Sallyards Limestone Member
The Sallyards Limestone member, which is the lowest subdivision of the Grenola Limestone, was named by Condra and Busby (1933) from exposures near Sallyards, Greenwood County, Kansas (Pl. 1A, C). The description given by Condra and Busby (p. 19) for the type locality is as follows:
"Sallyards limestone, bluish-gray, top rough, weathers light gray to yellow with shale re-entrant, contains Myalina, Aviculopecten, gastropods, Chonetes, bryozoa, and crinoid joints, 2' 6"."
The Sallyards member is underlain by the Roca Shale, which consists of red, green, and gray to light-brown shale. Directly below the Sallyards Limestone the Roca Shale is light brown and clayey to slightly silty. This brown shale is underlain by green and light-maroon clay shale that is unfossiliferous. The upper boundary of the Sallyards member is marked by a limestone stratum,, 4 to 12 inches thick, above which occurs the Legion Shale member, which locally contains strata of thin impure limestone.
Plate 1A--Sallyards Limestone member at locality 3.
Plate 1B--Osagite limestone, upper part of Sallyards member, locality 2. Note incrustations around shell fragments and gastropods. White layers are Ammovertella, gray are ?algae (x10). [Web version enlarged to show more detail.]
Plate 1C--Burr, Salem Point, and Neva members at locality 3.
Physical character--The Sallyards limestone member contains no shale breaks or partings in observed exposures (Fig. 2). The color ranges from light yellow brown to dark blue gray. Thickness of individual beds ranges from 1 inch to 2 feet. Insoluble residues from limestone in the Sallyards consist almost entirely of the tests of Ammovertella, an arenaceous foraminifer (Fig 3). A very few silt-size quartzose particles are present, which may be portions of Ammovertella tests.
Fig. 3--Ammovertella etched from Sallyards Limestone at Locality 2.
Organic character--Two distinct divisions of the Sallyards limestone are distinguished on the basis of contained organic material. The lower division is characterized by a sparse distribution of long (0.1 to 3.0 cm) shell fragments, small gastropods, and ostracodes. These limestones are thin bedded, gray to yellow brown, and argillaceous, and range from 0.8 to 1.7 feet in thickness. The long shell particles may or may not be covered with an incrustation of Osagia-like material and Ammovertella tests. These coatings are found on one or both sides of a fragment and have a maximum thickness of 1.0 mm. Only part of the shell particles in any examined limestone sample shows these incrustations.
The upper limestone division of the Sallyards member contains abundant Osagia, high- and low-spired gastropods 2 to 3 mm high, and ostracodes (Pl. 1B). The Osagia consist of algae and Ammovertella tests surrounding small (1 to 5 mm) shell fragments. No specimens show the supposed algae surrounding recognizable Nubecularia. "Osagite" would surely serve for field description of the upper Sallyards limestone, for the rock is essentially composed of Osagia. Only part of the Osagia individuals shows the "rounded lozenge or bean-shaped colony" described by Johnson (1946). Those individuals that do not exhibit this shape have ?algae enclosing a fragment but no concentration of incrusting material on the ends or top of the shell particle. When a smooth etched surface of this rock is examined, 60 to 90 percent of the surface is seen to be occupied by organic material.
Megascopic fossils in the Sallyards member consist of Composita, Aviculopecten, Pseudomonotis, and myalinids, which usually are found in the lower strata of the member. It seems reasonable that the long shell fragments mentioned above, which show on etched surfaces, are broken individuals of the same genera. These same fossils are probably represented also in the small particles forming nuclei for ?algae and Ammovertella in the upper beds of the Sallyards. The organic character of the member and its relationship to organic remains in the upper part of the Roca Shale is shown in Fig. 4.
Fig. 4--Fossil sequence in upper part of Roca Shale and in Sallyards Limestone.
Lateral changes--The Sallyards Limestone ranges from 1.75 to 4.6 feet in thickness in the area of this study. The increased thickness at the three southern localities is due to thickening of the osagite beds at the top (Table 2).
