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Red Eagle Formation

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Studies of insoluble residues obtained by acid treatment of rocks belonging to the Red Eagle cyclothem showed that clays are the most abundant minerals. Clay is the bulk of the shale in the Johnson and Roca, regardless of color, and is an important constituent of the Red Eagle Limestone. Differential thermal analyses and x-ray diffraction patterns from selected samples taken at the Bennet, Manhattan, and Pawnee sections showed that illite is the most common and abundant clay mineral in the northern part of the outcrop belt. Chlorite is commonly present in small amounts. These green minerals account for the greenish tint in most of the gray Johnson and Roca Shales. Traces of calcium montmorillonite and some unknown mixed-layer minerals are randomly rare in the Johnson and Roca Shales.

It is significant that, as in the shale, the major constituent of the small amounts of clay in limestone of the Red Eagle is illite; there are traces of chlorite.

The mineral calcite is next in abundance in the Red Eagle cyclothem. Finely divided calcite is present in almost all shale and in all limestone matrices. Shell remains, some originally aragonite but now changed to calcite, make up a large part of the calcium carbonate in the Red Eagle Limestone. Algal calcium carbonate is also significant. Traces of dolomite are present in some shale beds of the Red Eagle cyclothem.

Insoluble residues also showed that traces of clear subangular to subrounded quartz slit are widespread in all units of the Red Eagle cyclothem. The minor amounts of quartz silt in the Red Eagle Limestone seem mostly to have been built into the shells of arenaceous forminifers. In the Johnson and Roca Shales the quartz silt is sparsely dispersed. Traces of muscovite rarely accompany the quartz in some residues.

GIauconite is extremely rare in the Bennett Shale. At the Grand Summit section gIauconite fills tiny gastropod shells in the lower part of the Bennett.

Variable small amounts of limonite occur in limestone of the Red Eagle cyclothem in some places. The osagite facies of the Howe Limestone is characteristically limonitic where weathered. Limonitized fossils are rarely evident in limestone of the Bennett Member. Hematitic pyritohedral pseudomorphs are present in the limestone near the type locality of the Red Eagle Limestone in Oklahoma.

Siliceous materials such as beekite are rare in the Red Eagle Limestone of southern Kansas.

Rare manganese dioxide dendrites are present along shaly laminae in some of the weathered calcareous shale in the Red Eagle cyclothem.



Fragmentary carbonized plant remains and impressions are commonly present in the uppermost gray shale of the Johnson Formation. Much of this material is vitreous and is coalified to the extent that details of original organic structure are rarely visible. Only one fragment could be identified definitely as remains of a gymnosperm. Traces of fragmentary carbonized materials are present but rare in some gray shale in the lower part of the Bennett Member and in the uppermost shale of the Roca Formation.

Evidence of the activities of algae is present in the Red Eagle Formation. The secondary laminar calcium carbonate deposits which coat small shell detritus, especially in the Howe Limestone and to a much lesser degree in the GIenrock Member, are attributed to precipitation caused by algae and have been given the "form" generic name Osagia (Johnson 1946, p. 1104). The Howe Member so abounds with these pellets of Osagia that it and similar rocks in other parts of the column have been called osagite. Limestone of the Bennett Member contains traces of so-called linear algae at some localities (Pl. 5). These are really ribbon-like and thin, crustose, often sparry, calcium carbonate structures, some of which are related to Anchicodium. Harbaugh (1959) noted similar algal materials in Pennsylvanian rocks. Also, the masses of apparently structureless calcium carbonate which constitute much of the matrix of Bennett limestone are believed to be largely algal in origin (consolidated algal "dust" particles)

Oogonia of charophytes ascribed to the genus Trochiliscus have been found in upper (and lower) parts of the Johnson Shale at two localities. [Note: Some of the charophytes might be assignable to the new genus Catillochara, described by R.E. Peck and J.A. Eyer (1963).] Lane (1958, p. 129) was the first to note "charophytes" in uppermost shale of the Roca in southern Kansas.

Several genera of spores are present in the lower black shale of the Bennett Member. These include Pityosporites sp., Lueckisporites sp., Florinites sp., Punctatisporites sp., Nuskoisporites sp., Entylissa sp., and Cycadopites? sp. This list records results from analyses of the few samples chosen to give a general indication of the spore content in the Red Eagle cyclothem. Doubtless the list is incomplete. It is interesting to note that the genera seem to be similar to younger Permian assemblages from other parts of the world. Could this indicate that in Wolfcampian time middle North America was the cradle of development of a floral assemblage which did not flourish on other continents until later in the Permian?

