitic, or spicular, and is imbedded in a siltstone matrix containing reddish-brown ironstone fragments, medium to very coarse quartz grains, glauconite, and pyrite.

Marmaton Group

The Marmaton Group is about 120-140 feet thick and consists mainly of medium-gray, greenish-gray, and some dark-gray and black limy shale and siltstone and light-gray, very pale orange, and pale-yellowish-brown argillaceous partly dolomitic and generally fossiliferous limestone. Some light-gray to pale-yellowish brown very fine grained sandstone and coal are also present. The limestone and greenish-gray shale are most abundant in the upper part of the Marmaton.

Missouri Series

The Missouri Series in the report area comprises the Pleasanton, Kansas City, and Lansing Groups. Both the Kansas City and Lansing Groups are divided into separate formations.

Pleasanton Group

In the mapped area, rocks of the Pleasanton Group range in thickness from 85 to 140 feet. They consist predominantly of medium gray to medium-dark-gray silty shale and siltstone but include some light-gray to medium-light-gray very fine grained silty, limy micaceous sandstone. The shale and siltstone are in part limy and slightly micaceous.

Kansas City Group

Rocks of the Kansas City Group are about 230-280 feet thick and are principally limestone but include a thick shale at the top. In the Murchison Federal Land Bank 1 well and in the J. J. Lynn Warner 1 well (pl. 2), the upper part of the Kansas City is divided, in ascending order, into the Iola Limestone, Lane Shale, Wyandotte Limestone, and Bonner Springs Shale. The part of the Kansas City below the base of the Iola Limestone is chiefly very pale orange, pale-yellowish brown, and medium-gray very fine grained to very finely crystalline fossiliferous limestone but also contains thin beds of medium-gray, black, and some olive-gray shale that is partly limy. Some of the limestone is dolomitic, and some is cherty and oolitic. The chert is generally light gray to medium gray or pale yellowish brown and dense and has white specks.

Iola Limestone--The Iola is 5-25 feet thick and is composed of very pale orange to pale-yellowish-brown dense to very finely crystalline partly fossiliferous limestone. Locally some dolomite of the same color is present at the base.

Lane Shale--The Lane Shale, about 5-20 feet thick, is mainly medium-gray to medium-dark-gray partly limy shale and siltstone. It includes a persistent bed of black shale in its upper part and, locally, a bed of medium-gray argillaceous glauconitic fossiliferous limestone in its lower part.

Wyandotte Limestone--The Wyandotte Limestone, 40-80 feet thick, is light gray, very pale orange, and pale yellowish brown, very fine grained to very finely crystalline, and fossiliferous; it contains a few thin beds of gray shale. In the upper part the limestone is dolomitic and locally very oolitic; in the lower part it contains light-gray to medium-dark-gray dense, in part spicular, chert.

Bonner Springs Shale--The Bonner Springs Shale is 20 to about 100 foot thick and averages about 40 feet in thickness. It consists primarily of medium-gray partly limy and silty shale. At places medium-light-gray very fine to fine-grained limy micaceous sandstone occurs in the upper part.

Lansing Group

The Lansing Group in eastern Shawnee County and vicinity ranges in thickness from about 45 feet to possibly more than 120 feet and averages about 90 feet. The Lansing comprises, in ascending order, the Plattsburg Limestone, Vilas Shale, and Stanton Limestone.

Plattsburg Limestone--The Plattsburg Limestone, about 30-55 feet thick, consists of medium-light-gray and pale-yellowish-brown fossiliferous limestone. The limestone is in part slightly argillaceous and dolomitic; that near the base contains some medium-light-gray to medium-dark-gray dense, in part spicular, chert. Gray shale occurs at places near the base.

Vilas Shale--The Vilas Shale, generally 10-15 feet thick, is mainly medium-gray limy, partly silty shale that in places contains very pale orange slightly argillaceous limestone.

Stanton Limestone--The Stanton Limestone is generally 45-75 feet thick but may be more than 120 feet thick in the Jenkins and Scott Asherman 1 well, in the NE NW NE sec. 28, T. 10 S., R. 15 E. As indicated by the driller's log, the well ended in the Lansing Group and all the Lansing that was penetrated is considered to be Stanton Limestone. The Stanton is principally light-gray, brownish-gray, and very pale orange partly argillaceous fossiliferous limestone, but it includes thin beds of medium- and dark-gray to black shale and siltstone. Fairly thick beds of medium-light-gray very fine to fine grained limy and dolomitic sandstone are locally present in the upper part.

Virgil Series

Douglas Group

Strata between the Lansing and Shawnee Groups were previously divided into the Pedee Group (Missouri Series) and the overlying Douglas Group (Virgil Series). Stanton M. Ball, formerly of the State Geological Survey of Kansas, studied these rocks in detail from Iowa into Oklahoma; his recommended changes in the stratigraphic classification were adopted by the Kansas Survey (O'Connor, 1963, p. 1877, fig. 3). The authors have utilized the entire new classification of rocks between the Lansing and Shawnee Groups except the series and stage names. The U.S. Geological Survey regards the Missouri and Virgil as provincial series in Kansas and does not divide the series of the Pennsylvanian into stages. The State Geological Survey of Kansas classifies the Missourian and Virgilian as stages of the Upper Pennsylvanian Series. Changes in classification adopted in this report are as follows:

  1. The Pedee Group is abandoned in Kansas, and the base of the Douglas Group is lowered to the top of the Lansing Group.
  2. The base of the Stranger Formation (Douglas Group) is lowered to the top of the Stanton Limestone (upper formation of the Lansing Group).
  3. The Iatan Limestone and Weston Shale, formerly formations of the Pedee Group, are reduced to members and are included as the two lower members of the Stranger Formation.
  4. The Lawrence Shale is changed to the Lawrence Formation, and the base is lowered to the base of the Haskell Limestone Member; the Haskell Limestone Member and the overlying Robbins Shale Member were formerly included in the underlying Stranger Formation.
  5. The boundary between the Missouri and the Virgil Series is placed at the base of the redefined Douglas Group.

In eastern Shawnee County and vicinity, the Douglas Group, composed of the Stranger and Lawrence Formations, ranges in thickness from about 180 to 275 feet. It consists predominantly of noncarbonate clastic rock.

Stranger Formation--Sandstone, shale, and siltstone in widely varying amounts and totaling about 75-140 feet thick compose the Stranger Formation (pl. 2). The sandstone is mainly light gray to medium light gray, very fine grained, and micaceous; some is silty, limy, or slightly carbonaceous. The shale and siltstone are commonly gray and olive gray. A thin bed of coal occurs locally in the lower part of the formation.

Lawrence Formation--The Lawrence Formation, about 90-140 feet thick, is chiefly medium-gray shale (pl. 2). The Haskell Limestone Member, at the base, is the most useful key unit in the Douglas Group. This member, which is commonly less than 5 feet thick, is brownish gray, medium-gray, and reddish-brown very fine grained argillaceous limestone. The upper part of the Lawrence includes olive-gray and grayish-red limy shale, medium-light-gray siltstone, and a thin bed of brownish-gray very fine grained silty, dolomitic limestone.

Shawnee Group

The Shawnee, as originally defined as a formation by Haworth (1898, p. 93) from exposures in Shawnee County, Kans., included beds between the top of the Oread Limestone and the top of the Scranton Shale. The U.S. Geological Survey later recognized the Shawnee as a group (Fath, 1921, p. 39); Moore subsequently (1932, p.93-94) redefined the boundaries of the Shawnee to include all beds from the base of the Oread Limestone to the top of the Topeka Limestone.

The Shawnee Group contains, in ascending order, the Oread Limestone, Kanwaka Shale, Lecompton Limestone, Tecumseh Shale, Deer Creek Limestone, Calhoun Shale, and Topeka Limestone.

Oread Limestone (strat. section 1)--The Oread Limestone was originally named by Haworth (1894, p. 123); however, he applied the name to only the lowermost limestone unit (now the Toronto Limestone Member). In 1895 Haworth extended the name to include an overlying thick limestone unit (now the Plattsmouth Limestone Member) and the intervening shales. The thin limestone unit--the Leavenworth--between the thick limestones was not recognized in early reports. Bennett (1896, p. 115) included a very fossiliferous platy limestone as the uppermost unit of the Oread, which was subsequently named the Kereford Limestone Member.

The Oread Limestone is composed, in ascending order, of the Toronto Limestone, Snyderville Shale, Leavenworth Limestone, Heebner Shale, Plattsmouth Limestone, Heumader Shale, and Kereford Limestone Members.

The youngest unexposed rocks in eastern Shawnee County and vicinity compose the Toronto Limestone Member, which consists of very pale orange to pale-yellowish-brown very fine grained to very finely crystalline, in part dolomitic, fossiliferous limestone that is about 10 feet thick.

All members of the Oread except the Toronto Limestone Member crop out in the south wall of the Wakarusa River Valley east of Richland; the Toronto underlies the alluvial fill in the valley. Outcrops are poor, but the limestone members locally form ledges along tributaries of the Wakarusa River. The Oread is about 45 feet thick in this general area; however, only about 35 feet is exposed in the mapped area. In the J. J. Lynn Warner 1 well, about 4 miles northwest of Richland, the Oread is about 65 feet thick. Within the study area the contacts between members of the Oread are conformable.

Snyderville Shale Member--The Snyderville Shale Member was named by Condra (1927, p. 38) for the shale between the Leavenworth Limestone Member and the Weeping Water Limestone Member (Toronto Limestone Member of Kansas) along Heebner Creek east of Snyderville quarry, a few miles west of Nehawka, Nebr.

Exposures of the Snyderville Shale Member are poor, and the basal part does not crop out in the study area. About 3 miles east of the area, in the W NW sec. 29, T. 13 S., R. 18 E., the Snyderville is about 6 feet thick and consists of olive-gray claystone containing many small irregular nodules of very light gray very finely crystalline argillaceous unfossiliferous limestone. Although fossils were not found in the Snyderville in or adjacent to the mapped area, locally in Douglas County (O'Connor, 1960, p. 40) the member contains marine fossils in the upper few feet.

Leavenworth Limestone Member--The Leavenworth Limestone Member was named by Condra (1927, p. 38) for exposures in a roadcut northwest of the Federal Penitentiary at Leavenworth, Kans. The member is composed of medium-gray to medium-dark-gray hard very fine grained limestone and occurs as a single vertically jointed bed about 1.5 feet thick. It weathers to large rectangular blocks, which are medium light gray to moderate yellowish brown. The basal few inches of the Leavenworth is argillaceous and weathers to platy fragments. The upper 0.05 foot is also argillaceous and is stratified owing to the parallelism of fossil fragments. The weathered upper surface of the bed is irregular and pitted. The lower contact appears to be slightly gradational, but the upper contact is sharp and even.

Fossils present throughout the Leavenworth Limestone Member (but more abundant adjacent to the upper and lower contacts) include Osagia, fusulinids, horn corals, crinoid stems, and brachiopods, including Hustedia and Chonetes.

Heebner Shale Member--The Heebner Shale Member was named by Condra (1927, p. 37) for Heebner Creek and the Heebner farm, west of Nehawka, Nebr. The member, about 6 feet thick, is present in southeastern Shawnee County but is not exposed. About 1 mile east of the area, in the NE NW sec. 36, T. 13 S., R. 17 E., Douglas County, the Heebner consists of a lower part of brownish-black to black claystone about 2.7 feet thick overlain gradationally by olive-brown silty claystone 3.1 feet thick. The lower claystone weathers to hard fissile grayish-black to black laminae, and the upper part weathers light gray to light olive gray. Small ellipsoidal gray-brown phosphatic concretions are commonly present in the lower claystone (O'Connor, 1960, p. 41) but were not noted by the authors at the Douglas County locality. Conodonts occur in the black claystone of the Heebner, but no fossils were found in the upper part.

Plattsmouth Limestone Member--The name Plattsmouth was originally applied by Keyes (1898, p. 349-350) to a limestone unit 30 feet thick underlying the Platte Shale and overlying the Lawrence Shale near Plattsmouth, Nebr. This limestone apparently included all units of the Oread Limestone. Condra (1927, p. 37) restricted use of the name Plattsmouth to the thick "Upper Oread" limestone overlying the black shales of the Heebner Shale Member. Moore (1936a, p. 167), however, found that Condra's Plattsmouth also included the Kereford Limestone Member of the Oread and the lower beds of the overlying Kanwaka Shale. Consequently he further restricted the Plattsmouth to the limestone beds between the Kereford Limestone and Heebner Shale Members of the Oread.

The Plattsmouth Limestone Member--the best exposed member of the Oread Limestone--forms a bench in the south wall of the Wakarusa River valley and is well exposed along the north-flowing stream in the SW sec. 27, T. 13 S., R. 17 E. The Plattsmouth is about 16 feet thick in a streambank in the SE cor. NW sec. 27, T. 13 S., R. 17 E.; however, in Douglas County about half a mile southeast of the mapped area it appears to be only about 12 feet thick.

The member is medium-light-gray to medium-gray very fine grained hard dense limestone in thin to medium wavy beds. The individual beds are argillaceous immediately adjacent to the bedding planes and, where weathered, stand out in relief on the outcrop face. Thin layers of olive-gray very calcareous claystone are locally interbedded with the limestone; some layers in the uppermost part of the Plattsmouth are as much as 0.8 foot thick. The limestone weathers light yellowish gray or light gray to moderate yellowish brown. Irregular masses as much as 0.3 foot thick of medium- to brownish-gray dense fossiliferous chert occur in a conspicuous zone about 1 foot thick near the middle of the member. The contact of the Plattsmouth with the underlying Heebner Shale Member is gradational through a few inches of argillaceous limestone or very calcareous claystone.

Algae (Cryptozoon?), crinoid stems, and brachiopods are abundant in the Plattsmouth. Fusulinids are common, and bryozoans and pelecypods occur but are less common.

Heumader Shale Member--The Heumader Shale Member of the Oread Limestone was named by Moore (1932, p. 94, 96). The type locality is in the Heumader quarry in the bluffs above the Missouri River just north of St. Joseph, Mo.

The Heumader Shale Member is very poorly exposed in the Wakarusa River valley in southeastern Shawnee County, where it is present in the dip slope of the bench formed by the Plattsmouth Limestone Member. In an outcrop about half a mile southeast of the mapped area (strat. section 1), the Heumader is about 4 feet thick and consists of weathered light-olive-gray slightly silty claystone that contains many pellets of light-gray argillaceous limestone. The upper 1 foot of the Heumader is medium-gray platy calcareous fossiliferous claystone in the streambank at the southeast corner of the area. Most of the Heumader in this area is virtually unfossiliferous, but Monger (1961, p. 76) found some specimens of Syringopora in the uppermost part at the locality of stratigraphic section 1.

Kereford Limestone Member--Kereford Limestone was the name applied by Condra (1927, p. 45) to one or more lenticular "dense, somewhat arenaceous, in part oolitic and quite fossiliferous" limestones in the lower part of the Kanwaka Shale near both Lecompton and Atchison, Kans., and at Amazonia, Mo. In 1932 Moore (p. 94) classified these beds as the uppermost member of the Oread Limestone. The type locality of the member is the Kereford quarry at the south edge of Atchison, Kans.

The entire Kereford Member is exposed along the stream that crosses the southeast corner of the area. It is partly exposed along the stream in the SE SW sec. 27, T. 13 S., R. 17 E., and an unmapped exposure is in the north bank of the Wakarusa River just downstream from the bridge at Richland.

The Kereford, about 5-7 feet thick, consists of medium-light-gray to medium-gray and light-olive-gray to olive-gray argillaceous wavy very thin to thin-bedded very fossiliferous limestone. Most of the limestone is very finely crystalline, but the lower 2.5 feet and the upper 0.5 foot are very fine grained and contain abundant very small debris of fossils. Generally the limestone weathers to mottled dark yellowish-orange, moderate-yellowish-brown, and light-olive-gray irregular flaggy beds on which well-preserved fossils stand out in relief. The 0.5-foot-thick limestone bed at the top weathers to a hard vertically jointed bed that has abundant fusulinids and small crinoid columnals in relief. A bed of claystone 0.7-1 foot thick underlies the capping limestone bed. The claystone is silty, calcareous, and fossiliferous; it weathers olive gray to olive brown and contains lenses of olive-gray argillaceous very fine grained limestone. The contact with the underlying Heumader Shale Member is poorly exposed, but, where observed, it is sharp and conformable.

The Kereford is characterized by its abundant and diverse fauna, which consists of Osagia, fusulinids, Syringopora, crinoid stems, fenestrate and ramose bryozoans, brachiopods (including Dielasma, Marginifera, Derbyia, Composita, Juresania, Linoproductus, and Hustedia), pelecypods (including Aviculopecten), gastropods, and sparse trilobites. E. L. Yochelson (written commun., 1960) reported on the following forms:

USGS fossil locality 19441-PC (f12989). In streambank in the SE SW sec. 27, T. 13 S., R. 17 E., Shawnee County.

Fusulinids, undet. (abundant)
"Dictyoclostus" portlockianus (Norwood and Prabten)
Neospirifer dunbari R. H. King.

Fusulinids from the upper limestone bed of the Kereford at this locality are retained in USGS foraminiferal collection f12988.

Kanwaka Shale (strat. section 2)--The name Kanwaka Shale was originally proposed by G. I. Adams in an unpublished manuscript (Beede, 1902, p. 163) for the shale between the Oread and Lecompton Limestones. Condra (1927, p. 45) extended the lower boundary to include the present Kereford Limestone and the underlying Heumader Shale Members of the Oread. Moore (1932, p. 94) replaced those limestone and shale units in the Oread, thus restricting the Kanwaka to the present usage. He divided the Kanwaka into, in ascending order, the Jackson Park Shale, Clay Creek Limestone, and Stull Shale Members. The Kanwaka was named for exposures in Kanwaka Township east of Stull, Douglas County, Kans., and is well exposed near the SE cor. sec. 26, T. 12 S., R. 18 E. (Moore, 1936a, p. 169).

All three members of the Kanwaka Shale crop out in the Wakarusa River valley, but to the north only the Stull Shale Member is exposed in the south wall of the Kansas River valley. Exposures are limited to roadcuts and streambanks. The Kanwaka is about 70-80 feet thick in the area. It rests conformably on the Oread Limestone, and the contact is sharp and slightly irregular. The contacts between the members of the Kanwaka also appear to be conformable.