Table 2--Thickness changes in the Sallyards Limestone, in feet.
Legion Shale Member
The Legion Shale member, overlying the Sallyards Limestone, was named by Condra and Busby (1933) from exposures southeast of the American Legion grounds near Manhattan, Kansas. Their description of the Legion Shale at the type locality is as follows (p. 18):
Legion shale, 4' 6":
- Shale, black, carbonaceous, fissile, 8"-10".
- Mudstone, dark gray, argillaceous, 4".
- Shale, dark gray, calcareous, blocky, 1'.
- Shale, gray, calcareous, blocky, weathers yellow, 2'.
The lower boundary of the Legion Shale is marked by the lowest shale above the Sallyards member. The Sallyards Limestone contained no shale in exposures measured by the writer. The upper boundary of the Legion at localities 2 and 3 is the base of the limestone sequence that makes up the Burr member (Fig. 2). The sequence at these localities is distinctively marked by a massive 31-inch stratum at the top. At locality 1, the boundary is placed at the base of the lowermost thin-bedded limestone in a sequence of thin limestones and shales. Above this sequence is a massive bed that is judged to be the top limestone of the Burr member.
At locality 4 the Legion Shale contains six limestone beds 2 to 18 inches thick. The top of the member is placed below a 1.5-foot bed of limestone showing characteristic Burr lithology, of a type lacking in limestone beds of the upper Legion Shale (Fig. 2).
Physical character--The Legion member is a light-brown to gray calcareous clayey shale. Only very small amounts of silt-size noncarbonate material were noted when samples of the shale were digested in acid. Effervescence was moderate to strong. The shale is soft and regularly thin bedded, and weathers blocky.
Limestone beds in the shale range in thickness from 2 to 8 inches and average 3 inches. Most of these limestones are argillaceous, earthy or nodular, and wavy bedded, and contain few fossils. The insoluble material in them consists mainly of silt-size silica particles and clay.
Organic character--The Legion Shale of the Elk-Cowley County area yielded no megafossils. The microfauna of the shale differs from outcrop to outcrop. At the northernmost locality (1) , only very sparse, poorly preserved shells of Cavellina were found. At locality 2 numerous well-preserved Cavellina were accompanied by abundant small productid spines. The other two localities (3, 4) contained very abundant Cavellina and common Hollinella, Knoxina, Tetrataxis, Glyphostomella, crinoid stems, and productid spines. Cavellina seems to be a persistent and abundant constituent of the Legion microfauna (Table 3).
Table 3--Percentages of identifiable microfossils in the Legion Shale at localities 3 and 4.
Those few limestones that are fossiliferous contain a molluscan fauna consisting mainly of Aviculopecten, Septimyalina, and the brachiopod Juresania. These fossils can be collected best on the upper or lower bedding plane of the limestone bed. The molluscan beds occur at the two southern localities (3, 4). At each of the two northern localities only two thin, unfossiliferous limestone strata are present.
Lateral changes--Three distinct types of lateral change are observed in the Legion Shale. First, the total thickness of limestone beds increases from north to south (Table 4). Second, the microfauna shows an increase both in number of genera and in abundance of individuals to the south. Third, the black carbonaceous shale at the top of the Legion Shale in the type locality to the north is not present in any of the four sections measured for this study.
Table 4--Lateral changes in the limestone-shale components of the Legion Shale, in feet
Burr Limestone Member
The Burr Limestone, named by Condra and Busby (1933), is the third member above the base of the Grenola (Fig. 2, Pl. 2A). The member is named from a town in Otoe County, Nebraska, but no description of the Burr locality is given by Condra and Busby; instead, they refer to the section near Humboldt, Nebraska, for the "type" description of this limestone. At Humboldt, the Burr member consists of two limestones separated by 3.5 feet of brown shale, the upper bed being carbonaceous and less than a foot thick. Black carbonaceous shale in the middle of the Burr member contains abundant plant remains in Nebraska (Condra and Busby, 1933, p. 26). Another feature is a zone of ostracodes in the upper limestone bed. This zone occurs in northern Kansas and Nebraska.