Few works on fossil spores and pollen from the Pennsylvanian and Permian rocks of Kansas have been published. It may be expected that much will be added to understanding of cyclothems and paleoclimatology when more spore and pollen data are assembled. The new information should be used to affirm or revise the presently recognized (Moore and Moss, 1934) position of the Pennsylvanian-Permian boundary in Kansas and adjoining states.


The Johnson and Roca Shales are mostly either barren of fossils or only very sparsely fossiliferous. On the other hand, the Red Eagle Limestone is abundantly fossiliferous. Gastropods and ostracodes are the only major groups of invertebrates that occur in all stratigraphic units of the Red Eagle cyclothem. The invertebrates represented are mostly confined to the Red Eagle Limestone formation. Table 3 lists all animal fossils found in the Red Eagle cyclothem.

Table 3.--Animal remains recognizable in the Red Eagle cyclothem.

Larger forms (fusulinids)
Smaller forms (mostly arenaceous)
Ammobaculites Glomospira
Ammodiscella Glyphostomella
Ammodiscina Hyperammina
Ammodiscus Nodosinella
Ammovertella Nummulostegina
Bigenerina Tetrataxis
Cornuspira Tolypammina
Globivalvulina Trochammina
Unidentified horn corals (lophophyllids)
Acanthocladia Polypora
Bactropora Rhabdomeson
Chainodictyon Rhombopora
Fenestella Saffordotaxis
Fenestrellina Septopora
Megacanthopora Syringoclemis
Minilya Thamniscus
Ambocoelia Linoproductus
Chonetes Marginifera
Composita Neospirifer
Crurithuris Rhipidomella
Derbyia Schuchertella?
Dictyoclostus Wellerella
Echinoconchus Unidentified fragments
and spines
Small unornamented forms
Unidentified coiled and straight nautiloids
Columnal discs
Interambulacral plates
Unidentified pygidial or thoracic remains
Amphissites Jonesina
Aparchites Kirkbya
Bairdia Kirkbyella
Bythocypris Knightina
Cavellina Macrocypris
Cypridina Parapachites
Cytherella Roundyella
Discoidella Ulrichia
Geffenina Youngiella
Netlike sclerites (Eocaudina?)
Small, wheel-shaped sclerites (Paleochiridota?)
Cavusgnathus Polygnathodella
Hindeodella Prioniodina
Lonchodus Streptognathodus
Moreyella Synprioniodinia
Tooth fragments
Cooleyella Multidentodus
Cooperella Palaeoniscus
Distacodus Scolopodus
Worm burrows

Stratigraphic Paleontology

Figure 4 shows the stratigraphic position of all fossils recognized in the Red Eagle cyclothem as a result of this study. To some extent recognition of these fossils and estimations of relative abundance depend on the efficiency and refinement of extraction methods. Most genera named were collected from shale of the Bennett Shale Member of the Red Eagle Limestone. A. G. Fischer recognized ostracodes, gastropods, bryozoans, spicules, and echinoid fragments in the algal colonies at the top of the Howe Member at the Allen No. 2 locality (H. G. O'Connor, personal communication).

The fusulinid Triticites is the most abundant fossil in the entire Red Eagle cyclothem (Fig. 4). It is mainly confined to the GIenrock Limestone, wherein at many places its large numbers constitute a major part of the rock. A few Triticites are present in the lowermost shale and the limestone facies of the Bennett Member, and in the uppermost beds of the Johnson Shale only at the Highway 38 section. O'Connor and Jewett (1952, p. 335) observed a fusulinid in the Howe Limestone near the Allen No. 2 section.

With only five exceptions, identified foraminifer genera are confined to the Red Eagle Limestone. Ammodiscus, Ammovertella, and Tolypammina are arenaceous foraminifers found in both the Johnson and Red Eagle Formations. There are no publications on Permian arenaceous foraminifers, but Ireland (1956) has found them in beds younger than Red Eagle and has stated that they are indistinguishable from Late Pennsylvanian forms he has described. Tetrataxis ranges from uppermost beds of the Johnson Shale, through the Red Eagle Limestone, to the lowermost Roca Shale. Cornuspira is very rare in the upper part of the Johnson Shale.