Jackson Park Shale Member--The Jackson Park Shale Member was named by Moore (1932, p. 94); the type locality is Jackson Park, in southeastern Atchison, Kans. The member is about 47 feet thick about 1 mile east of Richland, and is 44 feet thick in the Murchison Federal Land Bank 1 well, about 214 miles southwest of Elmont. The member is mostly sandstone and siltstone but includes some claystone. All the rocks are light olive gray to light olive brown and micaceous. The sandstone is very fine grained and platy to very thin bedded. The silstone and claystone are clayey and silty, respectively, and both are laminated to platy. Some carbonized plant fragments occur on bedding planes in the upper part.

Clay Creek Limestone Member--The Clay Creek Limestone Member of the Kanwaka Shale was named by Moore (1932, p. 94) for exposures on Clay Creek about 1 mile west of Atchison, Kans. The Clay Creek consists of 3-4 feet of medium-gray to medium-olive-gray very finely crystalline argillaceous limestone in very thin to medium beds. The limestone generally weathers to light-olive-gray or yellowish-brown platy fragments and thin rubbly beds, but the lower part locally forms a hard vertically jointed bed. Some medium-dark-gray platy calcareous claystone occurs near the top of the member. Fusulinids are abundant, and crinoid columnals, fenestrate and ramose bryozoans, and shell fragments are fairly abundant.

Stull Shale Member--The upper beds of the Kanwaka Shale--from the Clay Creek Limestone Member to the base of the Lecompton Limestone--were named the Stull Shale Member by Moore (1932, p. 94), Exposures in the SE cor. sec. 26, T. 12 S., R. 18 E., near the village of Stull, Douglas County, Kans., constitute the type locality.

The thickness of the Stull in surface exposures ranges from about 35 feet, southeast of Richland, to about 23 feet, southwest of Richland. Southwest of Elmont the member is about 20 feet thick in the Murchison Federal Land Bank 1 well.

The Stull Shale Member is composed mostly of light-olive-gray to medium-gray laminated to platy micaceous, carbonaceous siltstone and claystone that weather light olive gray and, locally, olive brown. The claystone is silty and is less abundant than the siltstone. Locally, light- to medium-gray very fine grained platy to very thin bedded micaceous sandstone is interbedded with the siltstone. Very small plant fragments in the lower part were the only fossils noted in the member in eastern Shawnee County and vicinity. Just south of the area, in sec. 3, T. 14 S., R. 17 E., Osage County, a few gastropods and pelecypods were found about 8 feet below the top, and a few brachiopods were found at the top (H. G. O'Connor, written commun., 1951).

Lecompton Limestone (strat. section 2)--Bennett (1896, p. 116) applied the name Lecompton to a series of three limestones and the intervening shales that crop out near Lecompton, Kans. Later Condra (1927, p. 45) included a fourth limestone (the Avoca) as the upper unit, and he applied a name to each subdivision. The Lecompton contains seven members, which are, in ascending order, the Spring Branch Limestone, Doniphan Shale, Big Springs Limestone, Queen Hill Shale, Beil Limestone, King Hill Shale, and Avoca Limestone Members.

The Lecompton Limestone crops out in the southeastern part of the area along the Wakarusa River and, to the north, along Deer Creek. The formation also crops out on the south side of the Kansas River; however, it is concealed on the north side by alluvium and glacial deposits. The limestone beds form prominent ledges in the valley walls, but the shale members are poorly exposed.

The formation ranges in thickness from about 40 feet in the Kansas River valley to about 46 feet in the Wakarusa River valley. The Lecompton is about 30 feet thick in the subsurface at the west edge of the area, southwest of Elmont. The Lecompton Limestone conformably overlies the Kanwaka Shale, and the contacts between the members of the Lecompton are conformable.

Spring Branch Limestone Member--The name Spring Branch was applied by Condra (1927, p. 47) to the basal limestone of his Lecompton Limestone Member of the Shawnee Formation. Moore (1932, p. 96) subsequently raised this unit to member status in the Lecompton Limestone of the Shawnee Group. According to Moore (1936a, p. 174), the interbedded thin limestones and shales now placed in the upper part of the Spring Branch were evidently considered by Condra to be part of the overlying Doniphan Shale Member. Because these limestone beds are elements of the same cyclothem as that of the Spring Branch, however, it is preferable to include them with the Spring Branch (Moore, 1936a, p. 174). The type locality is along Spring Branch, north of the village of Big Springs, Douglas County, Kans. The member is also well exposed east of the mapped area in the bluffs west of Lecompton near the NW cor. sec. 35, T. 11 S., R. 18 E., and in a roadcut near the center of the south line of sec. 36, T. 11 S., R. 17 E. (Moore, 1936a, p. 173).

The Spring Branch, about 7.4-14 feet thick, is composed of a lower, ledge-forming limestone unit 5.4-9 feet thick and an upper, less resistant unit of interbedded limestone, claystone, and siltstone about 2-7.5 feet thick. The lower unit is medium-light-gray to light-olive-gray very finely crystalline to very fine grained thick-bedded limestone that generally weathers to light-alive-gray or pale- to moderate-yellowish brown vertically jointed beds. The limestone is generally slightly argillaceous, but the uppermost and lowermost few inches of this unit is locally very argillaceous. In the Wakarusa River valley a very thin light-olive-gray platy calcareous siltstone or claystone parting separates the two units of the member.

Limestone in the upper unit of the Spring Branch is similar to that in the lower unit except that it is very thin to medium bedded and has many interbeds of claystone and siltstone. Locally in the Wakarusa River valley, the limestone at the top is algal and oolitic. On weathering this bed appears to be banded and slightly crossbedded. Abundant minute iron-stained specks give the bed a speckled appearance. The claystone is medium light gray, silty, and platy; the siltstone is light olive gray to light olive brown. Both are calcareous and weather light olive gray, light yellowish orange, and light yellowish brown. Fusulinids are very abundant throughout most of the member, and crinoid columnals are abundant. Osagia is locally very abundant in the upper unit, and gastropods and some ostracodes are common. Fusulinids from the Spring Branch from the locality at the center of the west line of the NW sec. 36, T. 11 S., R. 17 E., about 1 mile east of the area, are retained in USGS foraminiferal collection f12987.

Doniphan Shale Member--The shale between the Spring Branch and Big Springs Limestone Members of the Lecompton was named the Doniphan by Condra (1927, p. 47) from exposures in northern Doniphan County, Kans. In eastern Shawnee County and vicinity, the Doniphan Shale Member is generally deeply weathered and forms a poorly exposed reentrant between the limestone members. The member ranges in thickness from about 2 feet, at the Kansas River, to 6 feet, locally in the Wakarusa River valley.

The Doniphan consists mostly of light-olive-gray and medium- to dark-gray laminated to platy claystone and siltstone that weather light olive gray to medium dark gray and olive brown. The claystone is slightly silty; in the Kansas River valley it is partly carbonaceous and, in some exposures, shows poor fissility. Locally in the Wakarusa River valley, the Doniphan contains pellets less than 0.02 foot in diameter and thin beds of light-olive-gray to medium-light-gray argillaceous unfossiliferous limestone. The Doniphan conformably overlies the Spring Branch; the contact is placed at the top of the stratigraphically highest fossiliferous limestone bed of the Spring Branch. The only fossils noted were small pieces of carbonaceous material in outcrops in the Kansas River valley.

Big Springs Limestone Member--Big Springs is the name applied by Condra (1927, p. 47) to the single thick middle-limestone bed of the Lecompton. The type locality is near Big Springs, Douglas County, Kans., but the member is also typically exposed in a roadcut near the center of the south line of sec. 36, T. 11 S., R. 17 E., about 4.5 miles west of Lecompton (Moore, 1936a, p. 175).

The thickness of the Big Springs Limestone Member ranges from 2 to 3 feet and averages about 2.8 feet. The limestone is light olive gray to medium gray, very finely crystalline, thin to thick bedded, and compact. Locally near Richland a thin olive-gray very calcareous claystone occurs in the lower 1 foot of the member. The limestone weathers to a light-olive-gray to light-gray vertically jointed ledge. At places in the Richland quadrangle, yellowish-orange limonitic spots are abundant on the upper part of the weathered outcrop.

Fusulinids are abundant in the Big Springs, particularly in the lower half, and weather in relief. Osagia, crinoid columnals, bryozoans, and brachiopods are abundant. Fusulinids from the Big Springs from the locality at the center of the west line of the NW sec. 36, T. 11 S., R. 17 E., about 1 mile east of the area, are retained in USGS foraminiferal collection f12986.

Queen Hill Shale Member--The shale above the Big Springs Limestone Member was named the Queen Hill by Condra (1927, p. 46) from exposures at Queen Hill, northeast of Rock Bluff, in T. 11 N., 14 E., Nebraska. The Queen Hill is 2.3-3.6 feet thick near the Wakarusa River, and to the north it is 3.3 feet thick along the Kansas River.

The Queen Hill is composed of a lower unit, slightly more than 1 foot thick, of grayish-black to brownish-black claystone and an upper unit of dark-gray claystone. Both claystones are slightly silty and laminated to platy. The lower unit weathers to dark-gray fissile plates that locally show iridescence; the upper unit weathers olive gray. The basal 0.05-0.1 foot of the lower unit is olive-gray to medium gray silty calcareous claystone that weathers to a light-gray streak at the base of the overlying dark beds.

Conodonts are in the lower unit of the Queen Hill, and plant impressions are scattered throughout the upper unit. Shell fragments are locally abundant at the base of the Queen Hill in the Kansas River valley.

Beil Limestone Member--The Beil Limestone Member, named by Condra (1930, p. 48), overlies the Queen Hill Shale Member and underlies the King Hill Shale Member. The type locality, on the Beil farm, is in the bluffs of the Missouri River at the mouth of Kenosha Creek, south of Rock Bluff, Nebr. (Moore, 1936a, p. 176).

The lower part of the Beil crops out as a prominent ledge, but the upper part is exposed only in streambanks and roadcuts. The Beil, about 8.5-10 feet thick, is predominantly limestone with lesser amounts of siltstone and claystone. The limestone, dominant in the lower 1/2-2/3 of the member, is light olive gray, olive gray, and medium light gray, very finely crystalline to very fine grained, and argillaceous; it occurs in very thin to medium wavy beds. Laminae and very thin layers of olive-gray clayey platy calcareous siltstone are interbedded with the limestone in the lower part. The weathered outcrop is pale yellowish brown to light olive gray and shows the wavy bedding typical of the Beil.

The upper part of the Beil is characterized by alternating thin limestone and claystone beds. The claystone is olive gray to light olive brown, silty, platy, calcareous, and fossiliferous. In the Wakarusa River valley the top of the member is marked in places by a thin limestone bed that contains many dark-yellowish-orange limonitic inclusions, scattered limestone inclusions, and very abundant Osagia algae. The base of the Beil throughout the area is at the stratigraphically lowest fossiliferous limestone bed that overlies the dark-gray claystone of the Queen Hill.

Fossils are abundant in the Beil; fusulinids, crinoids, and brachiopods are the most abundant forms. Fusulinids are very abundant in the lower part but are less abundant to sparse in the upper part. Algae consists of Osagia and Cryptozoon-like forms. Some trilobite fragments were also found. The fauna of the Beil is represented in the following collection reported on by E. L. Yochelson (written commun., 1960):

USGS fossil locality 19442-PC (f12985). In old quarry in the center of the west line of the NW sec. 36, T. 11 S., R. 17 E., about 1 mile east of the mapped area.

Fusulinids, undet.
Stereostylus sp.
Caninoid corals, undet.
Aulopora sp.
Crinoid stem and plate
Echinoid spines
Incrusting bryozoans
Fenestrate bryozoans
Rhomboporoid bryozoans
Derbyia crassa (Meek and Hayden)
Derbyia sp. indet.
Meekella striatocostata (Cox)
Chonetes graulifer Owen
Echinoconchus? sp. indet.
Juresania nebrascensis (Owen)
Reticulatia huecoensis (R. E. King)
Marginifera wabashensis (Norwood and Pratten)
Antiquatonia portlockianus (Norwood and Pratten)
Linoproductus cf. L. prattenianus (Norwood and Pratten)
Cancrinella boonensis (Swallow)
Neospirifer dunbari R. H. King
Composita subtilita (Hall)
Phricodothyris perplexa (McChesney)
"Spiriferina" kentuckensis (Shumard)
Hustedia mormoni Marcou
Dielasma bovidens (Morton)
Astartella sp. indet.
Straparollus (Euomphalus) cf. S. (E.) plummeri Knight

King Hill Shale Member--The name King Hill was applied by Condra (1927, p. 45) to the uppermost shale of the Lecompton from exposures in King Hill southeast of Rock Bluff, Nebr., in T. 11 N., R. 14 E.

The King Hill is about 8 feet thick in the Kansas River valley and about 11 feet thick in the southeastern part of the area. It is mostly olive-gray silty laminated to platy calcareous claystone, but near the middle it contains a thin-bedded unit of very argillaceous limestone 1.5-3.6 feet thick that weathers dark yellowish brown to light yellowish orange. The claystone generally weathers light olive gray, but in places the lower part weathers light greenish gray. Small limestone pellets and nodules occur in the claystone; the pellets in the claystone below the limestone weather light gray, and those above, yellowish brown. The limestone bed contains many fine stringers and small vugs filled with clear or light-brown crystalline calcite. The limestone weathers partly by exfoliation to punky slabs and platy rubble; locally it weathers to boxwork.

The contact between the King Hill Shale Member and the underlying Beil Limestone Member is at the top of the stratigraphically highest fossiliferous limestone that underlies the dark-yellowish-brown punky limestone of the King Hill. In many areas the rocks adjacent to the contact are deeply weathered and the exact position of the contact is difficult to determine.

The King Hill is sparsely fossiliferous. Fusulinids and brachiopods are most abundant near the upper contact. Some ostracodes and foraminifers occur in the upper half of the member in the Kansas River valley just east of the Shawnee County line (Purrington, 1948, p. 44).

Avoca Limestone Member--The upper member of the Lecompton Limestone, the Avoca, was named by Condra (1927, p. 45) from an exposure in South Fork Weeping Water Creek about 3 miles east of Avoca, Otoe County, Nebr. (T. 10 N., R. 12 E.).

The Avoca, 3-4 feet thick, is generally composed of two limestone beds separated by a thin parting of claystone or siltstone. The limestones are light olive gray to medium dark gray and very fine grained. The lower limestone is hard, hackly, and slightly argillaceous; it weathers to a light-olive-gray to pale-yellowish-brown vertically jointed ledge 2-3 feet thick. The upper part of the Avoca is made up of very argillaceous very thin bedded limestone that weathers to platy fragments. The claystone or siltstone is light olive gray and calcareous and locally contains small limestone inclusions that weather yellowish brown.

Fusulinids occur throughout the member and are very abundant in the lower part of the ledge-forming limestone bed. Other fossils include foraminifers, crinoid columnals, ramose bryozoans, brachiopods, pinnacid clams, ostracodes, and some Osagia and Cryptozoon? algae.

Tecumseh Shale (strat. section 3)--The Tecumseh Shale was named by Beede (1898, p. 28) for the thick shale underlying the Calhoun (Deer Creek) Limestone near Tecumseh, Shawnee County, Kans. The shale is well exposed in the SE sec. 36, T. 11 S., R. 17 E. (Moore, 1936a, p. 178). Condra (1930, p. 52-53), on the basis of his work in Nebraska, divided the Tecumseh into three units--the Kenosha Shale, at the base; the Ost Limestone, in the middle; and the Rakes Creek Shale, at the top. Moore (1932, p. 96) extended the usage of these names into Kansas to designate the members of the Tecumseh Shale. Moore, Frye, Jewett, Lee, and O'Connor (1951, p. 66) subsequently decided that the Ost Limestone Member is not persistent enough to warrant any divisions of the Tecumseh in Kansas.

The Tecumseh Shale crops out in the Wakarusa River valley, along Deer Creek at the east edge of the area, and in the bluffs of the Kansas River valley. The formation generally weathers to grass- and tree-covered slopes and is exposed mainly on the steeper slopes and in streambanks. Outcrops in the Kansas River valley are poorly exposed.

The Tecumseh is about 60 feet thick in the Wakarusa River valley and along Deer Creek. Along the Kansas River the formation increases to about 70 feet in thickness and maintains that general thickness in the subsurface north of the river.

The Tecumseh is composed mainly of siltstone and claystone but has some thin beds of sandstone and limestone. The siltstone is light olive gray, pale olive, and medium gray and is laminated to very thin bedded; it weathers to olive-gray to yellowish-brown round, blocky or pencillike fragments that are locally stained reddish brown by iron oxide. The claystone is light olive gray to light olive brown. Both the siltstone and the claystone are finely micaceous and contain fine carbonaceous material. Light-olive-gray to light-olive-brown very fine grained micaceous sandstone occurs in beds less than half an inch thick in the upper part of the formation. A few thin beds of medium light-gray argillaceous limestone are present in the upper part of the Tecumseh in the Wakarusa River and Kansas River valleys. One limestone contains granules and pebbles of light-yellowish-gray to light-olive-gray siltstone.

The basal part of the Tecumseh Shale contains crinoid columnals and a sparse microfauna of foraminifers and ostracodes (Purrington, 1948, p. 44). The remainder of the formation is mostly unfossiliferous except for scattered plant remains. Locally Osagia, crinoid oolumnals, bryozoans, a few Chonetes and other brachiopods, and some poorly presrved casts of pelecypods and gastropods are present in the upper 10 feet.

Deer Creek Limestone (strat. section 4)--The Deer Creek was originally defined by Bennett (1896, p. 117) as the Deer Creek System and included three limestones and the intervening shales. Haworth (1898, p. 94) modified the name to Deer Creek Limestone and included it as a member of the Shawnee Formation. From exposures in Nebraska and adjacent parts of Iowa and Kansas, Condra (1927, p. 50-51) divided the Deer Creek into five units, which are, in ascending order, the Rock Bluff Limestone, Larsh Shale, Haynies Limestone, Mission Creek Shale, and Ervine Creek Limestone. Moore (1936a, p. 183) recognized that the Rock Bluff was the stratigraphic equivalent of the "middle Deer Creek" limestone bed in Kansas and that the "lower Deer Creek" limestone bed in Kansas, which he named the Ozawkie (Moore, 1936a, p. 182), was not then identified in Nebraska. The Haynies Limestone either does not extend southward into Kansas, as was implied by Moore (1936a, p. 187), or it coalesces with the basal part of the Ervine Creek Limestone Member, owing to pinchout of the Burroak (formerly Mission Creek) Shale Member in southeastern Nebraska (Condra and Reed, 1943, p. 48). Condra and Reed (1937, p. 53-54) substituted the name Burroak for Mission Creek. The Deer Creek Limestone of Kansas is composed, in ascending order, of the Ozawkie Limestone Member, Oskaloosa Shale Member, Rock Bluff Limestone Member, Larsh and Burroak Shale Members, and Ervine Creek Limestone Member. The type locality of this formation is along Deer Creek in eastern Shawnee County, Kans.