Plate 2A--Burr Limestone member at locality 2.
Plate 2B--Osagite limestone, upper part of Burr member, locality 3, showing layering of fossiliferous osagite and unfossiliferous limestone (X8). [Web version enlarged to show more detail.]
The base of the Burr Limestone in the type area of the Grenola was discussed in conjunction with the Legion Shale. The upper boundary in all sections measured is a massive to medium-bedded limestone of characteristic lithology.
Physical character--The lower limestones of the Burr member, below the typical massive bed at the top, are argillaceous, platy, or nodular, and wavy bedded (Pl. 2A). These lower limestones range 1rom dark gray to light brown. Shale in the Burr member occurs as thin beds in the lower strata, ranging from 1 to 6 inches in thickness. This shale is everywhere calcareous, generally light brown, platy or blocky, and soft, and is composed almost entirely of clay-size particles.
The upper limestone stratum is massive at localities 2 and 3 (Fig. 2), and at other places shows three or four distinct beds ranging from 9 to 19 inches in thickness. This seeming difference in bedding may be due to effects of weathering. The upper, massive bed commonly shows a very faint, wavy, depressed line on the surface, which may be a bedding plane not sufficiently weathered to make an obvious break. The limestone is blue gray to dark gray. It contains very little argillaceous material; the matrix consists of cloudy granular calcitic material, which surrounds abundant organic debris.
Organic character--The lower limestone beds typically contain long (maximum 3.0 cm), thin pectinoid fragments, sparse gastropods, ostracodes, crinoid stems, and echinoid spines. The shell fragments are aligned parallel to the bedding, the convex outer surface upward. This kind of organic debris occurs in thin (2- to 3-inch) beds, either at the base of the Burr member or above a limestone that is similar in organic character to the higher limestones of the member. The only megafossils observed in the lower part of the Burr member were numerous shells of Aviculopecten and sparse specimens of Septimyalina.
Like the upper beds of the Sallyards member, the upper limestones of the Burr may be termed osagite. Small shell fragments, which are surrounded with a layer of ?algae and Ammovertella, are very numerous, and are accompanied by numerous ostracodes and small high-spired gastropods. Organic material was estimated to occupy 80 to 95 percent of the etched surface of samples from the upper limestone stratum. A square inch of the etched surface contains 7 to 40 small gastropods, a maximum of 20 ostracodes, 2 or 3 crinoid columnals, and 75 to 125 shell fragments covered with ?algal coatings.
Shell fragments, ostracodes, and gastropods in this upper limestone average between 1.0 and 2.0 mm in length. The longest observed particle was 10.0 mm. long. The uniform upper size limit of these materials seems to indicate sedimentary sorting. At locality 3 the upper part of the Burr contains parallel laminae of nonorganic, calcitic, and very fossiliferous osagite limestone, 0.5 to 1.0 cm thick, which show on both weathered and fresh surfaces (Pl. 2B). These laminae seem to be the result of current or wave action. No megafossils were found in the upper limestone beds of the Burr member.
Lateral changes--No consistent changes in thickness or lithology were noted in the Burr member. A summary of shale, limestone, and total thicknesses is given in Table 5. No carbonaceous shale or limestone, or plant remains, were found in the Burr member.
Table 5--Lateral changes in the limestone-shale components of the Burr Limestone, in feet
Salem Point Shale Member
The Salem Point Shale, named by Condra and Busby (1933) from exposures near Salem, Richardson County, Nebraska, is next above the Burr Limestone. The description of the Salem Point member at the type locality is, "Salem Point shale, calcareous, 7'-8"."
In the type area of the Grenola Limestone, the Salem Point member is shale, generally unfossiliferous, interbedded with thin, earthy limestone layers. The lower boundary is marked by the upper massive osagite bed of the Burr member. The upper boundary is the base of the first fusulinid limestone, which is the lowest bed of the Neva member.
