Mississippian Stratotypes

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551. 7 C{D'17rvi

International Union of Geological Sciences '' SUBCOMMISSION ON CARBONIFEROUS STRATIGRAPHY

IN CONJUNCT! ON WITH

15TH ANNUAL MEETING OF THE NORTH-CENTRAL SECTION G. S. A.

MISSISSIPPIAN STRATOTYPES

Charles Col I in son, James W. Baxter anq R. D. Norby

Illinois Stare Geological Survey

H. R. Lane and Paul D. Brenckle

Amoco Production Company FIELD TRIP SCHEDULE FIRST DAY - APRIL 27

12:00 PM Osceola - meet at city square for lunch

12:45 PM Bullard-Hunt Quarries

1:45 PM Osceola North Roadcut

2:45 PM Leave Osceola for St. Louis. Shortest travel time probably can be achieved by traveling southward on Missouri Highway 13 to I-44 north of Springfield. Travel time should be about 6 hours. Those who wish to take a longer trip but see the type areas for the Sedalia and Chouteau Limestones can travel north on U. S. Highway 65 to Pettis and Cooper Counties. Those traveling eastward on I-40 will pass near Northview. In addition, there are excellent exposures south of Springfield on U.S. Highway 65.

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SEE YOU IN ST. LOUIS TOMORROW. MEET AT HOLIDAY INN, ST. LOUIS SOUTH ON LINDBURGH ROAD AT 8 AM. > \ '·

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·- ·-·-·-·-·-·-·-·-·-· 1111�IMim�ffl�ll111 3 305 1 0000 6 7573 ILLINOIS STATE GEQCXJICAL. SURVEY

FIELD GUIDEm<

MISSISSIPPIAN . STRATOTYPES

-charles ·Collinson, James-W. Baxter and -R. D. Norby

Illinois State Geological Survey

H. R. Lane and Paul D. Brenckle

Amoco Production _Company

A field trip held in connection with t� 15th Annual

Meeting of t� North-Central section Geological Society

of Merica

APriL 1981 JAN 21996 IL GEU1- �UKVEY

I Introduction

The presept booklet is not a field guidebook ip the formal sense but more accurately is a collection of notes to stimulate study and discussion of selected Mississippian outcrops that are important to the consideration of Osage an , Meramecian , Kinderhookian, Valmeyeran and Che sterian sections as series and boundary stratotype references. A general field log and schedule is given on the covers of the booklet. Arrangements fo r transportation, lodging and food are left to the participants. Inasmuch as this is essentially an informal trip please take extra care to guard against traffic, steep slopes and falling rock . Anyone who wishes to remain at an exposure after the group is finished certainly should do so and rejoin the main group wherever it is convenient . Special maps will be loaned to those who need them for guidance .

The trip is a formal activity of the SCCS Wo rking Group on the Mis sissippian of the U.S.A. We will be glad to add new name s to our mailing list.

Contents Page The Type Osagean . • • • . . 1

Osagean Biostratigraphy • 7

The Type Me ramecian • • • l3

History of the Meramec Highlands •• 14

Me rame c Stratigraphy . 14

Meramec Sections . • •• 17

Type Me ramec Conodonts •• . . -. . . . . 26

The Keokuk Limestone in the St . Louis Area. 31

The Valmeyeran Series • • 34

The Chesterian Stratotype • ...... • 41

The Kinderhookian Series ••• 51 ',•

--- LIBRARY__ ___. THE TYPE OSAGE

... .. • , H. Richard Lane and Paul L. lirenckle ;.. ..

INTRODUCTION

H. S. Williams (1891, p. 169, 172) introduced the term "Osage Group" as one of three faunal subdivisions of his Mississippian Series. It was named for outcrops along the Osage River in west-central Missouri (Williams, 1891, p. 265), although no type section was designated. He included the Burlington and Keokuk Limestones in the group because he believed faunas characterizing these two formations were present along the river. On the other hand, Keyes (1893, p. 60) noted that the Keokuk is absent even at the best exposures near the town of Osceola. In the same article, he (p. 59) proposed the term "Augusta Limestone" [group] to include the Burlington and Keokuk Limestones of southeastern Iowa. Although the type section of the Augusta more adequately defines what Williams intended the.Osage Group to embrace, Weller (1898, p. 12) .pro moted usage of the term "Osage" because of priority. Subsequently, the name Osage has gained wide acceptance throughout North America and has ..' been used as a serial subdivision (Osagean) of the Mississippian System since the publication of Ulrich (1911). However, its general usage con forms closer to Keyes ' concept of the Augusta than it does to the time stratigraphic interval representing the Osage in its type area along the Osage River. More recently, the Osage of west-central Missouri has been reviewed by Kaiser (1950) who stated that the most complete section in the Osceola area is at the now abandoned Bullard-Hunt Quarry (Kaiser 's Locality 56), about one mile west of town. Thus, although there is no forinal type section for the Osage, the Bullard-Hunt Quarry has been treated as the principal reference section. Two of our measured sec tions are located within the quarry and the third is nearby (Figure 1).

Through the years, the concept of the Osagean has been modified to include beds underlying the Burlington in both west-central Missouri and the Mississippi Valley. Ulrich (1911, pl. 29) extended the base of the Osagean downward in the Mississippi Valley by inclus ion of the Fern Glen Formation (Weller, 1906, p. 433). Since then, the lower dolomitic lime� stone beds of the Fern Glen have been renamed the Meppen Limestone by the Illinois State Geological Survey (Willman et al., 1975). --

In the type area, Moore (1928) extended the base of the Osagean downward by including in it his Sedalia Formation which he correlated with the Fern Glen. Spreng (1952) and Beveridge and Clark (1952) assigned the upp er part of Moore 's Sedalia in the type Osage to the Northview Shale FIGURE I

·- * ... ,

MILES

MISSOUHI

• ST. CLAIN COUNTY 2 and Pierson Limestone. They restricted the Sedalia in the Osceola area to beds-beneath the Northview- and suggested the Kinderhookian-Osagean boundary to be at the Northview-Pierson contact.

STRATIGRAPHY

The exposures at the Bullard-Hunt Quarry consist only of a partial sec tion of the Burlington Limestone. The base of the quarry is within the Burlington and the top is an erosional surface. A nearby section (Osceola North Roadcut, Figure 4), exposes the lower beds of the Burlington and the underlying Pierson, Northview, and Sedalia Forma tions. The Keokuk Limestone and younger Mississippian units are not present in the vicinity of Osceola. The following three sections (Figure 1) represent the primary reference for the Osage Group. They were described and sampled in November 1975 by John Baesemann of Amoco Research Center, Gilbert Klapper of The University of Iowa, and the authors. �lthough the outcrops were well exposed and accessible at that time, all but the upper part of the Bullard-Hunt Quarry II Section will be flooded by the new Harry S. Truman Reservoir.

Bullard-Hunt Quarry I

The section exposes the lower part of the Burlington Limestone, although the base of the formation is covered. It begins at the lowest outcrop above the flooded quarry floor on\ the east side of the main quarry (SEl/4, NWl/4, SEl/4, Sec. 18, T38N, R25W, St. Clair County, Missouri). The lithology and distribution of microfossils are depicted in Figure 2.

UNIT LITHOLOGY THICKNESS M F

Burlington Limestone

5 Gray dolomitic crinoidal-bryozoan pack 0. 15 0.5 stone, rubbly (algal?) zone at base. Sample 8 - whole unit.

4 Buff to gray, fossiliferous, medium to 1.68 5.6 coarse-grained, very dolomitic packstone with finer grained stringers, abundant stylolites; corals, crinoids, brachiopods. Sample 7 - 2.2 to 2.7 ft above base; Sample 6 - 1.7 to 2.2 ft above base; Sample 5 - 0.9 ft above base.

3 Sucrosic, very limy dolomitized crinoidal 0.42 1.4 bryozoan packstone. Sample 4 - lower 0.5 ft. FIGURE 2 BULLARD-HUNT QUARRY SECTION I

FM. FEET SAMPLE UNIT CONODONTS I x x x s

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=> x co 2.5 2

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1 � 0 .a ;::: Ci:' -:.; Ci:' Ci:' ·!:? § 1 ...ci. 0 � s � -� � � a ...ci...... � � �() � � -<: 0 � () ti .c:: �a �() §, c:: � () l �a 1 � .....� ., Cl � cf � q: � c 3

2 Buff, slightly limy dolomitized crinoidal 0.66 2.2 packstone/wackestone. Sample 3 - upper 0.5 ft; Sample 2-- 1.2 �o 1. 7 ft-above base .