The Deer Creek Limestone forms a prominent escarpment in the Wakarusa River valley east of U.S. Highway 75 and in the Kansas River valley east of Topeka. The formation also crops out along Rock Creek on the east side of the Meriden quadrangle. The limestone members form ledges, but the shale members are poorly exposed.

The Deer Creek ranges in thickness from about 32 to 43 feet. The contact between the Deer Creek Limestone and the underlying Tecumseh Shale is sharp and conformable; contacts between the members of the Deer Creek are also conformable.

Ozawkie Limestone Member--The first published use of the name Ozawkie was by Condra (1935, p. 12), but Moore (1936a, p. 182) named the Ozawkie Limestone Member for exposures in a roadcut at Ozawkie, in the NE sec. 31, T. 9 S., R. 18 E., Jefferson County, Kans. Previously the Ozawkie had mistakenly been correlated with the Rock Bluff Limestone in Nebraska (Moore, 1932,p, 96).

The Ozawkie Limestone Member is 6-10.1 feet thick and consists of two limestone beds separated (at most localities) by a thin claystone. The limestone is light gray to olive gray and brownish gray to pale yellowish brown, very finely crystalline to very fine grained, compact, and thin bedded to massive. Characteristically the limestone units weather to prominent dark-yellowish-orange to moderate-yellowish-brown vertically jointed ledges. The lower limestone, which is 2.8-6 feet thick, generally weathers to a granular texture because of the fossil debris present. The upper limestone is locally argillaceous and contains small pellets and irregular inclusions of greenish-gray claystone or siltstone, a few granules of light-brown limestone, small vugs filled with calcite crystals, and locally a few very small oolites. The upper bed ranges in thickness from 1.9 to 5.3 feet and has a granular or pseudo-oolitic texture.

The intervening claystone, 0.1-2 feet thick, is light olive gray to olive gray, silty, platy, calcareous, and fossiliferous. It weathers light olive gray to olive brown and contains very small pellets of light olive-gray limestone.

Fusulinids are very abundant in the lower limestone bed and show in relief on weathered surfaces. is also abundant in the lower limestone bed and locally in the upper bed where it occurs along with pelletal algae. Crinoid columnals, echinoids, bryozoans, brachiopods, pelecypods, and gastropods are present in both limestones. Algae are abundant in the following collection from the member, reported on by E.L. Yochelson (written commun., 1960):

USGS fossil locality 19443-PC. In creekbed of south-flowing stream in the SE NW NE sec. 16, T. 11 S., R. 17 E., Jefferson County.

Algae, undet. (abundant)
pelletal Osagia sp. indet.

Oskaloosa Shale Member--The Oskaloosa Shale Member was named by Moore (1936a, p. 184) from exposures near Oskaloosa, Jefferson County, Kans., but the first published use of the name was by Condra (1935, p. 12). The Oskaloosa is 6-8.5 feet thick and is primarily medium-light-gray to medium gray, olive-gray, and light-greenish-gray to dark-greenish-gray slightly silty platy claystone. Locally the member contains sandy very thin bedded siltstone, and in places it has nodules less than 0.05 foot in diameter of light-gray limestone and of very fine grained sandstone.

The Oskaloosa generally is sparsely fossiliferous; crinoid columnals, brachiopods, pelecypods, and gastropods are the main fossils. A few fusulinids occur locally in the uppermost part.

Rock Bluff Limestone Member--The Rock Bluff, which is the middle limestone member of the Deer Creek Limestone in Kansas, was named by Condra (1927, p. 50) from exposures in the bluffs along the Missouri River northeast of Rock Bluff, Nebr. At the type locality the Rock Bluff is overlain by the Larsh Shale Member and underlain by the Tecumseh Shale; however, in Kansas the Oskaloosa Shale and Ozawkie Limestone Members of the Deer Creek separate the Rock Bluff from the Tecumseh.

The Rock Bluff is 1.8-2.8 feet thick and is a medium-light-gray to medium-gray and light-olive-gray very finely crystalline hard compact limestone that has a hackly or subconchoidal fracture. Characteristically the member weathers to a single light-olive-gray to moderate-yellowish-brown vertically jointed bed, although in many places it is thin to medium bedued. Locally the upper surface weathers to platy fragments. Fossils are abundant and include 0sagia, fusulinids, crinoid columnals, brachiopods, and a few mollusks.

Larsh and Burroak Shale Members--The shale above the Rock Bluff Limestone Member in Kansas appears to be the stratigraphic equivalent of the Larsh Shale, Haynies Limestone, and Burroak (Mission Creek) Shale Members of the Deer Creek in Nebraska (Moore, 1936a, p. 187). Condra (1927, p. 49-50) named the Larsh, which overlies the Rock Bluff, from the Larsh farm, on Ervine Creek northeast of Union, Nebr. The Haynies overlies the Larsh in Nebraska but is not recognized in Kansas. The shale overlying the Haynies and underlying the Ervine Creek in Nebraska was originally defined as the Mission Creek Shale (Condra, 1927, p. 49) ; however, because of previous miscorrelation it was renamed the Burroak Shale (Condra and Reed, 1937, p. 53-54). The type locality of the Burroak Shale Member is in roadcuts and ravines near Burr Oak School (E sec. 21, T. 71 N., R. 43 W., Mills County), about 6 miles south of Pacific Junction, Iowa (Condra and Reed, 1937, p. 53).

The Larsh and Burroak, together about 4 feet thick, are dominantly claystone that is readily divided into two units. The lower unit, about 1-2.6 feet thick, consists of medium-dark-gray to black, locally olive black, slightly silty finely laminated to platy claystone that weathers to medium-dark-gray, brownish-black, or dark-olive-gray highly fissile pieces. At many localities the basal part of this unit is calcareous and weathers light olive gray. The upper unit, about 2-3.5 feet thick, consists of light-olive-gray to medium-dark-gray silty laminated to platy claystone and, locally, clayey siltstone that weather medium light gray to olive gray and olive brown. Very small nodules of pyrite, siltstone, and limestone occur in the upper unit at most places. The weathered outcrop of the Larsh and Burroak is conspicuous because of a dark band in its lower part and a lighter colored band in the upper part.

The lower, black claystone unit of the Larsh and Burroak Members contains conodonts, Crurithyris sp. indet., and possibly fish scales (E. L. Yochelson, written commun., 1960). Some pelecypods and possibly orbiculoid brachiopods were noted by the authors. The upper unit of the Larsh and Burroak locally has brachiopods, pelecypods, and a few high-spired gastropods.

Ervine Creek Limestone Member--The upper member of the Deer Creek Limestone, the Ervine Creek, was named by Condra (1927, p. 49) for exposures along Ervine Creek in Cass County, northeast of Union, Nebr. In 1933 Moore and Condra (Condra, 1933, p. 5) included the Jones Point Shale Member and the overlying Sheldon Limestone Member--previously defined erroneously as the lower two units of the overlying Calhoun Shale (Condra, 1930, p. 47)--in the upper part of the Deer Creek Limestone above the Ervine Creek. Condra (1935, p. 11) and Moore (1936a, p. 191) later replaced the lower two units in the Calhoun Shale, thus restricting the Ervine Creek to the present usage.

The Ervine Creek Limestone Member forms the upper part of the Deer Creek escarpment and in many places holds up a separate pronounced scarp. The upper, less resistant part of the member weathers to a gentle slope and is seldom exposed except in quarries. The Ervine Creek ranges from about 13 to 18 feet in thickness and at most localities is divisible into two parts. The lower part, which is the more prominent and widespread and makes up the bulk of the member, is light-olive-gray to olive-gray, or medium-light-gray to medium-gray, dense to very finely crystalline limestone in thin to medium wavy beds. The limestone is very argillaceous adjacent to bedding planes. Laminae and very thin layers of medium-dark-gray very calcareous siltstone and claystone or very silty limestone are interbedded with the limestones at many localities. The lower part of the Ervine Creek characteristically weathers to a light-olive-gray to moderate-yellowish brown ledge in which the wavy bedding is conspicuous (fig. 2).

Figure 2--Typical wavy beds in lower part of Ervine Creek Limestone Member of Deer Creek Limestone in roadcut on U.S. Highway 40 in NW NW sec. 4, T. 12 S., R. 17 E. Pick handle is about 2.5 feet long.

Black and white photo of rock outcrop.

In the upper few feet of the Ervine Creek, the limestone is very argillaceous, and the bedding markedly differs from that in the lower part. This upper limestone is platy to medium bedded, generally not wavy bedded, and weathers to platy fragments or to rounded layers with shallow concave depressions on the surface; in places it is conquinoidal. Siltstone and claystone beds are thicker and more abundant than in the lower part. The limestone either rests directly on limestone of the lower part or is separated from it by a bed of siltstone or claystone.

The Ervine Creek Limestone Member is very fossiliferous, especially in the lower part; locally the upper part is unfossiliferous. Fusulinids are generally present throughout the lower part but are more abundant near the middle; except at a few localities they are sparse in the upper unit. The following collections, reported on by E. L. Yochelson (written commun., 1960), were taken from the Ervine Creek Limestone Member in the mapped area:

USGS fossil locality 19444-PC (f12984). In quarry in the NE SE sec. 16, T. 11 S., R. 17 E., Jefferson County.

Algae, undet.
Fusulinids, undet.
Horn coral, indet.
Rhomboporoid bryozoan
Fenestrate bryozoan
Derbyia crassa (Meek and Hayden)
Linoproductus? sp. indet.
Juresania nebrascensis (Owen)
Productoid brachiopod, indet.
Phricodothyris? sp. indet.
Hustedia? sp. indet.
"Spiriferina" kentuckensis (Shumard)
Bellerophontacean gastropod, indet.
Streptacis crenimarginatus Knight

USGS fossil locality 19445-PC (fl2993). In uppermost part of the member in railroad cut in the NW SW sec. 14, T. 11 S., R. 16 E., Shawnee County.

Osagia? sp. indet.
Fusulinids, undet.
Echinoid spine, indet.
Rhomboporoid bryozoan Derbyia crassa (Meek and Hayden)
Derbyia cf. D. deercreekensis Dunbar and Condra
Productoid brachiopod, indet.
Neospirifer dunbari R. H. King
Composita n. sp?
Spiriferina? sp. indet.
Myalinid pelecypod, indet.
High-spired gastropod, indet.

The locality also yielded the fusulinids in USGS foraminiferal collection f12994, as well as crinoid stems and a dictyoclostid brachiopod. USGS fossil locality 19446-PC (f12983). At stratigraphic section 5.

Fusulinids, undet.
Fenestrate bryozoans
Derbyia cf. D. deercreekensis Dunbar and Condra
Juresania sp. indet.
Linoproductus? sp. indet.
Neospirifer dunbari R. H. King
Composita sp. indet.
Aviculopecten sp.

Calhoun Shale (strat. section 5)--The correlation and nomenclature of the rocks of the Calhoun Shale and the overlying Topeka Limestone in Kansas are intimately related to those in Nebraska. Many changes, summarized in table 1, have been made in both the nomenclature and the position of the contact between the two formations. The problems of correlation of the stratigraphic units in this part of the geologic column between Kansas and Nebraska are complicated by limited exposures, in part due to glacial deposits, geologic structure, and the rapid thinning of the shale units northward into Nebraska.

The Calhoun Shale was originally named the Calhoun Sandstone and Shale by Beede (1898, p. 29) for the beds overlying the Calhoun (Deer Creek) Limestone and underlying the Topeka Limestone. Haworth (1898, p. 94) modified the name to Calhoun Shale. Condra (1927, p. 51) mistakenly placed the Jones Point Shale, Sheldon Limestone, and Iowa Point Shale Members of the Topeka Limestone in the Calhoun Shale in Nebraska, and Moore (1936a, p. 190) concurred in this classification in Kansas. In 1937 Condra and Reed (p. 52) recognized previous errors in correlation and restricted the Calhoun in Nebraska to its present usage as the shale unit between the base of the Wolf River Limestone Member of the Topeka Limestone and the top of the Deer Creek Limestone. Moore, Frye, and Jewett (1944, p. 178) accepted this definition of the Calhoun, although the basal member of the Topeka is called the Hartford Limestone Member in Kansas. This usage has been accepted by the State Geological Survey of Kansas. The type locality of the Calhoun Shale is the "Calhoun Bluffs," on the north side of the Kansas River, in the S. sec. 14, T. 11 S., R. 16 E., a short distance northeast of Topeka.

The Calhoun Shale crops out in the Kansas River valley generally east of Topeka, in the Wakarusa River valley east of Wakarusa, along Deer Creek north of Richland, and along Rock Creek southeast of Meriden. The formation underlies grass-covered and, in places, wooded slopes and is commonly exposed only in stream gullies and roadcuts.

The Calhoun commonly ranges in thickness from about 42 feet along Rock Creek to about 55 feet at its type locality in the Kansas River valley northeast of Topeka. South of the river the formation is about 45 feet thick on Tecumseh Creek at the Kansas Turnpike and about 60 feet thick 2 miles to the south along that creek. Locally, near the east side of the area, in the SE sec. 33, T. 11 S., R. 17 E., the Calhoun is only about 30 feet thick. In the Wakarusa River valley the shale is about 50 feet thick. In the subsurface southwest of Elmont, it is about 40 feet thick.

The Calhoun consists principally of siltstone and sandstone and a small amount of claystone. Some limestone is locally present, and a thin coal bed occurs near the top. Locally sandstone makes up as much as two-thirds of the formation. The siltstone is light olive gray, olive brown, and medium to dark gray, finely sandy, laminated to very thin bedded, and locally micaceous. The sandstone is light yellowish gray, medium light gray, and light olive gray, very fine to fine grained, and generally laminated to thin bedded and locally has finely crossbedded layers. The sandstone contains abundant fine carbonaceous material, particularly on bedding planes and is also commonly micaceous. The weathered sandstone is generally light yellowish gray or light olive brown and, locally, is stained moderate yellowish brown from the ferruginous sandstone layers and concretions. Sandstone is most abundant in the upper part of the Calhoun, where it either is interbedded with siltstone or occurs as thick lenticular channel deposits. These channel sandstones are very conspicuous in the north wall of the Kansas River valley northeast of Topeka.

Claystone is common in the basal and uppermost parts of the Calhoun; locally in the Wakarusa River valley, it makes up more than half of the formation. The claystone is olive gray, medium to dark gray, and locally grayish black; it is silty, laminated to platy, and generally micaceous and locally contains fine carbonaceous material. The claystone weathers light olive gray to medium dark gray and at places has much iron stain on bedding planes.

Beds generally less than 1 foot thick of medium-gray to medium dark-gray very fine grained platy to very thin bedded fossiliferous limestone are in the upper 20 feet of the Calhoun Shale in a small area in the Wakarusa River valley about 1 mile east of Wakarusa. A coal bed about 0.2 foot thick occurs at many localities in the upper 1.5-5.5 feet of the Calhoun Shale.

In general the overlying Calhoun Shale rests conformably on the Ervine Creek Limestone Member of the Deer Creek Limestone, but locally--in the railroad cut in the NW SW sec. 14, T. 11 S., R. 16 E., and in a streambank in the SW NW sec. 15, T. 10 S., R. 17 E.--the uppermost beds of the Ervine Creek have been eroded, and channel sandstone of the Calhoun rests disconformably on them. Locally the contact between the Calhoun and the Deer Creek is gradational. Intraformational channeling of slight magnitude is also evident in the Calhoun Shale, particularly near Topeka.

A sparse fauna of brachiopods, pelecypods, and high-spired gastropods is present in the Calhoun Shale, particularly in the upper part. Carbonized plant fragments are abundant but are too small to identify. Limestone beds in the upper part contain many small shell fragments, and in some beds fusulinids, crinoid columnals, and bryozoans are abundant. Ostracodes are present locally in claystone beds. The fossils in the following list, reported on by E. L. Yochelson (written commun., 1960), were collected about 4 feet above the base of the Calhoun Shale:

Lingula sp. indet.
Aviculopecten sp. indet.
Myalinid indet.
Knightites (Retispira) sp. indet.
Organic indeterminate (possibly Orbiculoidea)

Topeka Limestone (strat. section 6)--The Topeka Limestone--the upper formation of the Shawnee Group--was named by Haworth (1895, plate facing p. 290) and included three limestones and the intervening shales. The nomenclature of the Topeka, particularly of the rock units in the lower part, has been changed many times; these changes are summarized in Table 1. Kirk (1896, p. 80) designated beds apparently equivalent to Haworth's Topeka as the Hartford Limestone from exposures in Coffey County, Kans. Hinds and Greene (1915, p. 188, 189), on the basis of their work in northwestern Missouri, included additional beds stratigraphically higher than those in Haworth's Topeka, but they did not name the various units. Condra (1927, p. 52) divided the Topeka in Nebraska into five units, which are, in ascending order, the Curzen Limestone, Turner Creek Shale, Du Bois Limestone, Holt Shale, and Coal Creek Limestone. Moore (1936a, p. 194) introduced Condra's divisions into Kansas but substituted the name Hartford for the Curzen. That same year Moore (1936b, p. 41) added two additional units to the lower part of the Topeka below the Hartford Limestone Member--the Jones Point Shale, and the Dashner Limestone Members at the base. In a restudy of the Calhoun Shale and Topeka Limestone, Condra and Reed (1937) recognized many miscorrelations of rock units, and they reclassified the beds of the Topeka Limestone into nine members, which are, in ascending order, the Wolf River Limestone, Iowa Point Shale, Curzen Limestone, Jones Point Shale, Sheldon Limestone, Turner Creek Shale, Du Bois Limestone, Holt Shale, and Coal Creek Limestone Members. Except for the use of the name Hartford for the Wolf River and a slight change in spelling of the Curzon, this is the classification of the Topeka now used in Kansas (Moore, Frye, and Jewett, 1944, p. 177-178). The type locality of the Topeka Limestone is near Topeka, Kans., and all the members are well exposed along U.S. Highway 24 in the S sec. 14, T. 11 S., R. 16 E., a short distance northeast of the city.

Table 1--Classification of the Calhoun Shale and the Topeka Limestone in Kansas and Nebraska.