This lower fusulinid limestone of the Neva was found at all localities except locality 3, where no fusulinids were found and the Salem Point-Neva boundary was placed tentatively on the basis of other aspects of the lithology.
Physical cliaracter--The Salem Point Shale is a calcareous to micaceous, slightly silty shale. Sand-size particles were observed very rarely. Color ranges from dark gray to light yellow brown. The shale layers are 0.2 to 2.0 feet thick and limestone strata 0.2 to 1.0 foot. The limestone beds are nodular or wavy bedded, argillaceous, and shaly. At localities 1 and 2, an argillaceous limestone crops out 2 or 3 feet below the base of the Neva member; it weathers into a limonitic boxwork. This is typical soft, earthy limestone referred to as "punky".
Organic character--Virtually all fossils found in the Salem Point member were in the limestone beds. The only microfossils are sparse Cavellina and Juresania? spines in one bed at locality 4, and charophytes in another bed at locality 2. Both the charophytes and Cavellina occur about 3 feet below the Salem Point-Neva boundary.
Limestone beds contain Aviculopecten, Septimyalina, Pleurophorus, and Juresania. The pelecypods were found at localities 1, 2, and 4; Juresania was found only at locality 4.
Two characteristic arrangements of organic debris were observed in limestone strata of the Salem Point member. Most of the thin limestone beds contain long, curved fragments of disarticulated shells having a maximum length of 4.0 cm and an average length of 2.0 cm,, associated with sparse ostracodes, small gastropods, and small crinoid columnals. Distinct algal coatings were not observed. Two limestone beds, however, showed small Ammovertella tests randomly arranged in the lime-mud matrix, but there was no indication that the tests were fixed to any larger organic particles.
The other arrangement of organic material in the limestone consists of approximately 90 percent organic debris of very small size (0.1 mm or less) showing a distinct lamination. The particles are so small and closely packed that they cannot be assigned to fossil groups. In one limestone, a distinct bedding surface, between fine organic particles below and fine calcareous mudstone above, can be recognized. Several small shell fragments, less than 1.0 cm long, arranged with the convex side up occur in the mudstone. These fragments are all within a millimeter of the bedding surface and surely were placed there by sedimentary transport, then covered by calcium carbonate mud, which grades upward into fine organic debris. If this debris is considered as sedimentary particles, the limestone is actually a coarse siltstone or very fine sandstone.
Lateral changes--The only noticeable organic change in the Salem Point member is the occurrence of Cavellina and Juresania at locality 4 but not at localities farther north. The limestone-shale components do not show any consistent change (Table 6).
Table 6--Lateral changes in the limestone-shale components of the Salem Point Shale, in feet.
|*4.8 feet covered|
Neva Limestone Member
The Neva Limestone was named by Prosser (1895) from exposures near Neva, Chase County, Kansas (Pl. 3A, B), where the Neva member consists of five limestone beds ranging from 1 to 6 feet in thickness. Those are separated by thin (0.2 to 2.0 feet) shales, which are fossiliferous (Condra and Busby, 1933, p. 11). North of Elmdale, Kansas, the lower shales are black and contain Orbiculoidea and Lingula. but these black shales do not occur in the southern Kansas exposures studied.
Plate 3--Neva Limestone member at locality 4.
At localities 1, 2, and 4, the base of the Neva member is defined by the lowest limestone bed in which fusulinids occur. At locality 3 the Neva-Salem Point boundary was placed on the basis of other features of the lithology. The top of the member occurs at a change in slope where the red, green, and gray shale of the Eskridge overlies the upper limestone bed of the Neva member. Upper limestone beds of the Neva Limestone commonly are badly weathered and are difficult to measure exactly.