1 Buff, fine-grained, very dolomitic 0.33 1.1 crinoidal.packstone. Sample 1 - upper 0.5 ft . .

Total measured section 3.24 10.8

Bullard-Hunt Quarry II ,;o ' . This section (Figure 3) exposes the upper part of the Burlington Lime stone. The top of the outcrop is an erosional surface covered by a Holocene regolith. The section (SWl/4, NEl/4, SEl/4, Sec. 18, T38N, R25W, St. Clair County, Missouri) starts near the floor of the quarry facing the Osage River and continues up the steep hillside to the south. The lowest bed correlates to a position 4 feet below the base of unit 5 at the Quarry I section.

UNIT LITHOLOGY THICKNESS M F

Burlington Limestone

12 Pink, medium- to coarse-grained, slightly 6.99 23.3 dolomitic crinoidal packstone, scattered chert clasts, weathers thin-bedded in places. Sample 19 - upper 1 ft. Sample 18 - 8 ft above.base.

11 Coarse-grained, dolomitic crinoidal 0.99 3.3

bryozoan packstone. Scattered chert and ' stylolites. Samples 16 and 17 - lower 1 ft.

10 Light gray, recessive, dolomiti� crinoidal 0.45 1.5 wackestone/packstone. Abundant chert.

9 Gray, medium- to coarse-grained, dolomitic 4.23 14.1 crinoidal-bryozoan packstone/wackestone, fine-grained in places. Buff to white chert layer in top of lower bed. Sample 15 - 11.1 ft above base. Sample 14 - 4.5 to 5.5 ft above base. Sample 13 - 3.6 ft above base. FIGURE 3 BULLARD-HUNT QUARRY SECTION Il

CALCAREOUS FM. FEET SAMPLE UNITI CONODONTS 'MICROFOSSILS ___,_.,...... _ 80 ___ 19

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8 Medium- to coarse-grained, dolomitized 0. 81 2.1 crinoidal-packstone, scattered brown-and buff.chert. ' Sample 12 - upper 1 ft. ·',l

7 Fine- to coarse-grained, dolomitic 5.43 18.1 crinoidal-bryozoan packstone/wackestone becoming_more crinoidal upward. White fossilif�rous chert layer at base and scattered chert nodules above . Sample 11 - uppcer 1.2 ft. Sample 10 - 9.1 ft above base . Sample 9 - 5.3 to 5.8 ft above base . Sample 8 - 4 ft above base . Sample 7 - lower 0. 5 ft.

6 Massive, gray, fine- to coarse-grained, 2.07 6. 9 dolomitic crinoidal-bryozoan wackestone, scattered chert nodules, brachiopods, abiindant stylolitic surfaces. Sample 6 - 4.9 ft above base . Sample 5 - lower 1 ft .

5 Rubbly, gray, argillaceous, dolomitic, 0.45 1. 5 crinoidal wackestone, thickens and thins laterally.

4 Gray, fine- to coarse-grained, dolomitized 0.84 2.8 crinoidal wackestone, stylolitic.

Sample 4 - upper 1 ft . Sample 3 - lower 1 ft.

3 Rubbly, gray, argillaceous, dolomitized 0. 33 1.1 crinoidal wackestone� . Sample 2 - 0. 5 ft above base.

2 Limestone as below with white chert o."21 0.7 nodules. Correlates with top of Section I.

1 Gray, medium- to coarse-grained, dolomitic 1.20 4.0 crinoidal-bryozoan packstone wi·th fine grained dolomitized wackestone stringers. Sample 1 - 1 ft above base.

Total measured section 24. 00 80.0

Osceola North Roadcut :5fop 3

This outcrop is located on the north side of County Route B, 0.9 miles west of Missouri Highway 13 and just east of the Frisco Railroad tracks 5

(NWl/4, SWl/4, NWl/4, Sec. 17, T38N, R25W, St. Clair County, Missouri). The section begins within the Sedalia and proceeds through the North view, Pierson, and Burlington. A columnar section and the microfossil distribution are illustrated on Figure 4. , UNIT LITHOLOGY THICKNESS M F

Burlington Limestone

14 Gray, interbedded coarse-grained, dolo 1.89 6.3 mitic crinoidal-bryozoan packstone and wackestone. Sample 18 - 2.2 ft above base.

" 13 Gray, medium-grained, dolomitic crinoidal- 5.34 17.8 bryozoan wackestone/packstone, stylolitic, scattered chert bands and nodules. Sample 17 - 13.3 to 13.8 ft above base. Sample 16 - 2.2 to 2.7 ft above base.

12 Buff to gray dolomitic shale. 0.09 0.3

11 Gray, vuggy, rubbly, dolomitized crinoidal 1.14 3.8 wackestone/packstone, lenses of less rubbly lithology in lower half. Equivalent to units 3 through 5 at Bullard-Hunt Quarry Section II. Sample 15 from lens at 1 ft above base. Sample 14 - lower 0.5 ft.

10 Gra�, fine- to coarse-grained, massive - 1.80 6.0 dolomitized crinoidal wackestone/packstone, abwidant stylolites and scattered chert nodules. Sample 13 - 5.5 to 6.0 ft above base. Sample 12 - 2.0 to 3.0 ft above base. Sample 11 - 1.0 to 1.5 ft above base.

9 Buff to gray, medium-grained, dolomitic, 1.74 5.8 crinoidal-bryozoan wackestone, stylolitic in lower part. Sample 10 - 1.8 to 2.3 ft above base.

8 Gray, medium-grained, dolomitic, crinoidal 0.24 0.8 packstone, streaked brown, abundant spirifers. Sample 9 - whole unit.

Total Burlington Limestone 12.24 40.8 /

Pierson Formation

7 Buff, fine-grained, skelmoldic dolomite, 1. 53 5.1 corals. Sample 8 - 4. 4 to 5. 1 ft above base.

6 Brown clay shale. 0. 09 0.3

5 Buff, fine-grained, silty skelmoldic 1.35 4.5 dolomite. Sample 7 - �.6 to 4.5 ft above base. Sample 6 - 2.6 to 3.6 ft above base.

Total Pierson Formation 2.97 9. 9

Northview Formation

4 Buff, slightly dolomitic, argillaceous, 0.75 2.5 recessive siltstone. Sample 5 - upper 0.5 ft. Sample 4 - 1.0 to 1.5 ft above base. Sample 3 - lower 0.5 ft.

Total Northview Formation 0. 75 2.5

Sedalia Formation

3 Buff, argillaceous, fine-grained, vuggy 1. 23 4.1 dolomite. Sample 2 - 3.6 to 4.1 ft above base.

2 Recessive, buff, argillaceous, fine 0.36 1. -2 grained, thin-bedded dolomite.

1 Buff, argillaceous, fine-grained, vuggy 0.45 1.-5 dolomite. Sample 1 - whole unit.

Total exposed Sedalia Formation 2.04 6.-s

Total exposed section 18. 00 60�0 z �0 -4 SEDALIA PIERSON BURL INGTO N .,, I� I I �

� .,, "' N w � VI 0- m 0 0 o 0 0 0 0 . ...

'Tl - G') c ::0 r-� fTI � Nt11•C11 ca ... l9<0 0 = ia i:iiiii Oi � ii J . c __, 0 ...... z (I' y -� w � "" '° 0 .... w ,.. I :; n �.� � � m 0 Polygnalhus commum's ( P) � >C M )(-� ,... n )> Si'phonodella sp. IP) )( x 0 Neopri'onlodus IN) z sp. � )( z 0 0 ::0 Elietognalhus laceralus (0) )( 0 � Gnalhodus lyp/cus (P) )( 0 :J: z ... ::0 en Unassigned B1 )( Pseudopolygnathus mullislrlalus I PJ )( � 0 n

/ c � �n Pala eospi'ropl«lammina parvo --- ___ n> aff.P. )( ..., lla,.. Indeterminate foraminifer )( �� 0 lla en e) �c ,.. en en 7

BIOSTRATIGRAPHY . The microfossils retrieved from the reference sections of the Osage Group are meager and poorly preserved (Pls. 1, 2). As is typical in the North American Midcontinent east of the Transcontinental Arch, pre Keokuk Osagean foraminifers and algae are very rare. Of a total of 45 samples collected, only five contained rare�calcareous microfossils which are discussed below. .Conodonts are more abundant but still rela tively rare and low in diversity. Nevertheless, the fauna is definitive and permits correlation of the type Osage t;o the Mississippi Valley as discussed below and depicted in Figure 5.