Haworth (1895)Kirk (1986)Gallher (1899)Beede (1898)Haworth (1898)Condra (1927)Condra (1930)Condra (1933)Condra (1935)Moore (1936a)Moore (1936b)Condra and Reed1 (1937)Moore, Frye, and Jewett2 (1944)
FormationBed  FormationFormationMemberFormationMemberBedGroupMemberBedFormationMemberFormationMemberFormationMemberFormationMemberFormationMemberFormationMember
        Topeka limestone Shawnee Topeka limestone Shawnee Topeka limestone Coal Creek limestone Shawnee Topeka limestone Coal Creek limestone Topeka limestone Coal Creek limestone Topeka limestone Coal Creek limestone Topeka limestone Coal Creek limestone Topeka limestone Coal Creek limestone Topeka limestone Coal Creek limestone Topeka limestone Coal Creek limestone
Holt shale Holt shale Holt shale Holt shale Holt shale Holt shale Holt shale Holt shale
Forest City limestone Du Bois limestone Du Bois limestone Du Bois limestone Du Bois limestone Du Bois limestone Du Bois limestone Du Bois limestone Du Bois limestone
Forest City sand rock Turner Creek shale Calhoun shale Iowa Point shale Turner Creek shale Turner Creek shale Turner Creek shale Turner Creek shale Turner Creek shale Turner Creek shale
Topeka limestone Limestone Hartford limestone Curzon's limestone Curzen limestone Sheldon limestone Curzen limestone Hartford (Curzen) Hartford limestone Hartford limestone Sheldon limestone Sheldon limestone
Shale Jones Point shale Jones Point shale Jones Point shale
Limestone Deer Creek limestone Ervine Creek limestone Curzen limestone3 Curzon limestone
Shale Jones Point shale Iowa Point shale Iowa Point shale
Limestone Dashner limestone Wolf River limestone Hartford limestone
      Calhoun sandstone and shale Calhoun shale Calhoun shale Iowa Point shale Calhoun shale   Calhoun shale Iowa Point shale Calhoun shale Iowa Point shale Calhoun shale   Calhoun shale   Calhoun shale  
Meadow limestone Deer Creek limestone Sheldon limestone Sheldon limestone Sheldon limestone
Jones Point shale Jones Point shale Jones Point shale Jones Point shale
1Present usage in Nebraska.
2Present usage in Kansas.
3In 1943 the name was changed to Curzon limestone.

The Topeka Limestone forms a prominent escarpment throughout much of the Wakarusa River and Kansas River valleys. North of the Kansas River the formation crops out mainly in the steep valley walls of Muddy and Rock Creeks. The lower part of the Topeka is the more resistant, and the upper part is seldom exposed except in quarries and roadcuts.

The Topeka ranges in thickness from about 10 feet, in the Wakarusa River valley northeast of Wakarusa, to 33 feet, east of Topeka on the Kansas Turnpike East Exchange Road. The wide range in thickness is the result of erosion of the upper part of the Topeka in the southern part of the area during deposition of the overlying Severy Shale in the northern part. In the Murchison Federal Land Bank 1 well, southwest of Elmont, the limestone is about 28 feet thick.

The Topeka Limestone is composed of nine members, which are, in ascending order, the Hartford Limestone, Iowa Point Shale, Curzon Limestone, Jones Point Shale, Sheldon Limestone, Turner Creek Shale, Du Bois Limestone, Holt Shale, and Coal Creek Limestone Members.

Hartford Limestone Member--The Hartford was named by Kirk (1896, p. 80) from exposures along the Neosho River in Coffey County, Kans., where it apparently included beds stratigraphically equivalent to the Topeka Limestone in the Kansas River valley, as originally defined by Haworth (1895, plate facing p. 290) (now designated as the Sheldon Limestone Member down through the Hartford Limestone Member). In Nebraska this part of the Topeka was designated as the Curzen Limestone by Condra (1930, p. 52), but he later (1935, p. 11) called it Hartford (Curzon). Moore (1936a, p. 196) applied the name Hartford to all beds of the Topeka below the Turner Creek Shale Member. Condra and Reed (1937, p. 6-7) recorrelated the units of the Topeka Limestone in the Kansas River valley and named the lowest limestone unit the Wolf River Limestone Member. In 1944 Moore, Frye, and Jewett (p. 178) changed the name to Hartford. The type locality of the Hartford Limestone Member is near Hartford, Kans., on the Lyon County-Coffey County line. The member is well exposed below the highway bridge at the north edge of town (Moore, 1936a, p. 195).

Over much of the area the ledge formed by the Hartford is the only part of the Topeka exposed. Where the member is concealed, its position is commonly marked by a slight bench on the hillside.

The Hartford ranges in thickness from 3.1 feet along Muddy Creek in sec. 1, T. 11 S., R. 16 E., to 8.2 feet, east of Topeka along the Kansas Turnpike East Exchange Road. The member is predominantly limestone, but it has a thin claystone bed less than 1 foot above its base. The limestone is medium light gray and light olive gray, very fine grained to very finely crystalline, hard, and thin bedded to massive. It is in part slightly silty or argillaceous, particularly in the upper few inches and locally near the base. In a few places the basal bed forms nodular blocks, the upper surfaces of which become platy to rubbly on weathering. The limestone characteristically weathers to small moderate-yellowish-brown subangular or lens-shaped blocks.

The claystone is medium gray to olive gray, silty, laminated to platy, and calcareous. It weathers light olive gray, olive brown, and moderate yellowish brown and forms a reentrant near the base of the Hartford ledge. Locally the claystone grades laterally to slightly sandy siltstone. The average thickness of the claystone bed is about 0.2 foot, but in places it is as much as 3 foot.

The Hartford contains an abundant and varied fauna of algae, fusulinids, lophophyllidid corals, crinoid columnals, echinoderm debris, bryozoans, brachiopods, pelecypods--including possibly Aviculopinna--and high-spired gastropods. The abundance of large fusulinids and large brachiopods facilitates the identification of this unit. The upper 1 foot is generally less fossiliferous, although at many localities it contains abundant Osagia. Fusulinids from the Hartford in stratigraphic section 6 compose USGS foraminiferal collections f12995 and f12999.

Iowa Point Shale Member--The Iowa Point was the name applied by Condra (1927, p. 51-52) to the 10-foot-thick shale underlying the Curzon Limestone Member and overlying the Meadow Limestone Member (now known as the Hartford Limestone Member) in the bluffs above the Missouri River near Iowa Point, Kans., but he mistakenly included this shale as the upper unit of the Calhoun Shale. The Iowa Point was miscorrelated northward into Nebraska by Condra (1930,1935), and southward into the Kansas River valley by Moore (1936a). In 1937 Condra and Rood (p. 7, 51) recognized the true relation of the Iowa Point to the overlying and underlying limestone units, and in 1944 Moore, Frye, and Jewett (p. 178) formally defined the member in Kansas as the shale unit overlying the Hartford Limestone Member and underlying the Curzon Limestone Member of the Topeka. The type locality is in the bluffs above the Missouri River just southeast of the abandoned Iowa Point railroad station in Doniphan County, Kans. (Condra and Reed, 1937, p. 51).

The Iowa Point Shale Member crops out in a narrow and rather inconspicuous reentrant in the escarpment face formed by the lower limestone members of the Topeka Limestone. The thickness of the member averages about 1 foot, but ranges from about 0.1 to 1.5 feet. The Iowa Point is composed of medium-light-gray to olive-gray silty laminated to platy claystone and medium-light- to medium-dark-gray clayey to sandy platy siltstone. Thin beds of light-gray, medium-gray, and olive-gray fine-grained sandstone occur locally. The Iowa Point is generally micaceous and in part calcareous. In some localities the member contains thin beds and lenses of light-olive-gray to medium-light-gray fossiliferous limestone. The Iowa Point is light olive gray to olive gray on weathering.

Crinoids, bryozoans, and brachiopods are the principal fossils in the Iowa Point Shale Member. In places small carbonized plant fragments are abundant. The limestones are the most fossiliferous beds in the member.

Curzon Limestone Member--The name Curzon was originally used by Gallaher (1899, p. 57) in describing those beds in the lower part of the present Topeka Limestone in Missouri that lie below the Forest City Sand Rock (now the Turner Creek Shale Member). Condra (1927, p. 52) applied the name Curzen to beds in the lower part of the Topeka in Nebraska, but later he (Condra, 1935, p. 11) substituted the name Hartford. Condra and Reed (1937, p. 7) correlated the second limestone unit above the base of the Topeka in the Kansas River valley as the Curzen Limestone. This limestone had previously been included by Moore (1936a, p. 196) as an unnamed limestone bed in the Hartford Limestone Member of the Topeka. In 1944 Moore, Frye, and Jewett (p. 178) recognized the validity of the correlation of the Curzon Limestone Member as the unit overlying the Iowa point Shale Member and underlying the Jones Point Shale Member. The correct spelling of the member name as Curzon was decided in 1943. The type locality of the Curzon Limestone Member is east of Curzon Station, southeast of Forest City, Holt County, Mo. (Condra and Rood, 1937, p. 51).

Generally the thickness of the member ranges from about 4.5 to 10.5 feet and averages about 8.5 feet. Locally northeast of Wakarusa, in the SE SW sec. 19, T. 13 S., R. 16 E., the Curzon is only 2.3 feet thick and is overlain by channel sandstone of the Severy Shale. Channel sandstone of the Severy also rests on the eroded Curzon west of Watson in the NW sec. 30, T. 12 S., R. 17 E.

The Curzon is predominantly limestone but has some thin beds of claystone near the middle. At most localities the Curzon is readily divisible into four limestone units, each of which is distinguishable from the others mainly by its weathered color and topographic expression. These units are varied in thickness, however, and their contacts are poorly defined.

The basal unit is medium-gray very finely crystalline very argillaceous limestone that weathers to thin moderate-yellowish-brown rubbly layers; it is generally less than 1 foot thick and at many localities is not distinguishable from the overlying unit.

Overlying the basal unit is a ledge-forming unit of medium-light gray to medium-gray very finely crystalline thin- to medium-bedded, compact limestone. Characteristically the upper 2 feet contains irregular masses of light-yellowish-brown, light-olive-brown, and brownish-gray to medium-dark-gray fossiliferous chert. The limestone is 4.5-6.5 feet thick and weathers light olive gray to moderate yellowish brown.

The third unit, 1-4 feet thick, consists of light-olive-gray and medium-light-gray to medium-gray very finely crystalline argillaceous to silty limestone interbedded with a lesser amount of light-olive-gray to medium-gray calcareous claystone. The limestone beds are very thin to thin, and the claystone is platy to very thin bedded. The mottled light-olive-gray and moderate-yellowish-brown appearance of the weathered rocks and the reentrant formed in the Curzon outcrop aid in distinguishing this unit.

The uppermost unit of the Curzon is 0.7-1.7 feet of light-olive-gray to olive-gray and medium-light-gray very finely crystalline argillaceous compact limestone that weathers moderate yellowish brown and forms a ledge. In places this ledge is vertically jointed, and the upper surface is platy and pitted.

Fossils are abundant in the Curzon and oonsist of algae, fusulinids, crinoid stems, echinoid debris, bryozoans, brachiopods, pelecypods, gastropods, and ostracodes. Fusulinids are abundant in the lower two units of the member, less abundant in the third unit of argillaceous limestone and claystone, and generally scattered in the uppermost limestone unit. Brachiopods and bryozoans are abundant in the middle units, and Osagia is commonly abundant in the upper unit. A composite list of forms from the Curzon Limestone Member in stratigraphic section 6, reported on by E. L. Yochelson (written commun., 1960), is as follows:

Osagia sp. indet.
Osagia? sp. indet.
Fusulinids, undet.
Crinoid plate and stem fragments
Echinoid spines
Rhomboporoid bryozoans
Ramose bryozoans
Fenestrate bryozoans (several genera)
Derbyia sp. indet.
Chonetes granulifer Owen
Neospirifer dunbari R. H. King
Composita subtilita (Hall)
Composita sp. indet.
Linoproductus sp. indet.
High-spired gastropod indet. (aff. "Murchisonia")

Fusulinids from the Curzon in stratigraphic section 6 compose USGS foraminiferal collections f12997 and f12998.

Jones Point Shale Member--The Jones Point was the name applied by Condra (1927a, p. 51) to the shale below the Meadow (Sheldon) Limestone and above his Ervine Creek Limestone units at Jones Point, on the Missouri River east of Union, Nebr., but he mistakenly classified the Jones Point as the lower unit of the Calhoun Shale. Later work at Jones Point (Condra and Reed, 1947, p. 26) showed that this shale is not in the Calhoun and that the upper limestone beds of Condra's Ervine Creek are the Curzon Limestone Member, and therefore, that the Jones Point Shale Member at the type locality is between the Sheldon and Curzon Limestone Members. The correct position of the Jones Point in the Topeka Limestone in Kansas was also determined by Condra and Reed (1937, p. 6); previously Moore (1936a, p. 191) had included this shale in the Calhoun Shale. The type locality of the Jones Point Shale Member is in the bluffs on the west side of the Missouri River at Jones Point, east of Union, Nebr.

Except in a locality about 1.5 miles northeast of Wakarusa and in the vicinity of Bauer Cemetery, about 1.5 miles west of Watson, where the Severy Shale overlies the Curzon Limestone Member, the Jones Point Shale Member apparently occurs throughout the area. Outcrops, however, are limited to roadcuts, streambanks, and quarries.

The Jones Point is 2.4-5.8 feet thick; it is generally thicker in the northern part of its outcrop area. The member is light-olive-gray argillaceous limestone. A few brachiopods and pelecypods were noted locally; however, the member is apparently unfossiliferous in most exposures.

Sheldon Limestone Member--The Sheldon was the name proposed by Condra (130, p. 47) for the limestone bed in the Topeka Limestone that he (Condra, 1927, p. 51) had previously mistakenly correlated with the Meadow Limestone of the Lansing Group in Nebraska. Condra also mistakenly included the Sheldon as the middle unit of the Calhoun Shale above the Jones Point Shale and below the Iowa Point Shale Members. In 1933 Condra (p. 5) transferred the Sheldon Limestone and Jones Point Shale Members to the Deer Creek Limestone, but later both he (Condra, 1935, p. 11) and Moore (1936a, p. 191) returned to the original classification. Fieldwork by Condra and Reed (1937, p. 6) established that the correct position of the Sheldon is below the Turner Creek and above the Jones Point Shale Members; Moore, Frye, and Jewett (1944, p. 177) accepted this classification of the Sheldon for use in Kansas. The type locality of the Sheldon Limestone Member is in the Vilas Sheldon quarry, just east of Nehawka, Cass County, Nebr. (Moore, 1936a, p. 191).

The Sheldon ranges in thickness from 1.2 to 3.5 feet but commonly averages slightly less than 2 feet thick. The member is locally absent northeast of Wakarusa and along Tecumseh Creek west of Watson where the Severy Shale overlies rocks of the Topeka that are stratigraphically lower than the Sheldon.

The Sheldon is composed of light-olive-gray to medium-gray very finely crystalline very thin to thin-bedded hard compact limestone that is argillaceous in the lower 1 foot. It weathers light olive gray, dark yellowish orange and moderate yellowish brown. The lower one third of the member weathers to platy fragments, and the upper two thirds forms a prominent ledge of knobby or tabular blocks. Much of the limestone has a pseudo-oolitic texture because of the small algae present. These textured zones are dispersed in the bed between zones of sublithographic limestone. Near Wakarusa small fragments of chert that weathers yellowish brown occur in the upper part.

The characteristic fossil of the Sheldon is Osagia, which is very abundant. Fragments of crinoids, echinoids, bryozoans, brachiopods, and gastropods are common. Fusulinids are sparse or absent in many areas of outcrop but they are fairly abundant southeast of Meriden and are very abundant in exposures along Rock Creek east of Meriden.

Turner Creek Shale Member--The Turner Creek was named by Condra (1927, p. 52) for the shale underlying the Du Bois and overlying the Curzon Limestone Members. Condra's Curzon apparently included all beds in the Topeka Limestone below the Turner Creek. In Kansas the base of the Turner Creek was placed at the top of the Hartford (Moore, 1936a, p. 197). Condra and Reed (1937) restudied the stratigraphic units in the Shawnee Group in Nebraska and adjacent States and reclassified the Sheldon Limestone Member as the unit underlying the Turner Creek Shale Member. In 1944 Moore, Frye, and Jewett (p. 177) accepted Condra and Reed's classification of the Turner Creek. The type locality of the member is along Turner Creek, southeast of Du Bois, Pawnee County, Nebr., (Condra and Reed, 1937, p. 48).

The Turner Creek Shale Member is 2.7-5.4 feet thick; however, in the areas northeast of Wakarusa, near Berryton, and near Watson, most or all of the member is absent, and the Severy Shale overlies beds stratigraphically lower in the Topeka. In the quarry immediately east of Forbes Air Farce Base, as little as 0.6 foot of the member is present.

The Turner Creek is mainly claystone and siltstone but contains 2-5 thin limestone beds, principally in the middle and upper parts. Most of the claystone and siltstone is light olive gray to olive gray and laminated to very thin bedded. Locally both are slightly sandy and weather to small blocky fragments. At places the weathered claystone fragments are mottled by brownish-gray stain.

The limestone is light olive gray and medium gray to brownish gray, very finely crystalline to very fine grained, partly argillaceous, generally hard and compact, and in beds less than 0.1 foot thick to 0.5 foot thick, Very thin argillaceous limestone lenses occur in the claystone beds at some localities. The limestone is very fossiliferous, and well preserved fossils are common on the upper surfaces of the beds. Thin beds of light-olive-brown silty platy sandstone occur in the Turner Creek near Lake Shawnee.

The limestone beds in the Turner Creek contain abundant brachiopods, gastropods, and pelecypods, as well as some specimens of Osagia, faraminifers (?), crinoid stems, and bryozaans. The claystane and siltstane beds are less fossilferous and contain mostly brachiopods and pelecypods. At a few localities the basal part of the Turner Creek Member cantains abundant ostracodes and some minute carbonized plant remains. E. L. Yochelson (written commun., 1960) reported an the following fossils from this member:

Crinoid stem
Orbiculoidea sp. indet.
Derbyia sp. indet.
Chonetes? sp. indet.
Linoproductus sp. indet.
Juresania? sp. indet.
Numerous productoid spines
Myalinid pelecypod (cf. Myalina (Orthomyalina) sp. indet.)
High-spired gastropod, indet.
Ostracodes, undet.