Physical character--One of the most noticeable gross features of the Neva member in the area studied is lack of persistence of the limestone beds. Many of these beds are dissimilar in lithology from place to place and are difficult to correlate. Some of the limestones weather light gray to light brown and show a rough, pitted surface. Individual beds range from 0.2 to 1.7 feet in thickness. The shales are less than 3 feet thick everywhere. Limestone beds range from very light yellow brown to dark blue gray. The lower one or two limestones usually show argillaceous material on the etched surface, but higher limestone beds of the member often etch to a very smooth surface and seem to have little noncarbonate material. The shales are calcareous and contain minor amounts of silt-size noncarbonate particles.
The upper shales of the Neva member are light brown, but the lower ones are gray or dark gray and may be equivalent to black shale in the lower Neva farther north. The dark-gray shales are fossiliferous, however, and fusulinids are found in the darkest of them.
Chert is present in upper limestone beds of the Neva, individual beds or nodules of chert being as much as 0.5 foot thick (Pl. 4C, 5A). The color ranges from dark gray to whitish gray. Where the chert occurs in more than one stratum at a locality, the lowermost chert is dark gray, and higher chert is light gray to whitish gray. Fossils recognized in the chert are Crurithyris, fusulinids, echinoid spines, and fenestrate bryozoans. At locality 4, one bed of chert contains numerous Crurithyris whose shells are white silica and the interiors are filled with white and light-gray, banded, agate-like silica. The contact between chert and limestone is invariably sharp, but in many places wavy, smooth lobes of chert extend up or down into the limestone as much as 0.5 inch (Pl. 4C, 5A).
Plate 4. A. Grenola Limestone at Grand Summit, Kansas. B. Neva Limestone at locality 2. C. Dark-gray chert nodules in Neva Limestone at locality 4.
Plate 5A--Light-gray chert nodules in Neva Limestone at locality 4.
Plate 5B--Pectinoid limestone, lower part of Sallyards member, locality 2. Organic fragments consist of long thin shell fragments (X5). [Web version enlarged to show more detail.]
Where chert occurs in nodules, the long dimension is parallel to the bedding. Nowhere were bedding planes observed to cross or enter chert beds or nodules, and no laminations or faint bedding planes were seen in limestone near the chert. Therefore, it could not be ascertained whether laminae in the limestone would have followed the wavy chert-limestone contacts or cut across them. Some fossil fragments in the chert are aligned parallel to the chert-limestone contact, probably because the contact is approximately parallel with the limestone bedding.
A few carbonate fossil fragments are embedded in the chert. These could be observed both on etched and weathered surfaces. The limestone bordering the chert beds or nodules contains blebs and stringers of secondary silica, and partly replaced Crurithyris and crinoid stems. Fusulinids are not replaced.
Organic character--The fauna of the Neva differs noticeably from that of the other beds. Instead of an assemblage of flat-shelled pelecypods and small gastropods, the Neva member contains fusulinids, bryozoans,, brachiopods, echinoderm remains, and burrowing clams. The most abundant bryzoans are fenestrate and ramose forms, fistuliporid forms being sparse. Composita, Hustedia, Wellerella, Neospirifer, and Crurithyris make up the bulk of the smooth-shelled brachiopods. More or less spinose brachiopods such as Juresania, Dictyoclostus, and Linoproductus are common. Echinoderm remains consist of crinoid stems and echinoid spines and plates. Burrowing clams include Allorisma and Aviculopinna. One trilobite pygidium, probably of a species of Ditomopyge, was found.
In the Neva Limestone, Ammovertella is not abundant, but this formaminifer does occur in the upper limestone bed at localities 1 and 2. On etched surfaces many of the limestones show sections of calcareous chambered foraminifera.
Many of the Neva Limestone strata contain large numbers of small spines, probably broken from productid brachiopods. These are so common locally that they make up 5 to 10 percent of the etched surface.
Some of the common organic associations in limestones of the Neva member are as follows:
- Ramose and fenestrate bryozoan fragments oriented with long axes parallel to the bedding, crinoid stems, and other echinoderm fragments.