Conodonts.--Lane (1974) proposed a series of Mississippian conodont faunal units that were later emended in Lane (1978) . This faunal unit scheme has application-over most of North America and the portion of the scheme utilized in this study and its relation to the recently proposed formal zonation of Lane, Sandberg, and Ziegler (1980) is illustrated on Figure 5.

At the Osceola North Roadcut (Figure 4), a late Kinderhookian conodont fauna containing Siphonodella sp. and Elictognathus laceratus was recov ered in the Sedalia. Because of poor preservation, the fauna is assigned questionably to the isoticha-Upper crenulata Zone of Sandberg, et al. (1978) [=faunal units IF and 2 of Lane]. Samples from the over lying Northview and Pierson did �ot yield conodonts. However, in south western Missouri, the Northview contains conodonts indicative of the . �arliest Osagean faunal unit -2 and becomes as young as faunal unit.3A (Thompson and Fellows, i970). In northeastern Oklahoma the base of the overlying Pierson is as old as faunal unit 2 and becomes as young as faunal unit 6. At the type Osage, the lower part of the Burlington Limestone contains conodonts belonging to faunal unit 3B (=Lower tYPicus ,Zone of Lane et·al, 1980) and, thus, is equivalent to part of the Pierson to the-south. No conodonts diagnostic of any succeeding faunal. units or zones have been found in the upper Burlington at 'the type Osage. Representative conodonts recovered from the Sedalia' and Burlington near Osceola are illustrated on Plate 1.

Calcareous microfossils. --Calcareous microfossils at the type Osage sec tions are limited to two horizons within the Burlington Limestone. Both the diversity and total number of specimens are low. The Burlington, although dolomitized, retains its primary crinoidal-bryozoan packstone and wackestone textures whereas the subjacent Pierson, Northview and Sedalia Formations have lithologies unfavorable for preservation of cal careous microfossils. Multilocular foraminifers are confined to approx imately the same interval represented by samples 8 and 11 at the Bullard-Hunt Quarry Section II (Figure 3) and samples 17 and 18 at the Osceola North Roadcut (Figure 4) . Foraminifers in this interval include FIGU RE 5

CONOD EUROPEAN NORTH CALCAREOUS ON� CONOOONT TYP E:; MISSISSIPPI ZONES STAGES AMERICAN MICROFOSSIL OF' FAUNAS OSAGE VALLEY I SERIES ASSEMBLAGES LANE El A E 1980 L N t 1978

KEOKUK BIOTA ' exan11s 7 ( Brenckle al., t el · · KEOKUK in press) /

6 z � Q) � < g ...... : b LI.I e � anchoralis- CJ) b� 58 > ·� � lotus 0 �� II:) 5 A zz UJ \) � - -'

•�� ,____, z Cit ;1 cE (!) . �.' .z ___, < i- • ? :::> �� ? I .l.JJJ • ·� b Upp�r aJ LI.I 4 z .�· (.!) ��I typic,11$ . Ci I· t; .< q, � I CJ) � � Lower B 0 �� 3 BURLINGTON J� typicus z �'° < A -CJ) 3 < PIERSON hh ? --1 �---- z . 0:: :::> isosticha-, 2. NORTHV IEW 0 ? f- 1------1------+------i - - - - �d 'd Lt.f KINDERHOO� Upper SEDALIA IAN CHOUTEAU (PART) crsnulota

II 8

Palaeospiroplectammina aff. �· parva, Latiendothyra(?) sp. and indeterminate--forms-along With--the aoujgaliid _ - alga(?), Sta--- --�-- __ cheoides(?) sp. A second microfossiliferous horizon (sample 16_, ,Bu:t:0;;'/ lard�Hunt_Quarry� -S �ction Il) contains _only -the_ simple-bilocular _foram-. inifer Earlandia�

The Burlington in_the type area of the Osage resembles its counterpart in the MissisSippi Valley in its primary lithology and paucity of cal C!lreous -mi.crofossils. In the latter region the Burlington, along with the underlying Fern Glen and Meppen Formations, is almost d�void of cal careous microfossils. Specimens of Palaeospiroplectammina {Plate 2) similar to those in the type Osage have been found only in the Fern Glen at a single locality, Chautauqua West, along the Mississippi River. Common specimens of the non-diagnostic foraminifer Earlandia do occur throughout the area as well., as a scattering of indeterminate e1tdothyrids (sensu lato) and aoujgaliid (Mametella chautauquae, Stacheoides sp. , - Aoujgalia sp-';?) and kamaenid-algae. Yet nowhereH are seen the relatively abundant -and -diverse tournayellid and endothyrid foraminiferal faunas characteristic of Early Mississippian strata north and west of the Transcontinental Arch (Zeller, 1957 ; McKay and Green , 1963 ; Skipp , 1969 ; Brenckle , 1973; Mamet , 1976).

HRL:ksb 81085ART0079 9

REFERENCES

Beveridge , T. R. and Clark, E. L. ,'-1952 ,·A revision of the Early Missis� sippian nomenclature in western Missouri: Guidebook Sixteenth Regional Field 'Conference , The Kansas Geological Society, p. 71-79.

Brenckle, P. L. , 1973, Smaller Mississippian and Lower Pennsylvanian calcareous foraminifers from Nevada: Cushman Found. Foram. Research , Special Pub. No. 11, 82 p., 10 pls.

, 1977, Mametella , A new genus of calcareous red Algae (?) of Mis- --- sissippian age in North America: Jour. Paleont. , v. 51, no. 2, p. 250-255, 1 pl. \ \ , Marshall, F. C. , Waller, S. F. , and Wilhelm, M. , (in:..press) , Cal- --- careous microfossils from the Keokuk Limestone and adjacent formations , upper Mississippi River Valley: Their meaning for North American and intercontinental correlation: Geologica et Palaeon tologica , v. 15, 10 pls.

Chernysheva, N. E. , 1940, On the stratigraphy of the Lower Carboniferous Foraminifera in the Makorovski district of the south Urals: Soc. Nat. Moscou Bull. , n. s. , v. 48, G�l. Sec. v. 18, nos. 5-6, p.

113-135, 2 pls •

Kaiser , C. P. , 1950, Stratigraphy of Lower Mississippian rocks in south western Missouri: Bull. Am. Assoc. Petrol. Geol. , v. 34, p. 2133-2172.

Keyes , C. R. , 1893, The geological formations of Iowa: Iowa Geol. Survey, v. 1, p. f3-144.

Lane , H. R. , 1974, Mississippian of southeastern New Mexico and west Texas - a wedge-on-wedge relation: Am. Assoc. Petrol. Geol. Bull. : v. 58, p. 269-282.

, 1978, The Burlington Shelf (Mississippian): north-central United --- States: Geologica et Palaeontologica , v. 12, p. 165•176.

, Sandberg, , and Ziegler , W. , 1980, Taxonomy and phylogeny of --- C. A. some Lower. Carboniferous conodQnts and preliminary standard post- Siphonodella zonation: Geologica et Palaeontologica, v. 14, p. 117-164.

Mamet , B. L., 1976, An atlas of microfacies in Carboniferous carbonates of the Canadian Cordillera:_ _GeoL_Surv.�__ Can. BulL 255, 131 p., 95 pls. 10

McKay, W., and Green, R.� 1963, Mississippian Forminifera of the southern Canadian Rocky Mountains, Alberta: Res. Coun� Alberta Bull. 10, 77 p., 12 pls.

Moore, R. C., 1928, 'Early Mississippian formations in Missouri: Missouri Bur. Geol. and Hines, v. 21, p. 1-283.

Sandberg, C. A., Ziegler, W., Leuteritz, K., and Brill, S. H., 1978, Phylogeny, speciation, and zonation of Siphonodella (Conodonta, Upper _Devonian and Lower Carboniferous): Newsl. Stratigr.,-v. 7, p. 102-120.