Du Bois Limestone Member--The Du Bois Limestone Member was named by Condra (1927, p. 52) for exposures along Turner Creek southeast of Du Bois, Pawnee County, Nebr. Complete exposures of the Du Bois are sparse, but the upper part commonly crops out in pastures and on wooded slopes. Erosion during Severy time removed this member from much of the area from Wakarusa northeastward to Watson.

The Du Bois Limestone Member is generally a single vertically jointed bed 0.6-2.4 foot thick of olive-gray, medium-gray, and medium dark-gray hard compact limestone. The limestone is very finely crystalline to very fine grained and locally slightly to very argillaceous. Streaks of dark-gray claystone occur in the upper 0.5 foot at many localities. The member weathers light olive gray, yellowish gray, and light yellowish brown and forms rectangular blocks that are platy at their tops. The rectangular blocks of compact limestone and the position of the member (underlying the black claystone of the Holt Shale Member) are characteristics which facilitate the identification of the Du Bois.

Osagia, bryozoans, brachiopods, pelecypods, and gastropods are abundant in the Du Bois, crinoid stems, echinoid spines, and fusulinids are locally present though not common. At places fossil shells weather in relief along joints.

Holt Shale Member--The thin persistent dark claystone overlying the Du Bois Limestone Member and underlying the Coal Creek Limestone Member was called the Holt Shale Member by Condra (1927, p. 52) frOm the well-exposed rocks just below Forest City and northwest of Oregon, Holt County, Mo.

Exposures of the Holt show a dark band overlain by a lighter colored band. Dark fissile claystone fragments from the lower unit can be readily identified along streams and are thus an aid in locating the outcrop. Most or all of the Holt is missing over a broad area extending from the Osage County line southwest of Wakarusa northeastward to the vicinity of the Kansas Turnpike near the east border of the mapped area.

The Holt Shale Member, 1.7-3.5 foot thick, is composed primarily of claystone in two distinct units. The lower claystone, about 0.6-0.9 foot thick, is mainly medium dark gray to grayish black, but is in part olive gray to olive brown and is laminated to platy. Weathered claystone is fissile and medium dark gray, light olive gray, and dark yellowish brown. The upper, thicker unit is olive-gray to dark-gray slightly silty laminated to platy claystone that weathers light olive gray to olive brown. Along Deer Creek east of Topeka, a few very thin beds of medium-gray very fine grained argillaceous limestone occur in the upper claystone. At several localities near the Kansas River, the entire member is composed of dark-gray partly sandy laminated siltstone.

The lower claystone of the Holt contains some bryozoans, brachiopods, pelecypods, conodonts, and locally, ostracodes. The upper claystone contains abundant bryozoans, brachiopods, and pelecypods.

Coal Creek Limestone Member--The upper member of the Topeka Limestone was originally named the Union Limestone by Condra and Bengston (1915, p. 37), but, because that name was preempted, the name was changed to Coal Creek (Condra, 1927, p. 52). The type locality of the member is along Coal Creek about half a mile north of Union, Nebr.

The Coal Creek Limestone Member is absent from much of the outcrop belt of the Topeka Limestone south of the Kansas Turnpike owing to erosion in Severy time.

The Coal Creek, about 4.5 foot thick, consists of limestone interbedded, with very thin layers of claystone and siltstone. The limestone is light olive gray, locally medium gray, very finely crystalline to very fine or fine grained, and argillaceous to silty, It occurs as very thin to thin beds that weather to nodular or platy fragments. Some limestone beds are composed primarily of shell fragments. The claystone and siltstone are light olive gray to olive gray, and calcareous and occur as beds generally less than 0.05 foot thick; however, a few beds are as much as 0.6 foot thick.

The abundance of fossils--particularly brachiopods--facilitates the identification of this member. The limestone beds contain the large percentage of fossils. Crinoids and ramose, fenestrate, rhomboporoid, and incrusting bryozoans are also abundant; fusulinids are present locally. The Coal Creek Limestone Member contains the following fossils, reported by E. L. Yochelson (written commun., 1960):

USGS fossil locality 19447-PC (f12996). In stratigraphic section 6.

Fusulinids, undet.
Crinoid stems (large pieces)
Fenestrate bryozoans
Rhomboporoid bryozoans
Incrusting bryozoans
Derbyia cf. D. crassu (Meek and Hayden)
Cancrinella boonensis (Swallow)
Juresania nebrascensis (Owen)
Reticulatia huecoensis (R. E. King)
Neospirifer dunbari R. H. King
Composita subtilita (Hall)
"Spiriferina" kentuckensis (Shumard)
Hustedia mormoni (Marcou)

USGS fossil locality 19448-PC. Along the Kansas Turnpike East Exchange Road in NE SW sec. 3, T. 12 S., R. 16 E., Shawnee County.

Crinoid plate, indet.
Incrusting bryozoans
Ramose bryozoans
Juresania nebrascensis (Owen)
Reticulatia huecoensis (R. E. King)
Marginifera wabashensis (Norwood and Pratten)
Neospirifer dunbari R. H. King
Composita subtilita (Hall)
"Spiriferina" kentuckensis (Shumard)
Hustedia mormoni (Marcou)

Wabaunsee Group

The Wabaunsee Group was originally called the Wabaunsee Formation by Prosser (1895, p. 688-697) and defined as the rocks between the base of the Cottonwood Limestone (now the lowest member of the Beattie Limestone of Permian age) and the top of the Osage coal (now the Nodaway coal bed of the Howard Limestone). Haworth (1898, p. 94) placed the base of the Wabaunsee at the top of the Scranton Shale, which is stratigraphically much higher than the Osage coal. Moore (1933, p. 94) redefined the group to include beds from the base of the Americus Limestone Member of the Foraker Limestone to the top of the Topeka Limestone. This change stratigraphically lowered both the upper and lower boundaries of the Wabaunsee. Condra (1935, p. 9) further restricted the Wabaunsee Group by placing its upper boundary at the top of the Brownville Limestone (now the upper member of the Wood Siding Formation); Moore (1936a, p. 200) concurred in this modification. The type locality of the group is Wabaunsee County, Kans.

That part of the Wabaunsee Group exposed in the mapped area comprises, in ascending order, the Severy Shale, Howard Limestone, Scranton Shale, Bern Limestone, Auburn Shale, Emporia Limestone, Willard Shale, Zeandale Limestone, Pillsbury Shale, and Stotler Limestone.

Severy Shale (strat. section 7)--The name Severy Shale was first published by Haworth (1898, p. 66) on the basis of a proposal made by G. I. Adams in his field notes; the formation was named from exposures near Severy, Greenwood County, Kans.

The Severy underlies gently sloping country, but exposures are limited primarily to streambanks, roadcuts, and a few steep slopes. The Severy ranges in thickness from about 30 to 55 feet: near Meriden it is about 45 feet thick; in the subsurface southwest of Elmont, 40 feet thick; northeast of Topeka, 30-35 feet thick; and near the Wakarusa River about 55 feet thick.

The Severy Shale consists mainly of interbedded thin layers of claystone, siltstone, and sandstone, but it locally includes thick channel sandstones. Claystone and siltstone compose the bulk of the formation, but at some localities channel sandstone is the most conspicuous. The claystone and siltstone are generally light olive gray to olive gray and laminated to platy. The claystone is silty, and the siltstone is clayey to very finely sandy and micaceous. Both rock types contain minute particles of carbonaceous material and very small pyritic inclusions that weather moderate yellowish brown. A bed 0.2-1 foot thick light-olive-gray to olive-gray and medium-dark-gray silty to slightly sandy carbonaceous plastic indistinctly bedded claystone commonly occurs at the top of the Severy, in the position of an underclay, just beneath the Nodaway coal bed, which is the basal unit of the Howard Limestone in this area.

The sandstone in the Severy is light olive gray, yellowish gray, and medium dark to dark gray, very fine to fine grained, laminated to very thin bedded, and locally crossbedded. It is silty, micaceous, carbonaceous, and partly calcareous and contains many small pyritic nodules. Medium-light-gray siltstone and dark carbonaceous material commonly occur as fine laminae between the sandstone beds. The sandstone weathers light olive gray, light gray to light brownish gray, and pale to moderate yellowish brown and locally forms thick ledges, some containing large masses of crossbedded sandstone. A typical weathered outcrop of the formation is light olive gray and is covered with small hard yellowish-brown iron-stained fragments of siltstone and sandstone.

Channel deposits of the Severy Shale appear to be primarily sandstone, but some siltstone is present locally. The sandstone is similar in color and bedding to that in the normal stratigraphic sequence but generally is coarser grained and weathers to a pronounced brown color--olive brown, moderate yellowish brown, or reddish brown. The base of a channel deposit is generally evident, but because of poor exposures and the fact that the siltstone in the upper part of many channel fills is similar to that adjacent to the channel, the top could seldom be determined. A complete section of a major channel deposit could not be measured; however, a channel-sandstone unit south of Wakarusa is more than 20 feet thick. Channel deposits are most evident in the lower and uppermost parts of the Severy Shale but probably occur locally throughout the formation.

Except in areas of channeling, the Severy Shale rests conformably on the Topeka Limestone. A broad channel in the lower part of the Severy Shale extends northeastward for about 13 miles from Osage County to near the Kansas Turnpike, in the east-central part of the area (fig. 3). Along Towhead Creek, in the SE NW sec. 35, near the south edge of the area, and along a road in the SE NW sec. 36, T. 13 S., R. 15 E., channel sandstone rests directly on the Holt Shale Member of the Topeka Limestone. To the northeast, in the SE sec. 25, T. 13 S., R. 15 E., the erosion extended into the Jones Point Shale Member of the Topeka; a short distance farther northeast, in the SW sec. 19, T. 13 S., R. 16 E., the channel cut into the lower part of the Curzon Limestone Member. In the quarry just east of Forbes Air Force Base, the basal beds of the channel sandstone rest on strata ranging from the Holt Shale Member downward to wilthin 0.6 foot of the base of the Jones Point Shale Member. Southeast of Lake Shawnee, in secs. 26 and 27, T. 12 S., R. 16 E., the channel appears to have cut stratigraphically down to the top of the Hartford Limestone Member. In a roadcut in the NW NW sec. 30, T. 12 S., R. 17 E., the channel deposits overlie beds of the Curzon Limestone Member. A small channel in the upper part of the Severy Shale is exposed along the Kansas Turnpike in the SE sec. 19, T. 12 S., R. 16 E.

Figure 3--Distribution of channel deposits in Severy and Scranton Shales relative to outcrops of Topeka and Howard Limestones in eastern Shawnee County and vicinity.

Black and white map showing Kansas and Wakarusa rivers, limestone outcrops, and channel deposits.

Finely comminuted carbonaceous material occurs on many bedding planes throughout the formation. Lingula cf. L. carbonari (Shumard) was reported on by E. L. Yochelson (written commun., 1960) from a sandstone bed about 6 feet below the top of the Severy in the SW cor. sec. 22, T. 9 S., R. 17 E., Jefferson County (USGS fossil loc. 19450-PC).

Howard Limestone (strat. sections 7, 8)--The name Howard Limestone was proposed by G. I. Adams in his field notes, but the first published usage of it was by Haworth in 1898 (p. 67). The type locality of the formation is near Howard, in Elk County, Kans., and the member is typically exposed in the NE sec. 7, T. 29 S., R. 11 E. (Moore, 1936a, p. 204).

The Howard in the mapped area is composed, in ascending order, of the Aarde Shale, Church Limestone, Winzeler Shale, and Utopia Limestone Members. (In southern Kansas the basal member of the Howard is the Bachelor Creek Limestone.) Here the base of the Howard is placed at the base of the Nodaway coal bed of the Aarde Shale Member. Where the Nodaway coal is poorly exposed, the base of the Howard was mapped as at the base of the Church Limestone Member, which in most places is 2-4 feet above the base of the coal bed.

The Howard Limestone crops out in a belt that trends diagonally northeastward across the area. South of the Kansas River the Howard forms a distinct bench, but north of the river it is poorly exposed except near Meriden. The Howard is about 11-17 feet thick. The Howard Limestone rests conformably on the Severy Shale throughout the area. At some localities the Howard is partly truncated, and near the southwest corner of the area is locally absent; where the Howard is absent, the overlying Scranton Shale rests on the underlying Severy Shale. The contacts of the members of the Howard Limestone are conformable.

Aarde Shale Member--The name Aarde was applied by Moore (1932, p. 94) to rocks cropping out on the Aarde farm, in sec. 4, T. 26 S., R. 11 E., Greenwood County, Kans. In the type area the Aarde comprises all beds between the top of the Bachelor Creek Limestone Member of the Howard Limestone and the base of the Church Limestone Member, including the very persistent Nodaway coal bed. Where the Bachelor Creek is missing, the Aarde Shale Member is restricted to those beds above the base of the Nodaway. Beede (1898, p. 29) applied the previously discarded name Shunganunga Shale to the few feet of beds between the top of the coal bed and the base of the Church Limestone Member.

The Aarde Shale Member is 0.8-8 feet thick, averaging about 3 foot thick, and consists of the Nodaway coal bed and the overlying claystone or siltstone. The Nodaway coal is brownish black to black and laminated to platy and has a hackly to subconchoidal fracture. Locally the lower part of the coal contains very thin partings of dark-gray to grayish-black finely laminated siltstone or claystone. Exposures of fresh coal are sparse; commonly only a thin coal smut marks the position of this bed. The Nodaway coal bed is 0.2-1.5 feet thick.

Most of the Aarde is light-olive- to dark-olive-gray, medium- to dark-gray, and grayish-black silty laminated to platy claystone. The claystone commonly weathers light olive gray to light olive brown or medium dark gray. A bed of dark-gray and dark-grayish-black to brownish-black claystone that weathers to conspicuous fissile slabs occurs near the middle of the member at many localities. Very thin stringers of coal occur locally above the Nodaway. In a few places the Aarde consists mainly of dusky yellow partly sandy siltstone. Along the Kansas Turnpike in the NW sec. 25, T. 12 S., R. 15 E., the Aarde contains conspicuous lens-shaped bodies of siltstone (fig. 4) that lie 1 foot or more above the Nodaway coal bed. Locally the claystone in the upper part of the member contains small nodules and lenses of light-olive-gray to light-olive-brown clayey fossiliferous limestone. Just west of the area along Sixmile Creek, the Aarde includes several limestone beds about 1 foot thick.

Figure 4--Lens-shaped siltstone deposits (L) in Aarde Shale Member of Howard Limestone along Kansas Turnpike in NW sec. 25, T. 12 S., R. 15 E. Nodaway coal bed (N) at base of cut. Photograph by Ada Swinford, State Geological Survey of Kansas.

Black and white photo of new roadcut along turnpike construction; basal coal bed 3-4 feet thick, siltstone lens is from 0 to 4 feet thick.

Fossils are abundant in the Aarde at some localities and sparse at others. Crinoid stems, horn corals, bryozoans, and brachiopods are very abundant locally, but at other places the only fossils present are plant remains. The Aarde Shale Member includes the following forms, reported on by E. L. Yochelson (written commun., 1960):

USGS fossil locality 19449-PO (f12982). In roadcut in center of sec. 23, T. 10 S., R. 16 E., Shawnee County.

Small forraminifers, undet.
Fenestrate bryozoan fragments
Crurithyris planoconveil!a (Shumard)
"Spirijerina" sp. indet.

Small foraminifers from the Aarde are also in USGS foraminiferal collection f12981, from stratigraphic section 8, and in f12980, from a streambank in the SE SE sec. 2, T. 11 S., R. 15 E., Shawnee County. Additional forms from the Aarde, as reported on by Yochelson, include:

Horn corals, indet. (juvenile)
Crinoid stems, pieces
Orbiculoidea sp. indet.
Crurithyris cf. C. planoconvexa (Shumard)
Composita subtilita (Hall)
Chonetes sp. indet.
Marginifera cf. M. wabashensis (Norwood and Pratten)
Marginifera sp. indet.
Hustedia mormoni (Marcou)
Hustedia sp. indet.
Euphemites sp. indet.
Trilobite pygidium indet.

Church Limestone Member--The Church was named by Condra (1927, p. 54) from outcrops on the Church farm, on Turner Creek southeast of Du Bois, Nebr. The Church is the most resistant bed in the bench formed by the Howard Limestone. The member is 1.1-2.4 feet thick, and the limestone is light olive gray to olive gray and light gray to medium light gray, very finely crystalline, thin to thick bedded, hackly, hard, and compact. It generally weathers light to moderate yellowish brown or light olive gray and forms a single vertically jointed bed that commonly breaks into platy fragments in the upper 0.2-0.5 foot.

Crinoid stems, ramose and fenestrate bryozoans, brachiopods, and, locally, fusulinids and Cryptozoon-like algae are abundant in the Church. The following fossils from the Church Limestone Member were reported on by E. L. Yochelson (written commun., 1960):

USGS fossil locality 19451-PC. In stream in the NW NW sec. 32, T. 10 S., R. 16 E., Shawnee County.

Algae? (Cryptozoan)
Crinoid stems
Fenestrate bryozoan
Chonetes granulifer Owen
Marginifera wabashensis (Norwood and Pratten)
"Spiriferina" cf. "S". kentuckensis (Shumard)
Aviculopecten sp. indet.
Neritacean gastropod, indet.
Ditomopyge? sp.

Yochelson also listed Cryptozoon and "oatmeal (?)," or platelet, algae and ostracodes collected from the Church in a roadcut on the west line of the NW SW sec. 5, T. 10 S., R. 17 E.

Winzeler Shale Member--The Winzeler was named by Moore (1932, p. 94), and the type locality is on the Winzeler farm, in sec. 4, T. 26 S., R. 11 E., Greenwood County, Kans.

The member is 0.9-4.8 feet thick and averages about 3 feet thick. It is principally light-olive-gray silty laminated to platy claystone but includes light-olive-gray finely sandy micaceous siltstone. The claystone and siltstone weather light olive gray to light olive brown, One or more limestone beds as much as 1 foot thick occur mainly in the lower part at several localities. The limestone is light olive gray to medium light gray, clayey, platy to thin bedded, and fossiliferous. It weathers light to moderate yellowish brown and light olive brown. The limestone bed in the basal part of the Winzeler along the Kansas Turnpike in the SE sec. 26, T. 12 S., R. 15 E., is hard and compact and closely resembles the Church Limestone Member. A limestone bed showing cone-in-cone structure occurs locally in the upper 1 foot of the Winzeler near the Kansas River and southeast of Elmont.

Well-preserved fenestrate bryozoans are characteristic of the Winzeler, particularly of the lower part. The member also contains a sparse fauna of crinoid stems, ramose bryozoans, brachiopods, pelecypods, and ostracodes.