- Fusulinids; calcareous, chambered foraminifers, and many small ?productid spines.
- Fusulinids and echinoderm fragments.
- Ramose bryozoans; calcareous, chambered foraminifers; and small productid spines.
- Echinoid spines and calcareous, chambered foraminifers.
Fusulinids invariably occur with some other organic particles, nowhere alone, and are concentrated in the lower 2 to 3 cm of some limestone strata, but no preferred orientation of fusulinids was observed. Masses of fusulinids are present in shales as stringers or clusters. The fusulinids are cemented together with calcium carbonate, perhaps by secondary solution of outer parts of the test. In many of the individuals, the outer part of the theca is removed and the edges of the tunnel can be seen, presumably as a result either of rolling of the tests on the sea bottom prior to incorporation in the sediment, or of secondary solution of the test.
Both the micro- and megafauna of the Neva member show a noticeable change from the content of lower members. Cavellina, Hollinella, and Tetrataxis are dominant in the Legion and Salem Point Shales, but Climacammina, Bairdia, Tetrataxis, and Glyphostomella are leading forms in the Neva member. The absence of Bairdia from lower members is noteworthy, as this genus is a long-ranging, supposedly ubiquitous form.
Within the Neva member there are important differences in the microassemblages (Table 7). The shale just above the lowest limestone bed of the Neva is dark gray and contains a large amount of selacian remains and conodonts. This shale is equivalent, possibly, to black shale zones in the Neva member farther north, but in the area studied, the upper part of this shale contains fusulinids, brachiopods, and bryozoans.
Table 7--Percentages of identifiable microfossils in shales of the Neva member.
|Locality 1||Locality 2|
|Bythocypris||5||Bryozoan fragments||11||Brachiopod spines||7|
|Crinoid stems||3||Crinoid stems||2|
|(128 individuals)||(100 individuals)||(55 individuals)|
Lateral changes--The total thickness of shale in the Neva member decreases from north to south in the area studied (Table 8). The shale-limestone ratio of the Neva north and south from the area studied was computed from the published sections of Condra and Busby (1933). At Sallyards, Greenwood County, the shale-limestone ratio is 0.79 and at Americus, Lyon County, this ratio decreases to 0.26. There is a steady increase in the ratio from Americus northward, the ratio reaching a maximum value of 0.59 at Sabetha, Kansas. At Burbank, Oklahoma, south of the type area, the ratio is 0.53, and at Ralston, Oklahoma, it is 0.28.
Table 8--Thickness of the Neva member and limestone-shale components, in feet.
As has been pointed out, black shale is not found in the Neva Limestone in the type area of the Grenola. It is possible, however, that the dark-gray shales recognized in this region are equivalent to the black shale zones farther north.
Two distinct lateral changes in the Neva member take place with respect to the chert and fusulinids. At the northernmost locality (1), a single bed of chert 0.3 foot thick was recognized, which occurs near the top of the member. At locality 2 (Pl. 4B), two layers of chert were found; a light-gray layer is in the uppermost bed of the member, and a dark-gray one near the center of the member. Five limestone beds contain chert at locality 4. Within the lowermost, black and light-gray chert nodules occur; the upper chert layers are light gray.
Thickness of limestone contining fusulinids likewise increases southward. At locality 1, three shales and one limestone contain fusulinids, but the upper 4.3 feet of the Neva member contains no fusulinids. Four limestones and two shales contain fusulinids at locality 2, and sparse fusulinids are found in the top bed of the member. At locality 4. two shales and four limestones contain this foraminifer, and one of these beds, almost 8 feet thick, contains fusulinids throughout. Fusulinids were also found in the chert nodules in this bed. The total thickness of strata containing fusulinids is 5.3 feet at locality 1, 9.8 feet at locality 2, and 14.6 feet at locality 4, a southward increase in thickness of beds containing fusulinids.
Kansas Geological Survey, Geology
Placed on web June 4, 2007; originally published June 1958.
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