Skipp, B., 1969, Foraminifera: in McKee, E. D., and Gutschick, R. C., eds., History of the Redwalr-Limestone of northern Arizona: Geol. Soc. Amer. Memoir 114, p. 173-255, pls. 16-28.

Spreng, A. C., 1952, The lower Pierson fauna of west central Missouri: Guidebook Sixteenth Regional Field Conference, The Kansas Geolog ical Society, p. 81-86.

Thompson, T. L. and Fellows, L. D., 1970, Stratigraphy and conodont biostratigraphy of Kinderhookian and Osagean (Lower Mississippian) rocks of southwestern Missouri and adjacent areas: Missouri Geo logical Survey and Water Resources, R. I. 45, 263 p. \ Ulrich, E. O., 1911, Revision of the Paleozoic Systems: Geol. Soc. America Bull., v. 22, p. 281-680.

Weller, J. M., et al., 1948, Correlation of the Mississippian formations of North America: Geol. Soc. Amer. Bull., v. 59, p. 91-196.

Weller, Stuart, 1898, Osage vs. Augusta: Am. Geologist, vol. 22, p. 16-18.

, 1906, Kinderhook faunal studies - 4. Fauna of the Glen Park --- Limestone: St. Louis Acad. Sci. Trans. v. 16, p. 435-471.

Williams, H. S., 1891, Correlation Papers, Devonian and Carboniferous: U.S. Geol. Survey Bull. 80, p. 1-279.

Willman, H. B., et al., 1975, Handbook of Illinois stratigraphy: Illinois State Geol. Survey, Bull. 95, 261 p.

Zeller, F. J., 1957, Mississippian endothyroid Foraminifera from the Cordilleran Geosyncline: Jour. Paleont., v. 31, p. 679-704, 8 pls.

HRL:ksb 81085ART0079 11

PLATE 1

All Figures are Cambridge Mark II A Scanning Electron Photomicrographs , Figs. 1, 2, 12, 13 - Polygnathus comrnunis communis Branson and Mehl. 1, 2, Upper (XlOl) and lower (X88) views, respectively, Burlington Limestone (Sample 11, Bullard-Hunt Quarry II). 12, 13, Lower (Xll7) and upper (Xl03) views, respectively, Burlington Limestone (Sample 12, Osceola North Roadcut).

3 - Ozarkodina sp. Lateral view (X89), Burlington Limestone (Sample 8, Bullard-Hunt Quarry I).

4, 5 - Gnathodus typicus Cooper. Upper (X68) and lower (X62) views, respectively, Burlington Limestone (Sample 9, Osceola North Roadcut).

6 - Siphonodella sp. Upper view (X89), Sedalia Formation (Sample 2, Osceola North Roadcut).

7, 11 - Pseudopolygnathus multistriatus Mehl and Thomas (Mor photype 2). Upper (X75) and lower (X80) views, respectively, Burlington Limestone (Sample '8, Bullard-Hunt Quarry I).

8 - Spathognathodus pulcher (Branson and Mehl). Lateral view (X86), Burlington Limestone (Sample 8, Bullard-Hunt Quarry I).

9 - Idioprioniodus furnishi (0 - element) (Rexroad). Outer lateral view (X46), Burlington Limestone (Sample 3, Bullard Hunt Quarry II).

10 - Elictognathus laceratus (Branson and Mehl). Outer lateral view (Xl02), Sedalia Formation (Sample 2, Osceola North Roadcut).

14 - Unassigned B2 - element. Inner lateral view (X64), Burlington Limestone (Sample 9, Osceola North Roadcut).

15, 16 - Polygnathus communis subsp. indet. Lower (X96) and upper (X88) views, respectively, Burlington.Limestone (Sample 15, Osceola North Roadcut).

HRL: ksb 81085ART0079

PLATE 2

The specimen in figure 1 comes from the Chautauqua west section along the Mississippi River (Brenckle, 1977, p. 254, Fig . 3); the rest are .. from sections illustrated in Figures 3 and 4 of this report. -:

1-5 Palaeospiroplectammina aff . �- parva (Chernysheva, 1940) . 1, sample 9, Fern Glen Fm. Chautauqua West Section, sagittal section, X95; 2, 3, 5, sample 9, Burlington Ls., Bullard-Hunt Quarry section II; 2, tangential - near axial section, X95; 3, tangential section of biserial chambers, X95; 5, tangential section, XlOO; 4, sample 17, Burlington, Ls ., Osceola North Roadcut section, tangential - near axial section, X95 .

' ..

HRL : ksb 81085ART0079 St. Louis Communily Coll�gr At Mrromrc

.,,- Ci) c :0 m

LEGEND

-� MEASURED SECTION 15

MfASUNEO SECTIONS @ MERAMEC RIVER BEND @ MARSHALL ROAD © MERAMEC HIGHLANDS Q�RRY MERAMEC RIVER BRIDGE @ . ® CRAGWOLD ROAD (LOWER) @ CRAGWOLD '°'O (UPPER) ® DIETERLE LANE CONTOUR INTERVAL =SO FT. WATSON ROAD @ 112 MILE

.1 KM •

,, .. ,1�,J . . ,., ..• ' ·, 13

THE TYPE MERAMEC

H. Richard Lane and Paul L. Brenckle

INTRODUCTION

The Late Mississippian Meramecian Series developed from the. concept of

, the Meramec Group which was .de.fined by Ulrich (in Buckley and Buehler, �: 1904 , p. 110) as follows:

(()) · The name Spergen Hill limestone is adopted.for the oolitic and granular limestone division of the group shown beneath the St. Louis limestone at the Meramec Highlands quarry and in the equivalent beds in the quarry at Wicks station. The Bedford stone of Indiana is derived from this formation.

(7) The Warsaw limestone·{and shales) occur at the base of the group at Mera�ec Highlands and extend northward from that point. This, together with the overlying Spergen Hill and St. Louis limestones are embraced in a group for which I propose the name Meramec group.

From the above, we interpret the type section of the Meramec Group to be in and around the Meramec Highlands Quarry. However, most authors (e.g. , Wilmarth , 1938; Thompson and Anderson, 1976) have not located the type Meramec in relation to the quarry , but have assumed that it was in a hilly area called Meramec Highlands along the Meramec River west of St. Louis. Meramec Highlands does not appear on any recent U.S. Geolog ical Survey topographic sheets or other maps of the area, although Buckley and Buehler (1904 , p. 193) gave a location for the quarry. After studying the local history we determined that "Meramec Highlands" referred to a resort and associated quarry in existence at the turn of the century.

Ulrich did not discuss the outcrops on which he based his proposal for the Meramec Group , but Weller (1908 , p. 85 , 86) described the section at Meramec Highlands which we interpret to be the type (Fig. 1, Mea.sured Sections A-C). In addition to these outcrops , recent road construction has exposed a nearly complete section of Warsaw through St. Louis strata at the Interstate 270-44 interchange about one mile southeast of the 14 quarry (Fig. 1, Measured Sections D-G, see Lane and Brenckle , 1977 , pp. 23-34). These exposures constitute primary reference sections for the Meramecian.

' HISTORY OF MERAMEC HIGHLANDS

In 1895 , the Meramec Highlands resort was opened next to the St. Louis and San Francisco railroad along the bluffs of the Meramec River west of St. Louis (Fig. 1). Associated with the resort was the Meramec High lands Company Quarry located 1/4 mile east of Meramec Railroad Depot (Fig. 1, no. 1). Originally opened to supply crushed rock for railroad construction, it was later used to provide building stone at "The High lands" and in St. Louis (Chomeau , 1963). The quarry was abandoned by the time Ulrich proposed the Meramec Group.

The resort ceased operation in the 1920's. Chomeau (1963 , p. 6) stated that in the resort's final years , "It became a common sight to find the week-end trolleys bulging with raffish crowds of undesirables. 'The Highlands ' was declared off-limits to teen-age youngsters in the suburbs and sank rapidly into a honky-tonk. The prim hops ... were long for gotten , and the inhabitants· of the area themselves were even threatened by mobsters . ..• in 1923 , voters found the polls being supervised by gangsters and managed to register their votes with shot-guns." ' After buying the property in 1926, the new owners sponsored a contest to rename the area. Ironically for students of Mississippian geology, the winning name was "Osage Hills". This toponym appears on the latest topographic map (U.S.G.S. Kirkwood Quad. , 1954 , photo revised , 1968 , 1:24 , 000) and has contributed to confusion over the location of Meramec Highlands.