Utopia Limestone Member--The Utopia--the upper member of the Howard Limestone--was named by Moore (1932, p. 94), and the type locality is just east of the village of Utopia, in sec. 5, T. 25 S., R. 11 E., Greenwood County, Kans.

The Utopia, about 5-7 foot thick, is composed of a lower unit of limestone and claystone about 4 foot thick and an upper limestone unit 1.5-2 feet thick. The limestone beds crop out locally along streams. Limestone in the lower unit is mainly light olive gray to olive gray, light brownish gray, or medium to medium dark gray and very finely crystalline, to very fine grained. It is argillaceous to silty, locally very finely sandy, and finely laminated to thin bedded. On weathering it becomes light olive gray to light yellowish gray and light olive brown to moderate yellowish brown.

Claystone occurs in beds as much as 0.8 foot thick in the middle and upper parts of the lower unit of the Utopia. The claystone is generally light olive gray, silty, and finely laminated to platy, and weathers light olive gray to light olive brown. Commonly a bed as much as 1 foot thick of dark-grayish-black to brownish-black claystone occurs near the middle of the lower unit. This bed weathers to hard fissile pieces and locally forms a thin ledge.

The upper limestone unit of the Utopia is generally light olive gray, very finely to finely crystalline, silty, platy to very thin bedded, and hard. It weathers light olive gray to light yellowish brown and in many places forms a thin ledge. Locally the uppermost part of the bed weathers to platy fragments, and along a tributary of South Branch Shunganunga Creek in the SE SW sec. 36, T. 12 S., R. 15 E., the upper part weathers to hard concretionary masses 1.0-2.2 feet long and 0.5 foot thick. In a few places the upper unit of the Utopia contains many small subrounded ferruginous concretions that weather moderate yellowish brown.

The abundance of fusulinids and the paucity of other fossils are characteristic of the upper limestone unit of the Utopia. Fusulinids seem to be restricted to the upper unit. Abundant ostraoodes and Osagia are characteristic of the lower limestone and claystone beds, and carbonized plant fragments are common. The Utopia Limestone Member yielded the following fossils, which were reported on by E. L. Yochelson (writtten commun., 1960):

Upper limestone unit

Fusulinids, undet. (abundant). USGS colln. f12992, from stream in the NW NW sec. 32, T. 10 S., R. 16 E., Shawnee County; f13000, from roadcut in the SE cor. sec. 21, T. 9 S., R. 17 E., Jefferson County; and f13001, from roadcut on the west line of the NW SW sec. 5, T. 10 S., R. 17 E., Jefferson County.

Crinoid stems
Fenestrate bryozoans
Rhomboporoid bryozoans
Derbyia? sp. indet.
Composita sp. indet.

Lower limestone unit

USGS fossil locality 19452-PC. In Rock Creek in the NW NW sec. 6, T. 10 S., R. 17 E., Jefferson County.

Linoproductus cf. L. prattenianus (Norwood and Pratten)
Composita sp. indet.
Astartella sp. indet.
Permophorus? sp. indet.
Allorisma? sp. indet.
Knightites (Retispira) cf. K. (R.) nodocostatus (Gurley)
Glabrocingulum sp. indet.
Glabrocingulum? n. sp.
Stegocoelia sp. indet.

The following forms were also collected from this locality but were not retained in the permanent collection:

Algae? ("oatmeal" or pelletal)
Juresania sp. indet.
Linoproductus prattenianus (Norwood and Pratten)
Myalina (Orthomyalina) cf. M. (0.) subquadrata (Shumard)
Ostracodes, undet. (retained but not studied)

Other fossils listed by Yochelson from the Utopia are a bellerophontacean gastropod, a trilobite fragment, and inarticulate brachiopod fragments.

Scranton Shale (strat. sections 8, 9, 10, 12)--The name Scranton was first proposed in 1907 by Bennett for the shale between the underlying Howard Limestone and the overlying Burlingame (now basal member of the Bern Limestone) , according to Haworth and Bennett (1908a, p. 82); the name replaced the term "Burlingame Shale" that was previously applied to that stratigraphic unit. Moore (1936a, p. 210) discarded the name Scranton and raised the members of the Scranton to formational rank. In 1956 Moore and Mudge (p. 2277) reintroduced the Scranton Shale as a formation. The name is derived from Scranton, Osage County, Kans., but, as no type section was designated when the formation was defined, Moore and Mudge (1956, p. 2277) designated a reference section along an eastward-flowing stream in the center of sec. 34, T. 12 S., R. 15 E., Shawnee County. The lower part of the formation, however, is not exposed at this locality.

The Scranton Shale comprises, in ascending order, the White Cloud Shale, Happy Hollow Limestone, Cedar Vale Shale, Rulo Limestone, and Silver Lake Shale Members. The Happy Hollow and Rulo were mapped in areas of good exposures, but they were not traced across the entire outcrop belt of the Scranton.

The lower part of the Scranton underlies low rolling country, and exposures commonly are poor. Generally the upper part is exposed in gullies in the steep slope of the escarpment capped by the overlying Bern Limestone.

The Scranton is about 140 feet thick west of Forbes Air Force Base. About 130 foot of the formation was measured in the south bluff of the Kansas River valley just west of the mapped area. The shale is 165 feet thick in the Murchison Federal Land Bank 1 well, southwest of Elmont. The Scranton is about 145 feet thick in a well just north of the mapped area about 2.5 miles northwest of the village of Rock Creek.

The formation is composed mainly of claystone and siltstone but includes a lesser amount of sandstone and some limestone. Throughout most of the area the Scranton Shale rests conformably on the Howard Limestone; however, channeling in the White Cloud Shale Member of the Scranton has locally removed part or all of the Howard. The contacts between the various members of the Scranton apparently are conformable.

White Cloud Shale Member--The White Cloud Shale Member, as originally defined by Condra (1927, p. 58), included all beds from the top of the Howard Limestone to the base of the Rulo Limestone Member and contained, in the upper part, the Happy Hollow Limestone Member. In 1930 Condra (p. 53) restricted the White Cloud to the beds between the Howard and the base of the Happy Hollow. The type locality is west of White Cloud, Doniphan County, Kans.

A complete section of the White Cloud was not measured in the area, but the thickness of the member is estimated to be 80-105 feet. More than 40 feet of the lower part of the member is exposed on the south side of the Kansas River valley in secs. 27 and 28, T. 11 S., R. 15 E.

The White Cloud is principally light-olive-gray to olive-gray and medium-gray silty platy claystone and light-olive-gray, light brownish-gray, and medium-gray to medium-dark-gray sandy laminated to very thin bedded siltstone. Locally, light-gray to light-olive gray fine-grained platy to very thin bedded sandstone constitutes a large percentage of the member. The sandstone is commonly micaceous and contains much finely comminuted carbonaceous material. In places the claystone and siltstone contain many small medium-dark gray very fine grained hard compact sideritic concretions and pellets of pyrite; both the concretions and pellets weather moderate yellowish brown. Outcrops of the White Cloud are generally light olive gray to light olive brown. The outcrop is commonly broken by many very thin vertical fractures filled with siltstone that weathers to hard moderate-yellowish-brown chips.

Channel deposits in the White Cloud Shale Member are exposed at four localities, and others are undoubtedly present in the area but concealed. In some places near the southwest corner of the area, channeling has removed all the Howard Limestone, but in other places small remnants of the Church Limestone and Aarde Shale Members of the Howard remain. The channel appears to trend from Sixmile Creek in secs. 21 and 22, T. 13 S., R. 15 E., southward into Osage County (fig. 3). The west limit of the channel is roughly delineated by outcrops of the Howard Limestone; the east limit is not known but was probably east of Sixmile Creek. Outliers of the lower part of the Howard in the center of sec. 34, T. 13 S., R. 15 E., are apparently located within or close to the edge of the channel. The channel fill appears to consist primarily of interbedded claystone and sandy siltstone. Where the Howard Limestone is absent, the deposit could not be distinguished from similar beds in the upper part of the Severy Shale. The contact between the Scranton and Severy Shales was arbitrarily drawn on the map at the projected horizon of the base of the Howard Limestone.

A channel in the basal part of the White Cloud is excellently exposed along the south side of the Kansas River valley in the W2 sec. 27 and along the east edge of sec. 28, T. 11 S., R. 15 E. At the east end of the exposure, the base of the channel is about 22 feet above the top of the Howard Limestone; however, to the west the channel cuts to within 1 foot of the base of the Utopia Limestone Member of the Howard. Locally the base of the channel is marked by conglomeratic limestone as much as 1 foot thick composed of subangular to subrounded pebbles of weathered olive-gray to moderate-yellowish-brown hard compact very finely crystalline limestone in a matrix of light-olive-gray sandy micaceous limestone. The bed contains much pyrite and carbonaceous material, and a very thin coal stringer locally occurs at or near the base. In the deepest part of the channel a unit 15 feet thick of interbedded olive-gray sandy platy siltstone and very fine grained silty platy to medium-bedded sandstone directly overlies the conglomerate. Many very small mudstone chips occur on the bedding planes. Above this unit is more than 25 foot of very light gray to light-gray fine-grained calcareous sandstone in ledge-forming beds as much as 6 foot thick. The sandstone contains much mica and carbonaceous material. In this exposure the channel fill is overlain by sandstone that is stratigraphically higher in the White Cloud and that contains many thin discontinuous conglomerates composed mainly of ironstone fragments.

North of the Kansas River a channel in the basal part of the White Cloud is exposed in a roadcut in the NE cor, sec. 11, T. 11 S., R. 15 E. The base of the channel is marked by a conglomerate as much as 1.2 feet thick. The conglomerate is composed of pebbles and small cobbles of sideritic ironstone that weathers dark reddish brown and moderate yellowish brown and of granules and pebbles of light-greenish-gray claystone, embedded in a matrix of very fine grained sandstone containing much pyrite and carbonaceous material. This conglomerate lies about 12 feet above the top of the Howard Limestone. The rest of the exposed channel fill is interbedded laminated to very thin bedded siltstone and sandstone.

The channel deposit in the basal pari of the White Cloud exposed in a streambank ()If Rock Creek north of Meriden in the NW NW sec. 6, T. 10 S., R. 17 E., rests on the lower limestone unit of the Utopia Limestone Member of the Howard Limestone. The channel fill is made up of light-gray to light-yellowish-gray fine- to medium-grained very thin to thin-bedded sandstone which is very micaceous and contains much carbonaceous material. A very thin conglomeratic sandstone containing sub angular 'pebbles of light-olive-gray dense ironstone that weathers dark reddish brown to moderate yellowish brown occurs ,a,t the base of the channel. Fossils are sparse in the White Cloud and are mainly carbonized plant remains; 'also, a few small pelecypods occur in the basal 1 foot.

Happy Hollow Limestone Member--The Happy Hollow was named by Condra (1927, p. 58), who included it as a bed in the White Cloud Shale Member. In 1930 Condra (p. 53) placed the top of the White Cloud at the base of the Happy Hollow, and recognized the Happy Hollow as a separate unit of the Scranton Shale, Moore (1936a, p. 209) discarded the name Scranton Shale and considered the Happy Hollow to be a formation, but later he and Mudge (1956, p. 2277) reintroduced the name Scranton Shale and included the Happy Hollow as a member. The type locality is in the bluffs at the mouth of Happy Holly Creek, in northeastern Doniphan County, Kans.

Outcrops of the Happy Hollow Limestone Member are sparse. The member was mapped with certainty only near the Kansas Turnpike close to the west edge of the area, where it crops out in streambanks and roadcuts. The Happy Hollow was not definitely recognized north of the Kansas River.

The Happy Hollow Limestone Member, 0.3-0.6 foot thick, is brownish gray to medium gray, very fine to fine grained, and very argillaceous to sandy. Commonly it weathers to moderate- to dark-yellowish-brown rough pitted cobbles; however, in some exposures it breaks into platy fragments. Locally the upper surface appears brecciated, and the bed contains many small masses of ferruginous limestone. A bed about 3.2 feet thick of light-olive-gray to olive-gray very argillaceous very thin to thin-bedded limestone, which may be equivalent to the Happy Hollow, caps a small hill in the NW cor. SW sec. 35, T. 9 S., R. 16 E. The bed weathers light olive gray to moderate yellowish brown and contains many coaly and carbonaceous plant remains and, also, abundant Chonetes, Marginifera, and other brachiopods, crinoid stems, and gastropods. South of the Kansas River the member contains many crinoid stems, ramose bryozoans, small brachiopods, and pelecypods.

Cedar Vale Shale Member--The Cedar Vale was named by Condra (1930, p. 53) from exposures east of Cedar Vale, Chautauqua County, Kans. Moore (1936a, p. 212) stated that it is exposed in the east bluff of the Caney River in sec. 12, T. 34 S., R. 8 E.

The Cedar Vale is about 30-35 feet thick in the vicinity of the Kansas Turnpike near the west edge of the area. The complete thickness of the member north of the Kansas River could not be determined. In the Murchison Federal Land Bank 1 well, southwest of Elmont, the combined thickness of the Cedar Vale and White Cloud Shale Members is about 140 feet.

The Cedar Vale is primarily siltstone and some claystone. Both rocks are mainly light olive gray and medium light to medium gray and laminated to platy and weather light olive gray and light olive brown to moderate yellowish brown. The claystone is silty, and the siltstone is clayey to sandy, micaceous, and in part calcareous. In a few localities thick beds of light-olive-gray to medium-dark-gray very fine grained platy to very thin bedded sandstone occur in the member, but generally sandstone makes up only a small part. A few thin beds of brownish-gray fine-grained argillaceous fossiliferous limestone are also present.

A coal bed about 0.3 foot thick--the Elmo--occurs in the upper 1 foot of the Cedar Vale at most localities south of the Kansas River. The coal was not seen in outcrops north of the river, probably because of poor exposures; but a coal bed correlated with the Elmo was cut by the Murchison Federal Land Bank 1 well, southwest of Elmont.

Crinoid stems, fenestrate bryozoans, small brachiopods, pelecypods, and gastropods are locally abundant in the Cedar Vale, particularly in the limestone beds and in the beds above the Elmo coal. Well-preserved plant leaf and stem imprints are present on many bedding planes in the upper part.

Rulo Limestone Member--The Rulo was originally defined by Condra and Bengston (1915, p. 14) as the lowest member of the Nemaha Formation. Later Condra (1927, p. 58) considered the Rulo to be in the upper part of the Scranton Shale. Moore (1936a, p. 213) discarded the name Scranton Shale and raised the shale members--including the Rulo--to formational rank. Later he and Mudge (1956, p. 2277) returned to the usage of Condra, in which the Rulo is considered to be a member of the Scranton. The type locality is about 2.5 miles north of Rulo, Richardson County, Nebr.

The Rulo was mapped only in the southwestern part of the area and in a small area north of the Kansas River southwest of Elmont, Exposures are generally confined to streambanks and roadcuts. In places the Rulo forms a minor bench on the hillside, and hard limestone fragments are scattered on the outcrop. In the southwestern part of the area, the Rulo is 1.4 feet thick. North of the Kansas River the Rulo, apparently mostly limestone concretions, is only 0.2-0.4 foot thick; in a streambank in the SE SE sec. 15, T. 10 S., R. 15 E., it is locally 4.1 feet thick.

The Rulo is olive-gray and medium-gray to medium-dark-gray very finely crystalline silty hard fossiliferous limestone that weathers light olive gray, light olive brown, or moderate yellowish brown. The upper and lowermost beds are very argillaceous and weather to platy fragments. Part of the Rulo weathers to hard concretions that have subconchoidal fracture. In much of the northern third of the area, a bed of concretions occurs about 20 feet below the top of the Scranton Shale and appears to be stratigraphically equivalent to the Rulo. The concretions are composed of silty limestone, are in part septarian, and have veins of light-gray and dark-brown calcite.

Brachiopods are generally abundant in the Rulo and are particularly evident on the surface of the limestone concretions. Crinoid stems, bryozoans, pelecypods, and gastropods are also common. The following is a list of fossils, by E. L. Yochelson (written commun., 1960), from the Rulo Limestone Member:

USGS fossil locality 19453-PC. In streambank in the SE SE sec. 15, T. 10 S., R. 15 E., Shawnee County.

Crinoid stems
Fenestrate bryozoans
Chonetes granulifer Owen
Reticuatia huecoensis (R. E. King)
Marginifera cf. M. wabashensis (Norwood and Pratten)
Neospirifer dunbari R. H. King
Composita sp. indet.
Hustedia mormoni (Marcou)
Astartella sp.

These additional forms were also identified from the member by Yochelson:

Rhomboporoid bryozoans
Linoproductus prattenianus (Norwood and Pratten)
Linoproductus sp. indet.
Pelecypod, indet.
Platyceras sp. indet.
Low-spired gastropod, indet.
Cf. Donaldina indet.
Ostracodes, indet.

Sllver Lake Shale Member--The Silver Lake, as originally defined by Beede (1898, p. 30), included the beds from the top of the Elmo coal bed (now defined as part of the Cedar Vale Shale Member) to the base of the Burlingame Limestone Member of the Bern Limestone; the Rulo Limestone Member was included in this unit. Condra (1927, p. 58) applied the name Silver Lake only to the beds between the top of the Rulo Limestone Member and the base of the Burlingame Limestone Member and designated the shale as the upper unit of the Scranton Shale, Moore (1936a, p. 214) discarded the name Scranton Shale and considered the Silver Lake to be a formation; however, he and Mudge (1956, p. 2277) later reintroduced the name Scranton Shale and included the Silver Lake as its upper member. The type area is near Silver Lake, Shawnee County, Kans.

The Silver Lake Shale Member crops out in the slope directly below the escarpment formed by the Bern Limestone and is the best exposed part of the Scranton Shale. The Silver Lake, about 19-26 feet thick, is composed of various proportions of interbedded claystone, siltstone, sandstone, and some limestone. In general, claystone is the principal rock, and siltstone and sandstone occur in roughly equal, but lesser, amounts. The claystone and siltstone are mainly light olive gray and medium light to medium dark gray and are generally laminated to platy. On weathering they become light olive gray, light gray, olive brown, and moderate yellowish brown. The claystone is silty and partly calcareous and in places contains thin lenses of limestone. The siltstone is clayey to sandy and generally micaceous. Locally the lower part of the member contains dense limestone concretions.