Bryozoans (mostly cryptostomes) are mostly confined to the Bennett and Glenrock Members of the Red Eagle Formation. Penniretepora, characteristic of the Bennett Member, is also found at the top of the Johnson Shale and rarely in the upper part of the Roca Shale. All bryozoan genera named were washed from shale. The fenestellate bryozoans in the Glenrock Limestone are not readily identifiable because they are difficult to extract. A few more genera are present in the upper Bennett than in the lower part of the Bennett.

Brachiopod fragments generally occur profusely in the GIenrock and Bennett Members and sparingly in the Howe Member of the Red Eagle Formation.

The inarticulate brachiopod Orbiculoidea is rare to common in the black shale of the lower Bennett, and rare in gray shale and buff limestone higher in the Bennett Member. Here and there Lingula accompanies Orbiculoidea at the base of the Bennett. Orbiculoidea is the stratigraphic indicator of the Bennett Member.

Productid brachiopod fragments and spines are numerous in the Glenrock and Bennett Members. In southern Kansas the upper parts of the Johnson Shale contain Linoproductus and Juresania.

Crurithyris and Chonetes are very rare in uppermost Johnson shale and more numerous in Bennett shale. Crurithyris, the only brachiopod found in all three formations, is very rare in the Roca Shale.

Although ostracodes are present in all units of the Red Eagle cyclothem, they are most numerous in the Red Eagle Limestone. Only the uppermost shale of the Johnson Formation contains many ostracodes, together with the carbonized plant remains. An association of Bairdia, Cavellina, and Bythocypris characterizes the upper part of the Johnson. These genera also appear sporadically in the Red Eagle and Roca Formations. A few Geffenina and Paraparchites are found in the uppermost part of the Johnson Shale but are unknown in the rest of the section. Cypridina, Discoidella, Kirkbya, Kirkbyella, and Knightina have been observed only in the Bennett Member. Ostracodes are rare in the Howe Limestone. Scarce Bairdia, Bythocypris, Cavellina, Cytherella, and Macrocypris are the only ostracodes in the generally unfossiliferous Roca Shale.

All conodonts are confined to the Bennett Member. They prevail in the black shale of the lower part of the Bennett. Streptognathodus is the most common genus. Minute fish teeth? (Idiacanthus, Distacodus) that usually accompany the Bennett conodonts are very scarce in the upper part of the Johnson Shale and in the Roca Shale. The Howe Limestone lacks conodonts and tooth remains.

Tiny gastropods, resembling Anematina, are present in all units of the Red Eagle cyclothem.

Allorisma and Aviculopinna are the only pelecypods found in the Red Eagle cyclothem. Aviculopinna was observed in only two (Nebraska) localities. It occurs, with Allorisma, at the top of the Glenrock Limestone, in Howe Limestone at one locality, and in the Bennett Shale and Howe Limestone at another. One coiled and several straight nautiloid cephalopods were found at the top of the Howe Limestone (Pl. 7 and page 93).

Crinoid columnals are fairly numerous in the Bennett Shale Member of the Red Eagle Limestone, and a few may also be found in the upper part of the Johnson and in the Glenrock and Howe units. Some columnals in shale are flattened by pressure perpendicular to the bedding, presumably from overburden of younger sediments. Echinoid spines are rare to common throughout the Red Eagle Limestone, and they are very rare in the upper beds of the Johnson Shale. Cidaroid interambulacral plates are scarce in the Bennett Member. A single plate was found in the upper part of the Johnson calcareous shale.

Extremely rare pygidial and thoracic remains of trilobites (cf. Ditomopyge) are present only in the Bennett and Glenrock Members of the Red Eagle Limestone.

Holothuroid sclerites may be found only in the upper part of the Johnson Shale and in the Bennett and Howe Members of the Red Eagle Limestone. Achistrum, a hooked form, and Eocaudina?, a netlike sclerite, occur exclusively in the upper part of the Johnson Shale. Wheel-shaped sclerites (Paleochiridota?) are present in the Bennett Shale, the Howe Limestone, and the upper part of the Johnson Shale.

Worm burrows are visible in limestone lenticles of the upper part of the Johnson Shale and in the top of the Glenrock Member of the Red Eagle Limestone.

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Kansas Geological Survey, Geology
Placed on web Jan. 24, 2007; originally published Dec. 1963.
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