STRATIGRAPHY

The term "Meramecian", proposed by Ulrich (1911), was incorporated into t�e GSA correlation charts of the Mississippian (Weller et al. , 1948) as one of four subdivisions of the·System. Although the original designa tion of the Meramec included only the Warsaw , Spergen Hill (= Salem) and St. Louis Limestones, Wilmarth (1938) and later authors have included the Ste. Genevieve Limestone. The latter overlies the St. Louis over much of southern Illinois and southeastern Missouri , but is not present at the type Meramec.

The type section at Meramec Highlands (Weller, 1908) begins in the bluff at the bend in the Meramec River south of Marshall Road (Fig. 1, Sec. A) and continues up the south side of the road (Fig. 1, Sec. B) where the Warsaw and Salem are exposed. The remainder of the type section (Fig. 1, Sec. C) outcrops in the ab andoned Meramec Highlands Quarry south of Big Bend Road on the east side of Interstate 270. Keokuk Limestone

The beds underlying the type Meramec belong to the Keokuk Limestone.- " The formation was n�med by Owen (1852, p. 91) for ..� gray, cherty limestones, which form a wall of rock washed by the Mississippi, below the Keokuck Landing [Iowa]." Only the upper part of the formation is present at Meramec; Highlands, although older parts of tlie Keokuk are exposed directly to the west in the vicinity of Peerless Park. Weller (1908, p. 86, 87) assigned his Beds 1 and 2 to the formation. Bed 1, comprised of blue-gray cherty limestone, is typical of most of the Keokuk throughout the Mississippi Valley. It corresponds with Units 1 through 6 at our Meramec River Bend Section (Fig. 2). Weller's second unit of intercalated shales and limestones is transitional with the overlying Warsaw and is equivalent to Units 7 through 23 at Meramec River Bend. His total thickness of exposed Keokuk (38 ft) agrees almost exactly with our measurements (38.1 ft) at Meramec River Bend. We selected the base of the Warsaw at the point where shales predominate and--the limestones.-become --mor-e-ar-gillaceous-and-less- -ed.noidal and cherty. It approximates the position chosen by Weller (1908).

Warsaw Shale

The Warsaw Shale or second Archimedes Limestone was named by Hall (1857) for exposures of interbedded lim�stone and shale near the town of Warsaw, Illinois. It was separated from the Keokuk by the shaly Geodi ferous and Magnesian limestone beds of Owen (1852). Based on megafaunal studies, Van Tuyl (1922, p. 185) recommended that the base of the Warsaw be extended down to include the geode beds. This concept of the Warsaw ,(lj is now generally accepted.

In the area of the type Meramec, the Warsaw lacks the Geodiferous and Magnesian limestone beds and instead can be divided into a lower fossil iferous shale and limestone sequence and an upper dark shale. Weller's (1908) Beds 3 through 8 belong to this formation. Our Units 24 to 36 at Meramec River Bend are assigned to the lower Warsaw. The upper part of the Warsaw is poorly exposed over most of the area, but can best be observed at the nearby Cragwold Road Section (Units 21-23 of Lane and Brenckle, 1977).

Salem Limestone

The Salem Limestone was named by Cumings (1901, p. 233) for a "gray oolitic quarry stone" above the Harrodsburg Limestone and beneath the Mitchell (now St. Louis Limestone, Nicoll and Rexroad, 1975) at the Salem Stone and Lime Company Quarry one mile west of Salem, Indiana. Until recently, the name Salem has been widely used throughout the Mis sissippi Valley for any carbonate, whether oolitic or not, occurring 16 between the Warsaw and St. Louis. At Meramec Highlands the beds assigned to the Salem by Weller (1908, p. 85, 86, Beds 9-16) are com posed of dolomites , shales , and various limestones. The interval dif fers sufficiently f�om descriptions of the type Salem that we have placed the formation name in quotation marks. Revisory work by Baxter (1960) and Lineback (1966, 1972) on the interval traditionally assigned to the Salem in southern Illinois may have application in the St. Louis area , but further study is necessary.

Two distinct intervals can be recognized in the Salem in the Meramec Highlands area. A lower interval consists of brown , partly dolomitized, cross-bedded , crinoidal-bryozoan wackestones to grainstones. Inter bedded with these are thick, gray-to-brown shales and earthy dolomites changing vertically to cross-bedded , crinoidal, brachiopodal and , in some beds , superficial oolitic packstones and grainstones. Units 1-26 at Marshall Road (Fig. 3) and Units 1-21 at Meramec Highlands Quarry (Fig. 4) constitute the lower part of the Salem. The upper part con sists mostly of a buff-to-brown , fine-grained , highly cross-bedded grainstone with abundant buff cannonball-shaped chert nodules. It is represented by Units 27 and 28 at Marshall Road and Units 22-24 at Mer amec Highlands Quarry.

St. Louis Limestone

The St. Louis Limestone of Engelmann (1847) originally was used for beds between the top of the Warsaw and the base of the Chester. Ulrich in Buckley and Buehler (1904) first used the term "St. Louis" in its modern sense. No type section was designated , but the formation was named for exposures in quarries and bluffs along the Mississippi River at St. Louis. The St. Louis at Meramec Highland�- consistS--o.f- di-verse car bonate lithologies varying from light gray stromatolitic boundstones , intraclastic packstones , and buff-brown earthy dolomitic packstones in the lower part to brown-to-buff earth.dolomites and gray-buff superfi cial oolitic packstones and grainstones in the upper part.

Ste. Genevieve Limestone

The Ste. Genevieve Limestone is absent in the vicinity of the type Mer amec, but is present approximately 25 to 30 miles to the northeast at the Missouri Portland Cement Company Quarry (Martin and Wells , 1966 ; Thompson , 1966) and near Alton, Illinois (Collinson and Swann , 1958). Ulrich (1911) included the Ste. Genevieve in the Chesterian , but Weller (1920) included it in the Meramec Group. This latter placement has been supported by Sutton and Weller (1932), Wilmarth (1938), and Swann (1963) as well as many other recent publications. DESCRIBED SECTIONS

MERAMEC RIVER BEND SECTION

NW 1/4, NE 1/4, Sec. 15 , T44N , RSE , Kirkwood 7. 5' Quadrangle , St. Louis County , Missouri

UNIT LITHOLOGY THICKNESS M F

Warsaw Shale

36 Limestone as in Unit 32 with 0.1 ft 0.24 0.8 shale stringer in middle. Sample 17 - upper 0.4 ft.

35 Cover - probably shale. · 0.15 0.5

34 Lithology as in Unit 32. 0.15 0.5

33 Cover - probably shale. 0.91 3.0

32 Lithology as in Unit 301, no chert ; 0.43 1.4 · brachiopods; Sample 16 - upper 0.5 ft.

31 Cover - probably shale. 0.76 2.5

30 Buff , medium-grained , crinoidal-bryozoan 0.61 2.0 grainstone , partly chertified. Sample 15 - upper 0.5 ft.

29 Cover - probably shale. 0.15 0.5

28 Buff , argillaceous , unevenly bedded , 0.58 1.9 medium-grained , crinoidal-bryozoan packstone. Sample 14 - lower 0.5 ft.