Sandstone in the Silver Lake is light olive gray to medium light gray, very fine grained, silty, micaceous, platy to thin bedded, and locally massive. Some layers show indistinctly formed crossbedding. A thick bed of sandstone occurs 5-8 feet below the top of the member northwest of Meriden. The sandstone forms a prominent face more than 13 feet high in the side of a butte in the SW NW sec. 2, T. 10 S., R. 16 E.

Limestone beds as much as 3 feet thick are common in the upper part of the member but also occur locally in other parts. The limestone is generally light olive gray to olive gray or brownish gray, very finely to finely crystalline, and silty. It is very thin to thin bedded, locally forms hard compact concretions, and weathers light olive gray, olive brown, or dark yellowish brown.

Fossils in the Silver Lake Shale Member occur primarily in the limestone beds and include mainly crinoid stems, brachiopods, pelecypods, gastropods, and some specimens of Osagia and other algae, some plant fragments are also present. E. L. Yochelson (written commun., 1960) reported on the following fossils collected by the authors:

USGS fossil locality 19454-PC. In roadcut in the center of the W2 W2 sec. 26, T. 9, S., R. 16 E., Jackson County.

Algal growth (coating shells)
Myalina (Orthomyalina) subquadrata Shumard
Euphemites vittatus (McChesney)

USGS fossil locality 19455-PC. In stratigraphic section 12.

Crinoid stems
Echinoid plates
Brachiopod fragments, indet.
Bellerophon (Pharkidonotus) percarinatus (Conrad)
Paleostylus (Pseudozygopleura) sp. indet.
Ostracodes, undet.

Bern Limestone (strat. sections 10, 11, 12)--The Bern Limestone was named by Moore and Mudge (1956, p. 2276-2277) and defined as the beds overlying the Scranton Shale and underlying the Auburn Shale. The formation is named after the town of Bern, in northern Nemaha County, Kans., and the type section is in a roadcut in the SE SE sec. 7, T. 1 S., R. 13 E., about half a mile north and 1 mile west of Bern. The Bern Limestone comprises, in ascending order, the Burlingame Limestone, Soldier Creek Shale, and Wakarusa Limestone Members.

The Bern Limestone caps outliers and forms a prominent escarpment south of the Kansas River along the west edge of the area, north of the river near Elmont, and northwest of Meriden. The limestone members form benches, which are separated by the covered slope underlain by the shale member.

In eastern Shawnee County and vicinity the Bern ranges in thickness from about 12 to 24 feet; it attains maximum thickness near Elmont. The Bern Limestone rests conformably on the Scranton Shale, and at most localities the contact is sharp and even. A transitional zone a few inches thick of very argilaceous limsetone or very calcareous claystone occurs locally. The contacts between the members of the formation also are conformable.

Burlingame Limestone Member--The name Burlingame was applied by Hall (1896, p. 105) to the thick limestone that directly overlies the Scranton Shale. Moore and Haynes (1917, p. 106) classified the Burlingame as a member of the Wabaunsee Formation. Later Moore (1936a, p. 200-215) raised the Wabaunsee to group rank and included the Burlingame as a formation. Moore (1936a, p. 215-216) also pointed out that the overlying Soldier Creek and Wakarusa had previously been included by various authors in the Burlingame, but he restricted the Burlingame to include only the lower limestone, seemingly in accord with Hall's original description, In 1956 Moore and Mudge (p. 2277) classified the Burlingame as the lower member of the newly defined Bern Limestone. The type locality is in Burlingame, Kans., where the member forms a fairly prominent escarpment through the western part of town.

Thickness of the Burlingame Limestone Member varies markedly from place to place. At the north edge of the area, north of Meriden, the Burlingame is only 1.6 feet thick, but along U.S. Highway 75 in the SE cor. sec. 31, T. 9 S., R. 16 E., it is 11.8 foot thick.

The Burlingame is generally a single bed composed of two distinct limestone lithologies. Over much of its outcrop area north of the Kansas River, it is composed of irregular, generally elongate, subangular to subrounded fragments of light-gray to light-olive-gray very finely crystalline hard compact sparsely fossiliferous limestone in a matrix of very fine grained argillaceous compact limestone (fig. 5). The fragments may be jumbled or arranged in irregular layers and are generally alined with the convex side down (fig. 6). They have subconchoidal fracture, and each is generally partly rimmed with a dark very thin algal (?) layer. The fragments weather dark yellowish brown, the matrix weathers pale yellowish orange to pale yellowish brown, and the outcrop is generally mottled light olive gray to moderate yellowish brown. The limestone is in thin to medium uneven beds.

Figure 5--Brecciated part of Burlingame Limestone Member of Bern Limestone in quarry in NW SE sec. 14, T. 10 S., R. 15 E. Note dark algal (?) layer beneath limestone fragments. Light-colored matrix of very fine grained limestone. Vertical peel print, x 2, courtesy of D.E. Owen.

Black and white close-up pphoto of limestone.

Figure 6--Weathered brecciated part of Burlingame Limestone Member of Bern Limestone in roadcut in NW NE sec. 36, T. 10 S., R. 14 E., about 3 miles west of mapped area.

Black and white photo of very rectangular outcrop, about 1 foot high.

In areas where the Burlingame shows little or no brecciation, as south of the Kansas River, northwest of Meridian, and at localities southeast of Hoyt, the limestone is generally light olive gray and medium light gray to medium gray, very finely crystalline, slightly argillaceous, thin to thick bedded, hard, compact, and very fossiliferous. Locally the lower 0.2 foot is more argillaceous and weathers to rubble. Where both limestone lithologies occur in the same outcrop, the brecciated limestone always forms the upper part.

At several localities a light-gray silty very calcareous claystone is present in the lower 1 foot of the Burlingame. The upper and lower contacts of the claystone are uneven and gradational, and laterally this unit probably grades to limestone. The claystone is poorly exposed in the SE cor, sec. 31, T. 9 S., R. 16 E., where it is 0.8 foot thick, and is well exposed in a roadcut in the SE SW sec. 34, T. 10 S., R. 15 E., where it is 0.2 foot thick.

Fossils are common but not abundant in the brecciated part of the Burlingame, and abundant in the nonbrecciated part. Fusulinids and Osagia are particularly abundant in the nonbrecciated part. In places small gastropods are abundant in the basal part of the member. The Burlingame Limestone Member includes the following fossils, reported on by E. L. Yochelson (written commun. 1960):

Osagia (or a similar algal growth)
Fusulinids, undet. (abundant)
Dibunophylloides sp.
Crinoid stems
Echinoid spines
Fenestrate bryozoan fragments
Rhomboporoid bryozoans
Neospirifer dunbari R. H. King
Composita subtilita (Hall) Derbyia crassa (Meek and Hayden)
Chonetes granulifer Owen
Chonetes sp. indet.
Linoproductus sp. indet.
Productid brachiopods, indet.
Enteletes? sp. indet.
Abundant shell fragments, indet.

Fusulinids from the Burlingame are retained in the following USGS foraminiferal collections: f12976, from stratigraphic section 10; f12978, from a roadcut on the west line of the NW SW sec. 19, T. 9 S., R. 17 E., Jefferson County; and f12979, from a railroad cut in the SE SW sec. 2, T. 10 S., R. 15 E., Shawnee County.

Soldier Creek Shale Member--The name Soldier Creek was applied by Beede (1898, p. 30) to the shale between the top of his Stanton Limestone and the base of his Wakarusa. According to Moore (1936a, p. 219), however, Beede's original Wakarusa Limestone is the unit now called the Reading Limestone Member of the Emporia Limestone, and the Wakarusa Limestone Member of the Bern Limestone of the present usage was in the upper part of Beede's Stanton Limestone. Condra (1927, p. 77) unintentionally transposed the name Wakarusa to the first limestone above the top of the Burlingame and designated as the Soldier Creek the shale between the two limestones. Condra's usage had widespread application, and Moore (1936a, p. 218-220) recognized the error of the correlations with the Wakarusa and the Soldier Creek at their type areas but argued that usage rather than priority should be followed in applying names to those two units. Thus the present application of the names Wakarusa and Soldier Creek is modified from that of Beede, but the sequence of units is the same, No type locality for the Soldier Creek Shale Member was designated, although Moore (1936a, p. 218) stated that it is presumably on Big Soldier and Little Soldier Creeks about 3 miles from Silver Lake, Shawnee County, Kans. (west of the mapped area).

In the Soldier Creek, pronounced differences in thickness occur within short distances; the range in thickness is from 2.6 to 15,2 feet. Southwest of Elmont the Soldier Creek is 7.4 feet thick in a quarry in the NW sec. 26, T. 10 S., R. 15 E., but it abruptly thickens to 15.2 feet in a quarry in the northeast quarter of the section. The Soldier Creek is thinnest in the NE cor, sec. 6, T. 10 S., R. 16 E., where the Burlingame Limestone Member attains its maximum thickness.

The Soldier Creek is composed mainly of claystone, but one or two beds of limestone are generally present in the middle or upper parts. The claystone is typically light olive gray to olive gray and medium gray; however, some is light greenish gray and medium dark gray to dark gray. It is partly silty, laminated to platy and partly calcareous and weathers to shades of olive gray mottled with light olive brown, Some very calcareous claystone weathers to yellowish-orange boxwork.

Limestone of the Soldier Creek is mainly light olive gray and medium light gray, very finely crystalline, very argillaceous in part, and very thin to medium bedded. Some beds are coquinoidal; others are dense very argillaceous unfossiliferous limestone that weathers to olive-gray or yellowish-orange rubble, some of which is nodular or cellular.

Locally along the Kansas Turnpike, moderate-yellowish-orange to dark-yellowish-orange and moderate-yellowish-brown very fine grained silty sandstone is present in the upper part of the member and is interbedded with siltstone in the lower part. A very thin streak of coal occurs in the member in a quarry in the SE sec. 14, T. 10 S., R. 15 E.

Fossils in the Soldier Creek are confined primarily to the limestone and claystone beds in the basal and uppermost parts. Pelecypods and gastropods, some of which may be bellerophontacean forms (E. L. Yochelson, written commun., 1960), are very abundant in some beds; Osagia, crinoid stems, bryozoans, brachiopods, and carbonized plant material are also present.

Wakarusa Limestone Member--The name Wakarusa was originally given by Beede (1898, p. 30) to a limestone bed about 40 feet above the top of his Stanton (Burlingame Limestone Member) Limestone. Subsequent fieldwork showed, however, that Beede's Wakarusa was actually the present Reading Limestone Member of the Emporia Limestone (Moore, 1936a, p. 219), and the Wakarusa, as used by Condra (1927, p. 77) and other authors, is equivalent to the upper part of Beede's Stanton Limestone. Because Condra's use of the name Wakarusa had been applied extensively in publications, Moore (1936a, p. 218-220) believed that it would be desirable for usage to take precedence over priority of definition in application of the name, In present usage, therefore, the Wakarusa Limestone Member of the Bern Limestone is the first thick limestone above the top of the Burlingame Limestone Member and is underlain by the Soldier Crook Shale Member.

The Wakarusa is present along the Wakarusa River just south of Auburn (west of the mapped area) at the type locality of the Wakarusa Limestone as defined by Beede; however, its exposures are better along the North Branch Wakarusa River about 1 mile west of Auburn. The Wakarusa forms a narrow inconspicuous bench on the hillside above the ledge or escarpment of the Burlingame Limestone Member. In good exposures the Wakarusa crops out as a dual ledge, in which the upper bed is the thicker and more prominent.

The Wakarusa is 3-4.3 feet thick and generally consists of two limestone beds separated by claystone. The limestone is typically light olive gray, although it is medium gray to brownish gray locally, It is very finely crystalline, very thin to medium bedded, hard, and compact and generally weathers various shades of olive gray, yellowish brown, or yellowish orange. The lower limestone is typically a single bed 0.4-2 feet thick; generally it is less than 1 foot thick. In some localities a thin claystone parting occurs in the upper part of the lower limestone. The upper limestone, about 2 foot thick, is vertically jointed, and weathers to large angular blocks, Locally the uppermost part of the upper limestone weathers to platy fragments.

Claystone of the Wakarusa is light olive gray to olive gray, silty, laminated to platy, and calcareous and weathers light olive gray and, locally, yellowish brown or yellowish orange. Thin lenses of argillaceous fossiliferous limestone occur at many localities. The claystone is 0.3-1.3 feet thick and has upper and lower contacts that are generally uneven and gradational. In a few places along the Kansas Turnpike, yellowish-gray sandstone is present between the limestone beds of the Wakarusa.

Fossils are abundant and varied. The lower limestone is characterized by small fusulinids, crinoid stems, and Osagia and other incrusting algae. The upper limestone contains two distinct fossil zones: the lower 1 foot (one zone) is characterized by an abundance of crinoid remains (mainly stems) and the absence of fusulinids; the upper part (the second zone) is characterized by an abundance of large fusulinids. Brachiopods are numerous in all beds and Cryptozoon-like algae are conspicuous in relief on the weathered upper limestone. Small fossil fragments, particularly in the upper limestone, are light reddish brown, probably from an algal coating. The Wakarusa Limestone Member contains the following fossils, reported on by E. L. Yochelson (written commun., 1960):

USGS fossil locality 19457-PC (fl2975). In stratigraphic section 10.

Fusulinids, undet. (abundant)
Crinoid stems
Fenestrate bryozoans, indet.
Derbyia ct. D. crassa (Meek and Hayden)
Chonetes granulifer Owen
Reticulatia huecoensis (R. E. King)
Marginifera wabashensis (Norwood and Pratten)
Composita subtilita (Hall)
"Spiriferina" kentuckensis (Shumard)
Hustedia mormoni (Marcou)

Additional forms (not from locality 19457-PC) include:

Lamellar algae (of Ivanovia type)
Algae (Cryptozoon? type)
Rhomboporoid bryozoan
Composita cf. C. subtilita (Hall)
Hustedia sp. indet.
Wellerella? sp. indet.
Pectenoid? pelecypod, indet.
Cephalopod?, indet.

In addition to collection f12975 (100, 19457-PC) just mentioned, fusulinids from the Wakarusa are retained in USGS foraminiferal collections f12973, from a quarry in the center of the NW sec. 26, T. 10 S., R. 15 E., Shawnee County; f12977, from a roadcut on the west line of the NW SW sec. 19, T. 9 S., R.17 E., Jefferson County (east of the mapped area) ; and f12990, from stratigraphic section 12.

Auburn Shale (strat. section 12)--The Auburn Shale was named by Beede (1898, p. 30) for the shale overlying his Wakarusa Limestone and underlying the Elmont Limestone, but, because Beede's Wakarusa is equivalent to the present Reading Limestone Member of the Emporia Limestone, the term Auburn was originally applied to the present Harveyville Shale Member of the Emporia. Condra (1927, p. 78) applied the name Auburn to the shale underlying the Reading and overlying the Wakarusa of present usage, and this definition has been generally accepted. Although Beede did not designate a type locality, undoubtedly it is near Auburn, Kans. There are good exposures of the Auburn Shale along the Kansas Turnpike in the NE SW sec. 35, T. 13 S., R. 14 E., southwest of Auburn.

Typically, the Auburn Shale forms a fairly steep vegetation-covered slope, in which exposures are confined to stream gullies and roadcuts. Along the west side of the area, south of Topeka, a limestone bed in the upper part forms a pronounced hillside bench. The Auburn is about 25-30 foot thick north of the Kansas River and about 45 feet thick south of the river. The Auburn rests conformably on the Wakarusa Limestone Member of the Bern Limestone, and its basal contact is sharp and even.

The Auburn is primarily claystone but includes some thin beds of siltstone and limestone. The claystone is generally light olive gray to olive gray, silty, finely laminated to platy, and partly calcareous. The blocky fragments on the weathered outcrop are light olive gray to light yellowish gray. A dark-gray to grayish-black finely laminated to platy hard siltstone that is generally 0.7-0.9 foot thick occurs 11-13 foot below the top of the formation. This siltstone weathers to fissile plates and forms a hard bed that, together with an underlying light-colored claystone, is very conspicuous, thin beds and lenses of light-olive-gray to light-yellowish-gray very finely crystalline argillruceous very fossiliferous limestone are present in the upper 10 foot of the Auburn Shale. The beds are generally less than 0.2 foot thick, but near the edge of the area, northwest of Elmont, they are as much as 1.3 foot thick.

Fossils in the Auburn Shale are confined. mainly to the dark siltstone and overlying limestone and claystone in the upper part. The silltstone contains very abundant ostracodes and many, small brachiopods, probably Lingula. Crinoid stems, bryozoans, Chonetes, Neospirifer, and other brachiopods and myalinid pelecypods are abundant in the overlying beds. E. L. Yochelson (written commun., 1960) reported on the following forms from these beds:

USGS fossil locality 19456-PC. In stratigraphic section 12.

Crinoid stems
Linoproductus prattenianus (Norwood and Pratten)
Cancrinella cf. C. boonensis (Swallow)

Emporia Limestone (strat. sections 12, 13)--The Emporia Limestone was named by Kirk (1896, p. 80) from exposures at Emporia, Kans., but considerable ambiguity existed as to just what limestone beds Kirk intended to include in the Emporia. So, Condra (1927, p. 78) redefined the Emporia as the limestone unit underlain by the Auburn Shale and overlain by the Willard Shale. The Emporia Limestone consists, in ascending order, of the Reading Limestone, Harveyville Shale, and Elmont Limestone Members. The type section of the Emporia was not clearly defined by Kirk, but the formation is well exposed along U.S. Highway 50 a few miles east of Emporia (Mudge and Burton, 1959, p. 17).

The Emporia forms a low escarpment or hillside bench, but exposures are confined mainly to streambanks and roadcuts. Thickness of the formation is uniform and ranges from, about 16 to 20 foot. The contact between the, Emporia and the underlying Auburn Shale is conformable and even. The contacts between the members of the Emporia are also conformable.

Reading Limestone Member--The Reading was originally designated by Smith (1903, p. 100) as the Emporia Blue Limestone, but he later renamed it the Reading Blue Limestone (1905, p. 150), Moore (1936a, p. 224) deleted the term "blue" from the name and regarded the Reading as the lower formation of the Emporia Limestone. In 1956 he and Mudge (p. 2276) reduced the Reading in rank to that of lower member of the Emporia. The type locality is near Reading, Lyon County, Kans., according to Moore (1936a, P. 224), who listed excellent exposures in a roadcut near the NW cor. sec. 33, T. 17 S., R. 13 E., about 1 mile northwest of the town.