27 Buff clay shale. Sample 13 - whole unit. 0.37 1.2

26 Cover - probably shale. 0.79 2.6

25 Buff to brown , argillaceous , crinoidal 1.13 3.7 bryozoan packstone becoming more thin bedded in upper 2.0 ft , interbedded with buff , calcareous shale. Sample 12 - 1.5-2.0 ft above base. MERAMEC RIVER BENO

LEGEND ; •t

LIMESTONE DOLOMITE SHALE, SAND SILT BURROWS CLAYSTONE �l®@@I � �1�€;1 � CHERT CANNCNBALL STROMATO CALCITE- INTRACLASTS SUPERFICIAL . CHERT LITES FILLED VUGS OOLITHS

-2� MICROFOSSIL SAMPLE LOC. ANO NO.

z 0 .... <( Cl) w .... :E - °' °' z 0 w ::::> u.. Cl) �17- 34-36 33 ' --- 32 � 31 � � � -1.s- � � � --- 28 � -- 1:1 � 26 � .-- � � --- 25 - -� 24 23 -- 22 -10- --'2T --- �- 9 � � � SCALE ------� � 5 .....J.li5 � � 15 10- 12 4 -- � ,-- � -r 10 3 -.,-- Q 6 � 2 -.s- 5 � 5 --- (/) 4 -- � :=3:: � 0 FEET- METERS 2

--- I .. � -1- MERAMEC RIVER (LOW WATE R) FIGURE 2 18

24 Cover - probably-shale. o. 76 2. 5

Total exposed Warsaw 7. 00 23. 1

, Keokuk· Limestone

23 Buff to gray, slabby , crinoidal-bryozoan 0. 52 1. 7

packstone ; corals. Sample 11 - lower 0. 5 ft.

. 22 Buff , calcareous shale interbedded .with 0. 88 2. 9 buff to gray, medium- to coarse-grained, crinoidal-bryozoan packstone to grainstone , gray chert nodules in lower 1. 0 ft ; trilobites , brachiopods , corals. Sample 10 - 0. 2-0. 9 ft above base.

21 Cover - probably shale. 0. 24 0. 8

20 Brown , crinoidal-bryozoan packstone , 0. 49 1. 6 . abundant light gray chert. nodules. Sample 9 - lower 0. 5 ft.

19 Brown weathering shale. \ 0. 06 0.2

18 Gray chert bed with 0. 1 ft limestone bed 0. 18 0. 6 at top ; abundant bryozoans.

17 Cover. 0.34 1. 1

16 Gray t� buff , thin- to massive�bedded , 0. 58 1. 9 medium- to coarse-grained , crinoidal bryozoan grainstone , glauconitic;

brachiopods. Sample 8 - lower 1. 0 ft.

15 Buff , recessive , interbedded crinoidal 0. 27 0. 9 bryozoan packstone and shale, buff chert at top. Sample 7 - 0. 5 ft above base.

14 Speckled gray and white, coarse-grained , 0. 21 0. 7 crinoidal-bryozoan packstone , buff chert.

13 Same as unit 9. 0. 31 1.0

12 Light gray , coarse-grained, crinoidal 0. 18 0. 6 bryozoan grainstone.

11 Buff, bedded chert. 0. 18 0. 6 ' .

10 Light gray , fissile weathering, fine 0.27 0.9 grained , crinoidal-bryozoan grainstone; rare solitary rugose corals. Sample 6 - upper 0.5 ft.

9 Light gray thin-bedded , cherty, crinoidal 0.43 1.4 bryozoan packstone with shaly partings.

8 Light gray to buff , fissile weathering , 0.43 1.4 coarse-grained , crinoidal-bryozoan grainstone.

7 Light gray , thin-bedded chert with many 0.52 1. 7 shaly partings. A 0.5 ft thick, coarse grained encrinite bed at 1.0 ft above base.

6 Buff , fine-grained , crinoidal-bryozoan 0.79 2.6 grainstone with scattered chert grading up to buff to white crinoidal chert with scattered limestone; crinoids , brachiopods and bryozoans in lower 0.5 ft. Sample 5 - lower 0.4 ft.

5 Light gray, slabby, coarse-grained , . 0.67 2.2 crinoidal-bryozoan grainstone with brown weathering shale partings , scattered disseminated chert. Sample 4 - 1.0 ft above base.

4 Light gray, slabby , medium- to coarse 0.70 2.3 grained , crinoidal-bryozoan grainstone , abundant disseminated buff chert. Sample 3 - lower 0.5 ft.

3 Highly chertified, crinoidal limestone. 0.46 1.5

2 = Cover. 1.98 6.5 20 ·�

I Buff , rubbly, fine- to medium-grained , 0.91 3.0 crinoidal-bryozoan packstone to grainstone, abundant light gray to white disseminated chert weathering dark brown. Sample 2 - upper 0.5 {t. Sample I - lower 0.5 ft.

Total exposed Keokuk II.SS 38. I

Total section I8.SS* 61.2

*Note : Because of rounding off when changing feet to meters , the metric total does not equal the sum of the individual units.

MARSHALL ROAD SECTION S:t'opS

NE I/4, NW I/4, SE I/4, Sec. IO, T44N , RSE , Kirkwood 7.5 ' Quadrangle, St. Louis County , Missouri

UNIT LITHOLOGY THICKNESS M F

Salem Limestone

A few more feet of higher strata are exposed to the south but were not measured.

28 Buff to brown , thin-bedded , fine-grained 3.I2 10.2 grainstone , cannonball chert nodules near top, mostly inaccessible.

27 Gray to buff , cross-bedded , fine- to 1.28 4.2 medium-grained grainstone, coarse-grained at base, scattered chert lenses.

26 Buff to gray , argillaceous dolomite inter 1.43 4.7 bedded with dolomitic fissile shale.

25 Brown , massive-bedded , argillaceous , 3.00 9.9 earthy , fine-grained dolomite , partly laminated , scattered brown chert nodules in middle. MARSHALL HOAD

z 0 t- Cl) <( w t- � - a:: a:: z 0 -w :::> u.. Cl)

26 � �

......

' 24 (.) � 23 � 22 � � 21 -...... � � Q: SCALE �

= � 15 s

10 . -� 3 10 2 s

0 0 FEET METERS

COVE RED FIGURE 3 21

24 Buff , porous , fine- to medium-grained , 0.53 1.75 crinoidal packstone, chert nodules at top; bryozoans , brachiopods.

, 23 Buff to brown , fine- to medium�grained 1.34 4.4 crinoidal grainstone; abundant brachiopods near base.-

22 Gray to buff , thin-bedded , earthy dolomite, 0.52 1. 7 very fossiliferous.

Section c�ntinues up onto east side of Interstate 270 next to highway bridges.

21 Dark gray to brown , highly cross-bedded, 2.59 8.5 brachiopodal-crinoidal packstone to grain stone, thins laterally and alters to buff dolomite; scattered solitary corals , spiriferid and rhynchonellid brachiopods.

20 Gray to buff , fine-grained dolomite. 0.15 0.5

19 Same as unit 16 . 0.61 2.0

18 Buff , dolomitic siltstone\ , earthy 0.30 1.0 appearance .

17 Brown to buff , very argillaceous packstone, 0.67 2.2 shaly partings; scattered brachiopods.

16 Dark gray, slightly dolomitic, fissile 0.91 3.0 shale, mostly covered.

15 Covered. 0.43 1.4

14 Buff , bryozoan-rich dolomite. 0.15 0.5

13 Brown to buff , fine-grained packstone. 0.64 2.1

12 Buff , earthy , fine-grained dolomite, 0.12 0.4 skelmoldic porosity.

11 Brown , medium-grained packstone to 0.18 0.6 grainstone .

10 Gray to buff , cross-bedded , bryozoan 1.60 5.25 packstone, scattered chert lenses at base; crinoids , brachiopods. 22

9 Brown to buff wackestone grading laterally 0.67 2.2 into brown , earthy dolomite , skelmoldic porosity.

8 Buff , argillaceous , bryozoan .packstone, 0.73 2.4 abruptly altered laterally to buff , earthy dolomite , skelmoldic porosity.

7 Covered. 0.40 1.3

6 Buff , rubbly, argillaceous , fossiliferous 0.40 1.3 packstone, becoming less rubbly and argillaceous upward.

5 Brown, massive-bedded, fossiliferous 1. "45 4.75 packstone to grainstone , argillaceous partings , scattered surface silicification, pinpoint porosity; brachiopods.

4 Buff to gray, argillaceous , friable 0.21 0.7 packstone.

3 Buff, very calcareous shale grading 0.09 0.3 laterally to argillaceous lime�tone.

2 Buff , argillaceous , bryozoan-brachiopodal 0.61 2.0 packstone , shaly partings , undulatory bedding.

1 Buff, argillaceous , earthy dolomite , 0.38 1.25 skelmoldic porosity and limonite-filled vugs; crinoidal and bryozoan debris.

Total section 24.39* 80.5

MERAMEC HIGHLANDS QUARRY SECTION Sfop '

NE 1/4, NW 1/4 , SE 1/4, Sec. 10 , T44N , R5E , Kirkwood 7.5' Quadrangle, St. Louis County , Missouri

UNIT LITHOLOGY THICKNESS M F

St. Louis Limestone

40 Light gray, medium-grained , fossil 1. 90 6.3 fragmental-superficial oolitic grainstone. Sample 18 - upper 1.0 ft. 23

39 Gray to buff, silty, fossiliferous pack 0.39 1.3 stone, shaly in upper part . Samp;Le 17 -

lower 0.7 ft . · ·

38 Light gray 'to buff, fossil fragmental 0.42 1.4 superficial oolitic grainstone. Sample 16 � lower 0.7 ft .

37 . _Intraclastic packstone, medium-grained 0.60 2.0 matrix, light gray chert nodules .

36 Buff, argillaceous mudstone to packstone, 0.60 2.0 inaccessible .

35 Buff to brown, platy, -sandy-siity, 1.35 4.5 dolomitic packstone, top surface undtilatory as seen in exposure across - interstate; · bryozoans,- ·brachiopods . Sample 15 - 3.5 ft above base.

Section transferred north to base of Unit 35 under the railroad and Big Bend Road overpasses .

34 Wackestone as below, buff chert nodules . 0�30 1.0 \

33 Gray to buff, crinoidal wackestone to 0.27 0.9 packstone, argillaceous partings; brachiopods, bryozoans, echinoid. debris.

32 Gray to buff, stromatolitic boundstone 0.45 1.5 grading up into fossiliferous wackestone .

Sample 14 - lower 0.3 ft .

31 Buff, very argillaceous, crinoidal pack 0.24 0.8 stone, fissile weathering, abundant secondary quartz in top 0.2 ft, rubbly appearance .

Section transferred west to trench next to Interstate 270 highway.

30 Gray to buff, fine-grained packstone. 0.52 I.7

29 Gray to buff, stromatolitic boundstone . 0.12 0.4

28 Gray to buff, fine- to medium-grained 0.21 0.7 wackestone to packstone. MEHA MEC HIGHLANDS Qf.JA HH Y

en .... - � w- a.: z w ::> � en � �

�� g ooo 0 40 0., 0 o o 0 o 0 .. o 00 0 oI� 0 I o�I o o -- --- ...... 38-39 - o o o ,.., o o lo o 01 O o O g al0G .,10.,0,0 37 '°') -T- -1- 36 ...... - . . . �-......

...... 35 � I • /• • -- 0 A A .<>. .<>...... ,.... ,...... - n ,.... " " "" ,...... 28-34

I I - ....: - 27 '°') I � - � r'\ r'\ I""\ 25 � -..... --- 24 . ' �. I / @ 7 /@ / 23 (.)

t> • - • �I 2 10- I { '2 -. @ • � � -, . \ �--�I I I --\ @ @ @ 21 - ' I I A I A I t;,. I I> 20 � A A � -- � � A I> a t;,. I> I> /:;. � I 18 - '4, Q:: l -- , , 17 ..... ( / -- I / -/ I I I I - I � - \ 16 SCALE =:l � ....__ r -r- I IY - 5 15 0 J o o 0 � / � 0 o 15 " 0. 0 o. O' 'i'\ �o r '°') - · o o o o 0 0 .o OJ - -s o • 10 3 - � 0 ID 0 14 1 � 2 I ' I I -- - 5 -, - II I I 9-13 , - - - - o_ , l _,_ --8 I FEET METERS t"T- ·- - r:-i- -7 - - 6 """"5 r ' / / / , -r- - -1-- - r..: - -=-1 - 3 _,_ � 1- 1 /- I- _1_ COVERED �-fl>'i- :- FIGURE 4 24

27 Buff , slightly sandy , fine- to medium- · 1.68 5. 6 grained crinoidal packstone , slabby at top. Sample 13 - 3. 0 ft above base.

26 LighV gray, intraclastic packs tone , matrix 0. 15 0. 5 fine-grained and slightly sandy , intra clasts of silty mudstone. Sample 12 - whole unit.

25 Gray, fine- to medium-grained wackestone 0. 51 1. 7 grading into stromat.oli tic bounds tone.

Total exposed St. Louis 9. 79 32. 3

24 Buff , slightly sandy , highly cross-bedded, 3. 06 10. 2 fine-grained grainstone , slabby near top, scattered buff cannonball chert nodules; brachiopods. Sample 11 - 5.0 ft above base.

23 Buff to brown , fine-grained dolomite , buff 0. 60 2. 0 cannonball chert.

22 Buff , slightly sandy , highly cross-bedded , 2. 37 7. 9 fine-grained grainstone , buff cannonball chert nodules ; scattered brachiopods. Sample 10 - 4. 0 ft above base.

21 Buff to brown , earthy packstone , recessive , 1.05 3. 5 abundant buff cannonball chert nodules.

20 Buff , fine-grained grainstone , abundant 0. 69 2. 3 light gray-to-buff chert nodules and lenses. Sample 9 - upper 0. 5 ft.

19 Covered. 0. 36 1. 2

18 Light gray, fine- to medium-grained , 2. 97 9. 9 crinoidal-bryozoan grainstone to packstone , chert nodules near top ; brachiopods , rugose corals. Sample 8 - 3. 0 ft above base.

17 Buff , porous , fine-grained , limy dolomite, 1.02 3. 4 abundant calcite-filled voids and scattered shell fragments. 25

16 Buff to brown , cross-bedded, crinoidal 2.28 7.6 bryozoan grainstone; brachiopods; lower 0.7 ft , buff , fossiliferous , dolomitic wackestone lensing laterally into the grainstone .' Sample 7 - 3.6 to 4.1 ft above base.

15 Buff to brown, slightly sandy , cross 1.86; 6.2 bedded , fine-grained , crinoidal-superficial oolitic grainstone to packstone; rugose corals, abundant endothyrids , brachiopods at top. Sample 6 - 0.5 ft above base.

14 Buff to brown, cross-bedded, medium I.SO s.o grained, crinoidal-bryozoan grainstone to argillaceous packstone , superficial ooliths , crumbly weathered surface; brachiopods , gastropods . Sample 5 - upper 0.5 ft .

13 Covered. 0.27 0.9

12 Light gray to buff , slightly sandy , 0.06 0.2 crinoidal-superficial oolitic packstone. Sample 4 - whole unit .

11 Same as unit 9. 0.09 0.3

10 Buff , very argillaceous , brachiopodal 0.33 1.1 wackestone, shaly partings .

9 Buff , limy , fine-grained dolomite , 0.24 0.8 skelmoldic porosity; fossil fragments .

8 Brown, argillaceous , medium-grained , 0.72 2·.4 crinoidal-bryozoan packstone; abundant brachiopods . Sample 3 - 1.2 to 1.7 ft above base.

7 Buff , argillaceous , cross-bedded , medium 1.02 3.4 grained packstone, dolomitized in upper part; brachiopods .

6 Covered. I.OS 3.5

5 Buff to brown, argillaceous , bryozoan 0.76 2.5 crinoidal packstone , skelmoldic porosity, partly dolomitized and covered. 26 '•

4 Buff, fine-grained dolomite, skelmoldic 0. 18 0. 6 porosity ; scattered fossil fragments .

3 Light gray to buff, mediwn-grained, 0. 81 2.7 bryozoan-c;inoidal grainstone to argillaceous packstone . Sample 2 - 0.7 ft above base.

2 Covered . 0. 30 1.0

1 Buff to brown, argillaceous, medium- to 0.93 3.1 coarse-grained, crinoidal-bryozoan packstone, partly dolomitized, slabby at top ; scattered rugose corals . Sample 1 - 2.0 ft above base.