The Reading Limestone Member is 1.8-2.6 feet thick and is typically medium gray, very finely crystalline, thin to thick bedded, hard, and compact and, in part, has subconhoidal fracture. The member consists of two or three beds, the upper of which is a 0.3-foot-thick bed of slightly argillaceous limestone that weathers moderate to dark yellowish brown and forms a step that is set back slightly from the outcrop face, Characteristically the weathered limestone blocks of the Reading are mottled light olive gray and moderate yellowish brown, and the zone of weathering extends deep into the rock. Dark limonite stains are generally conspicuous on the upper surface. Locally, small inclusions of light-red barite are in the Reading. In the SW NE sec. 10, T. 10 S., R. 15 E., an intraformational breccia about 0.4 foot thick occurs approximately 1.8 feet above the base.

The Reading is characterized by an abundance of crinoid stems that weather white and stand out in relief. Brachiopods are also abundant, and large fusulinids are common but are generally not conspicuous. Fossils from the Reading Limestone Member, reported on by E. L. Yochelson (written commun., 1960), include:

Fusulinid, indet. (probably USGS colln. f12956A, from strat. section 12)
Lophophyllidid coral
Crinoid stem
Rhomboporoid bryozoan
Echinoconchus moorei Dunbar and Condra

Harveyville Shale Member--The first to formally describe the Harveyville was Moore (1936a, p. 226), although Condra (1935, p. 10) was the first to publish the name, Condra classified the Harveyville as the middle member of his Preston (now known to be the Emporia) Limestone, but Moore gave the shale formational rank. Moore and Mudge (1956, p. 2276) reduced the Harveyville to member rank in the Emporia Limestone. The type locality, according to Moore (1936a, p. 226), is near Harveyville, southeastern Wabaunsee County, Kans., Mudge and Burton (1959, p. 18) stated that the member is not exposed in that part of the county, but according to Moore (1936a, p. 226), it is exposed in sec. 25, T. 15 S., R. 13 E., in Osage County.

The Harveyville Shale Member crops out in the northwestern part of the area, where it is 10.5-14.4 feet thick. South of the Kansas River only the basal part of the Harveyville is present.

The member is composed of light-olive-gray to olive-gray silty claystone that weathers to light-olive-gray blocky fragments. At most localities the claystone contains abundant very small nodules of very light gray, very light olive gray, or light-olive-brown limestone. Ferruginous siltstone is present locally in very thin lenses and pellets that weather moderate yellowish brown. Except for a few shell fragments in the upper part, the Harveyville is unfossiliferous.

Elmont Limestone Member--Beede (1898, p. 30) named the Elmont, and Condra (1935, p. 10) included it as the upper member of his Preston (Emporia) Limestone, Moore (1936a, p. 226-227) classified the Elmont as a formation, but later he and Mudge (1956, p. 2276) redefined the Elmont as a member of the Emporia Limestone. The type locality is near Elmont, in northern Shawnee County, Kans.

The Elmont, 3.3-4.6 feet thick, is predominantly limestone but in places contains thin claystone partings. The basal 0.5-1 foot consists of pale-olive, light-brownish-gray, or light-yellowish-brown very finely crystalline very thin to thin-bedded algal-molluscan limestone. A few angular to round dark-gray limestone pellets are present, particularly in the upper part of this basal limestone. Overlying the algal-molluscan limestone at many localities is a medial bed of argillaceous unfossiliferous limestone about 2 feet thick that weathers to light-olive-gray to light-yellowish-gray blocks containing many inclusions of light-yellowish-brown and light-yellow calcite. In places a thin light-olive-gray to light-greenish-gray silty claystone is also present in this medial part. Near the north edge of the area, the medial part contains a medium-gray to light-brownish-gray hard dense partly conglomeratic limestone 1.2-1.3 feet thick which overlies the argillaceous limestone. The conglomeratic limestone consists of very small angular to subrounded pebbles of light-olive-gray to dark-gray dense limestone. The upper unit of the member is a single vertically jointed light-olive-gray very finely crystalline hard compact fossiliferous limestone bed about 1 foot thick. The upper 0.1 foot of this bed is slightly argillaceous and weathers to platy fragments.

Distinct faunal assemblages in the various parts of the Elmont aid in identifying this member. Algae, pelecypods, and some bryozoans and foraminifers are present in the basal bed, ostracodes and pelecypods occur near the middle, and small fusulinids and brachiopods are characteristic of the upper bed. The fossil fragements in the upper limestone are commonly reddish brown--a characteristic which aids in identifying the bed. The few fossils collected by the authors from the Elmont Limestone Member were identified by E. L. Yochelson (written commun., 1960) as follows:

Algae (lamellar)
Algae? (pelletal or "oatmeal")
Myalina (Orthomyalina) sp. indet.
Septimyalina? sp. indet.
Shell fragments, indet.
Ostracodes, undet.

Willard Shale (strat. sections 12, 13)--The name Willard Shale was applied by Beede (1898, p. 31) to the shale that overlies the Elmont Limestone Member of the Emporia Limestone and underlies the Tarkio Limestone Member of the Zeandale Limestone. The type locality is near Willard, on the Shawnee County-Wabaunsee County line, and exposures are good in cutbanks along Post Creek south of the town.

The Willard Shale forms a relatively steep slope between the Emporia and Zeandale Limestones, but is well exposed only along streams and in roadcuts. The Willard is 40-47 feet thick. Claystone forms the major part of the formation, but thick sandstones are also present (principally in the upper part), and in places siltstone is interbedded with the claystone. The claystone is generally light olive gray, silty, and platy and weathers light olive gray to light olive brown. The siltstone is sandy, and micaceous and similar in color to the claystone. Weathered outcrops are covered with pencil-shaped siltstone fragments and are broken by narrow nearly vertical fractures filled with siltstone. Sandstone of the Willard is light yellowish gray to light oIive gray, very fine grained, partly silty, and micaceous, Locally it contains concentric-weathering ferruginous concretions as much as 0.6 foot in diameter. Bedding planes are markedly stained by limonite. The weathered outcrop is light olive gray mottled with pale to moderate yellowish brown.

The Willard Shale rests conformably on the Emporia Limestone, and the contact is sharp and even. Except for a few crinoid stems locally present in the lower few feet, the Willard is unfossiliferous.

Zeandale Limestone (strat. sections 13, 14)--The Zeandale Limestone was named by Moore and Mudge (1956, p. 2276) for the town of Zeandale, in southeastern Riley County, Kans. The type section is in the SE NE NE sec. 28, T. 10 S., R. 9 E., along a north-south farm-access road a quarter of a mile south of Zeandale (Mudge and Burton, 1959, p. 21). The Zeandale Limestone is divided into three members, which are, in ascending order, the Tarkio Limestone, Wamego Shale, and Maple Hill Limestone Members.

The Zeandale Limestone, 15-18 feet thick, forms a fairly low but distinct bench in much of its outcrop area in the northwestern part of the mapped area. Exposures of the lower part of the formation are generally good, but the upper part crops out only in roadcuts and along steep gullies.

The Zeandale Limestone rests conformably on the Willard Shale, and the basal contact is sharp and slightly uneven. The contacts between the individual members of the Zeandale are also conformable.

Tarkio Limestone Member--The Tarkio was originally termed the "Chocolate limestone" (Swallow, 1867, p. 67). Calvin (1901, p. 420, 430) applied the name Tarkio to a limestone exposed in Tarkio Creek, north of Coin, Page County, Iowa. Condra and Bengston (1915, p. 8) assigned the name Tarkio to the upper limestone of their Nemaha Formation and listed the next lower limestone of that formation as the Preston (Emporia). Later Condra (1927, p. 63-64, 71) stated that the Tarkio was the "Chocolate limestone" in Kansas and that it overlies the Willard Shale, but in 1934 Condra (Moore, 193681, p. 229), after studying the type locality of Calvin's Tarkio, concluded that the Tarkio was correlative to the beds in Kansas called the Emporia Limestone, Because the type locality on Tarkio Creek in Page County, Iowa, does not contain beds now described as the Tarkio, Moore (193681, p. 230) designated as the type section the exposures of the Tarkio noted by Swallow (11867, p. 67) on Mill Creek, southwest of Maple Hill, Wabaunsee County, Kans.

The prominent ledge formed by the Tarkio is broken by widely spaced vertical joints, and commonly, weathering produces many large holes in the limestone blocks. The Tarkio is 1.8 to about 4.5 feet thick and commonly comprises two limestone units separated at many places by a claystone about 0.3 foot thick. The limestone is light olive gray, very finely crystalline, slightly argillaceous, thin to medium bedded, hard, and compact. It weathers light olive gray to yellowish brown and, where deeply weathered, forms wedge-shaped slabs. At many localities the upper limestone unit has a brecciated appearance because of fine joints and fractures filled with light-colored calcite, and at others it is compact and sparsely fossiliferous; it everywhere shows a wide range in thickness. Characteristically, abundant large fusulinids weather in relief on the lower limestone. The claystone is light olive gray, slightly silty, and platy and contains abundant very small limestone inclusions.

The Tarkio is characterized by the presence of the large robust fusulinid Triticites ventricosus (Moore, 1936a, p. 230) in the lower limestone. The upper limestone also contains fusulinids, but generally they are less abundant and locally are restricted to the lower part of the upper limestone. Fusulinids from the Tarkio are included in USGS foraminiferal collections f12991,from stratigraphic section 12, and f12968, from stratigraphic section 14. Brachiopods and crinoid stems are common to abundant, and some horn corals, bryozoans, and echinoids are also present. Cryptozoon-like algae occur in the upper limestone in a few places.

Wamego Shale Member--The Wamego was named by Condra and Reed (1943, p. 42) to replace the name Pierson Point that had previously been assigned by Condra (1927, p. 80) to the strata between the top of the Tarkio Limestone Member and the base of the Maple Hill Limestone Member. The name Pierson Point was discarded because at its type locality, it included beds between the Dover and Tarkio, not just those between the Maple Hill and the Tarkio. The Pierson Point Shale was classified as a formation in Kansas (Moore, 1936a, p. 232) and was retained by the State Geological Survey of Kansas until Moore and Mudge (1956, p. 2276) substituted the name Wamego for the middle member of the Zeandale Limestone. The type locality of the Wamego is in the bluffs north of U,S. Highway 40 about 4 miles west of Wamego, Pottawatomie County, Kans. (Condra and Reed, 1943, p. 42).

The Wamego, about 12 feet thick, is composed primarily of claystone containing a few interbeds of limestone and sandstone in the lower half, the claystone is light olive gray, silty, and platy and weathers light olive gray to light olive brown. Locally very thin to thin beds of very fine grained silty ferruginous sandstone thwt weathers light olive brown are interbedded with the claystone. Along the west edge of the area, a bed as much as 3.5 feet thick of sandy thin-bedded limestone that weathers moderate yellowish brown occurs 3-5 feet above the base of the Wamego. In places this limestone contains many small argilaceous limestone pellets. The upper 0.2 foot of the bed is a mass of shell fragments, but the rest contains only scattered fossils.

Brachiopods are the most common fossils in the Wamego Shale Member; they occur in the limestone beds together with crinoid stems, bryozoans, and pelecypods.

Maple Hill Limestone Member--The Maple Hill was named by Condra (1927, p. 80) for exposures along Maple Creek (now known as Mill Creek), southwest of Maple Hill, Kans. Condra classified the unit as a bed in his McKissick Grove Shale Member of the Wabaunsee Formation. This limestone had previously been included as part of the Emporia Limestone (Adams, Girty, and White, 1903, p. 52) and also as part of the Admire Group (Haworth and Bennett, 1908b, p. 114). Moore (1936a, p. 233) defined the Maple Hill as a formation, but later he and Mudge (1956, p. 2276) reclassified it as the upper member of the Zeandale limestone. The type locality is along Mill Creek south of Maple Hill, in the NW SE sec. 26, T. 11 S., R. 12 E., Wabaunsee County (Mudge and Burton, 1959, p. 25).

The Maple Hill is a single stratum 1.3-24 foot thick of light-olive gray to medium-gray very finely crystalline thin-bedded hard limestone. It weathers light olive gray mottled with moderate yellowish brown and dark brown, especially on the upper surface. Commonly the upper surface is limonite stained and has a conspicuous red color. Between widely spaced vertical joints the bed weathers to large rectangular blocks that break into thin slabs.

The fauna of the Maple Hill is characterized by abundant small slender fusulinids, some of which are in USGS foraminiferal collection f12971, from stratigraphic section 13. Brachiopods and crinoid stems are also abundant, and bryozoans, horn corals, and echinoid plates are common. Cryptozoon-like algae are common in the upper part.

Pillsbury Shale (strat. section 14)--The Pillsbury Shale was included as an unnamed shale in both the Emporia Limestone (Adams and others, 1903, p. 52) and the Admire Group (Haworth and Bennett, 1908b, p. 114), In 1927, Condra (p. 80) named this shale the Table Creek of the McKissick Grove Shale Member of the Wabaunsee Formation. In 1943 he and Reed. (p. 42) discarded the name Table Creek, because the type locality included three other formations, and introduced the name Langdon Shale for the beds underlying the Dover and overlying the Maple Hill. At its type section, however, the Langdon is correlative to the Wamego Shale Member of the Zeandale Limestone (Moore and Mudge, 1956, p. 2275); consequently, the name Langdon was abandoned and the name Pillsbury was assigned by those authors to the beds between the Dover and Maple Hill Limestone Members. The formation was named from Pillsbury Crossing, a ford across Deep Creek in the NE NW sec. 5, T. 11 S., R. 9 E., Riley County, Kans. (Moore and Mudge, 1956, p. 2275). The type exposure is in a roadcut in the SE NE NE sec. 28, T. 10 S., R. 9 E., Riley County.

The Pillsbury, about 40 feet thick, underlies stream divides in the northwestern part of the area, but a few roadcuts offer the only good exposures. The formation is mainly light-olive-gray silty platy claystone; in the upper third the claystone is interbedded with clayey siltstone that weathers light olive gray to moderate yellowish brown. The siltstone is limonite stained on the bedding planes. The uppermost part of the Pillsbury is very calcareous and contains thin lenses of light-olive-gray fossiliferous limestone. Where the contact was observed the Pillsbury rests conformably on the Zeandale Limestone. Scattered fusulinids, crinoid columnals, and small brachiopods occur in the claystone immediately beneath the Dover Limestone Member of the Stotler Limestone.

Stotler Limestone (strat. section 14)--The Stotler Limestone was named by Moore and Mudge (1956, p. 2275) for the old Stotler Post Office, which was in the SW sec. 10, T. 16 S, R. 13 E., Lyon County, Kans. The type section is in the spillway and along the south side of a pond in the SE sec. 13, T. 16 S.,, R. 12 E., which is north of U.S. Highway 56 and about 2 miles west of Miller (Moore and Mudge, 1956, p. 2275). The Stotler contains three members, which are, in ascending order, the Dover Limestone, Dry Shale, and Grandhaven Limestone Members.

Rocks in the Dover Limestone Member and in the lower part of the Dry Shale Member are the uppermost beds of Pennsylvanian age exposed in the mapped area. The rest of the Stotler Limestone land part of the overlying Root Shale are probably present beneath the glacial drift near Hoyt. Only the lower 4 feet of a total thickness of about 7 feet of Stotler is exposed. The Stotler Limestone rests conformably on the Pillsbury Shale, and the contact is gradational through about 0.5 foot of very calcareous slightly resistant claystone.

Dover Limestone Member--The Dover was named by Beede (1898, p. 31) from exposures near Dover, Shawnee County, Kans. This limestone was included in the Emporia Limestone by Adams, Girty and White (1903, p. 52), in the Admire Shale (now the Admire Group) by Haworth and Bennett (1908b, p. 114), and in the McKissick Grove Shale Member of the Wabaunsee Formation by Condra (1927, p. 80). Moore (1936a, p. 235) classified the Dover as a formation that underlies Ibhe Dry Shale and overlies the Table Creek (Pillsbury) Shale. Moore and Mudge (1956, p. 2275) reduced the Dover to the rank of member of the Stotler Limestone.

The Dover Limestone Member is not present at Dover but is well exposed about 1.5 miles west of Dover along State Route 10 in the NW SW sec. 34, T. 12 S., R. 13 E., Wabaunsee County, and about 1.5 miles east of Dover in a roadcut in the SW NW sec. 31, T. 12 S., R. 14 E., Shawnee County.

The Dover crops out at only two localities; it occurs as a small outlier on a ridge in the SE sec. 22 and SW sec. 23, T. 9 S., R. 15 E., and it is partly exposed in a roadcut on the west line of the SW sec. 24, T. 9 S., R. 15 E. Elsewhere, as near Hoyt, the member is concealed by glacial drift.

The Dover is 2-2.4 feet thick and is composed of light-olive-gray very finely crystalline argillaceous hard compact limestone that weathers light olive gray and has a brown tint. Thin partings of calcareous claystone are interbedded ih the lower 0.6 foot of the member. The Dover forms a vertically jointed ledge in which the limestone weathers to small irregular rubbly blocks and plates.

Very abundant large fusulinids and abundant Crytozoon-like algae and brachiopods are characteristic of the Dover Limestone Member; hence, they are a very useful aid in identifying it. The fusulinids are particularly abundant in the lower part, where they weather in relief on the rock surface. The algae are concentrated in the upper part and weather out as biscuit-shaped masses. Horn corals are also common. The Dover Limestone Member contains the following fossils, which were reported on by E. L. Yochelson (written commun., 1960):

Algae (Cryptozoon)
Small foraminifers, undet. (USGS colln. fl2967, from strat. section 14)
Fusulinids, undet. (abundant) (USGS colln. fl2967, from strat. section 14)
Crinoid stems
Echinoid spines
Marginifera ct. M. histricula Dunbar and Condra
Hustedia sp. indet.

Dry Shale Member--The Dry was defined as a formation by Moore (1936a, p. 236), although it had first been recognized and named in a stratigraphic section by Moore, Elias, and Newell (1934). In 1956 Moore and Mudge (p. 2275) classified the Dry as the middle member of the Stotler Limestone. The type locality is on Dry Creek southwest of Emporia, in sec. 5, T. 20 S., R. 11 E., Lyon County, Kans. (Moore, 1936a, p. 236).

About 2 feet of an estimated. thickness of 4 feet of the Dry Shale Member is exposed in a roadcut in the SE SE sec. 22, T. 9 S., R. 15 E. In this small exposure the Dry consists of light-olive-gray platy calcareous claystone that weathers light olive gray mottled with light olive brown. Unfossiliferous limestone nodules as much 1 foot long and 0.5 foot thick that weather light olive brown are abundant. The member is unfossiliferous at this locality.


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Kansas Geological Survey, Geology
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