Total exposed Salem 24.76 81. 7

Total section 34. 55* 114. 0

TYPE MERAMEC CONODONTS

Previous Work: Branson and Mehl (1941} first described conodonts of Middle Mississ.ippian age from three loc·a lities in the Mississippi Valley . 'Although they believed that their faunas were from the Osagean Keokuk Limestone, Rexroad and Collinson (1965 , p. 2,4) noted that the former authors ' Troy and Sylvan Beach localities are, respectively, . Salem and Warsaw, and thus Meramecian i.n age . Branson and Mehl 's other locality, Calwood, yielded a stratigraphically leaked fauna from clay stringers within the Burlington and are of uncertain origin . The studies of Rexroad and Collinson (1963 , 1965) represent the most compre hensive Mississippi Valley Meramecian· conodont studies . Their type Mer amec Warsaw-Salem faunas come from Marshall Road (Rexroad and Collinson, 1965 , p. 4, Fig . 2) which is the combined Meramec River Bend and Mars hall Road localities herein. In addition, their Keokuk-Warsaw contact is somewhat above· ·that selected in this study . St. Louis faunas have not previous ly been reported from the type Meramec, but Thompson (1966) reported conodonts from the Salem, St. Louis, and Ste . Genevieve forma tions at the Vigus North, West Lake, and Missouri Portland Cement quar ries in the northern part of St. Louis county . In addition, Rexroad and Collinson (1963) documented St. Louis faunas in the Illinois Basin.

Conodonts Faunal Units: Three conodont faunal units can be recognized in Meramec age strata, two of which are present at the type Meramec exposure. The lowest one corresponds with the combined Taphrognathus varians-Apatognathus Zone Collinson et al. (1971) , the upper part of Fauna! Unit 7 of Lane (1974) , and the upper part of the texanus-Zone of 27

Lane , Sandberg and Ziegler (1980) . A second and higher subdivision corresponds with Fauna! Unit 8 of Lane, 1974 (approximately equal to Apatognathus scalenus-Cavusgnathus Zone of Collinson et al., 1962) . Three subdivisions of this fauna! unit can be recognized and these are :

(1) A lower interval characterized by the occurrence of the Taphrognathus-Cavusgnathus transitional form below the appear ance of Anchignathodus scitulus .

(2) A middle interval characterized by the occurrence of Taphrog nathus-Cavusgnathus transitional form with Anchignathodus sci tulus .

(3) An upper interval above the range of the Taphrognathus-Ca vusgnathus transitional form.

The highest conodont faunal subdivision _in the Meramec , possibly becoming as young as early Chester, is Fauna! Unit 9 of Lane (1974) . This fauna! unit is not found at the type section of the Meramec because the late Meramecian is not developed there. However , we have recovered it from the Ste . Genevieve Limestone at the abandoned Federal Quarry, Little Rock Landing , north of Ste . Genevieve . The fauna! unit is char acterized by the appearance of Rhachistognathus n. sp.

(= Spathognathodus n. sp. of Thompson and Goebel , 1968 , p. 43 , Pl . I, Figs . 9, 15-17) and Gnathodus homopunctatus . The interval is distinc tive in much of North America where it occurs in strata that correlate with not only the Ste . Genevieve Limestone, but perhaps younger Cheste� rian strata as well. Besides its published occurrences in the subsur face of Kansas (Thompson and Goebel , 1968) , in the Rancheria Formation of New Mexico (Lane, 1974) , and in the Sycamore Limestone of southern Oklahoma (Ormiston and Lane , 1976), the fauna unit is also known in our collections from the Moorefield Formation of northeast Oklahoma and the Lisburne Group of St . Lawrence Island and the Brooks Range of northern Alaska .

Conodont faunas retrieved from the type Meramec sections are listed on Figures 5, 6, and 7.

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REFERENCES

Baxter, J. W., 1960 , Salem Limestone in southwestern Illinois: Illinois State Geological Survey, Circ. 284, 32 p . • Branson , E. B. and Mehl , M. G. , 1941, Conodonts from the Keokuk forma tion: Denison Univ. Bull. , Jout. Sci. Labs. , Vol. 35 , p. 179-188.

Buckley, E. R. and Buehler, H. A., 1904 , The quarrying industry of Mis souri: Missouri Bureau of Geology and Mines , Vol. II, 2nd Series , 371 p.

Chomeau, M. B. , 1963 , Meramec Highlands: Kirkwood Historical Review , v. 2, p. 3-6.

Collinson , C. , Rexroad, C. B. , and Thompson , T. L. , 1971 , Conodont zona tion of the North American Mississippian: Geol. Society of America , Mem. 127 , pp. 353-394.

---, Scott , A. J. , and Rexroad, C. B. , 1962 , Six charts showing biostratigraphic zones and correlations based on conodonts from the Devonian and Mississippian rocks of the upper Mis sissippi valley: Illinois St. Geol. Survey, Circ. 328, 32 p.

and Swann , D. H. , 1958 , Field Trip No. 3, Mississippian rocks of Western Illinois: GSA Field Trip Guidebook , St. Louis Meeting , 1958 , p. 21-52.

Cumings , E. R. , 1901 , The use of Bedford as a formational name : Jour. of Geology , v. 9, p. 232.

Engelmann , G. , 1847, Remarks on the St. Louis Limestone: Am. Jour. Sci. , 2nd Series, v. 3, p. 119-120.

Hall, J. , 1857 , Observations upon the Carboniferous limestones of the Mississippi Valley (Abs. ): Am. Jour. Sci. , v. 23 , p. 187-203.

Lane , H. R. , 1974 , Mississippian of southeastern New Mexico and west Texas - a wedge-on-wedge relation: AAPG Bull., Vol. 58 , pp. 269-282.

--- and Brenckle, P. L. , 1977 , The type section of the Meramecian Series: Guidebook for Field Trips, Vol. 1, North-central GSA , Car- bondale, 34 p. 29

, Sandberg, C. A. , and Ziegler, W. , 1980, Taxonomy and phylogeny of --- some Lower Carboniferous conodonts and preliminary standard post- Siphonodella zonation: Geologica. et Palaeontologica , .v. l4, pp. 117-164.

Lineback , J. A. , 1966, Deep-water sediments adjacent to the Borden Silt stone (Mississippian) Delta in southern Illinois: Illinois State Geol. Survey; Circ. 401, 48 p.

---, 1972, Lateral gradation of the Salem and St. Louis Limestones (Middle Mississippian) in Illinois: Illinois State Geol. Survey, Circ. 474, 21 p.

Martin, J. A. and Wells, J. S. , 1966, Middle Ordovician and Mississip pian strata , St. Louis a.nd St. -Charles Counties, Missouri: Guide book MPG Annual Meeting} Missouri Geol. Survey and Water. Re sources Report of Investigation 34, p. 1-37.

Nicoll, R. S. and Rexroad, C. B. , 1975, Stratigraphy and conodont paleontology of the Sanders Group (Mississippian) in Indiana and adjacent Kentucky: Indiana Geol. Survey, Bull. SI, 36 p.

Ormiston , A. R. and Lane , H. R. , 1976, A unique radiolarian fauna from the Sycamore Limestone (Mississippian) and its biostratigraphic

significance: Palaeontographica , Abt. A, Bd•. 154 , pp. 158-180.

Owen, D. D. , 1852, Carboniferous rocks of southern and western Iowa , in report of a geological survey of Wisconsin, Iowa , and Minnesota , Chapter 3: Philadelphia , Lippencott , Grambo and Co. , p. 90-140:.

Rexroad , C. B. and Collinson , C. , 1963, Conodonts from the St.· Louis formation (Valmayeran series) of Illinois , Indiana , and Missouri: Illinois St. Geol. Survey, Circ. 355, 28 p.

and , 1965, Conodonts from the Keokuk , Warsaw, and Salem formations (Mississippian) of Illinois: Illinois State Geol. Survey , Circ. 388, 26 p.

Sutton , A. A. and Weller, J. M. , 1932, Lower Chester correlation in western Kentucky and Illinois: Jour. Geology � v. 40, p. 430-442. Swann , D. H., 1963, Classification of Genevievian and Chesterian (Late

Mississippian) rocks of Illinois: ·"' Illinois State Geol. Survey,

. . Report of Investigation 216, 91 p. JO

Thompson, T. L., 1966, Late Meramecian conodont faunas from the Fort Bellefontaine and Vigus North Quarries, St. Louis County, Mis souri: Guidebook AAPG Annual Meeting, Missouri Geo! . Survey and Water Resources, Report of Investigation 34, p. 42-48. ,

___ and Anderson, K. H., 1976, The Mississippian System in The Strati graphic Succession in Missouri: Missouri Geol . SurveY"; Sup . 1, v. 40, 85 p.

and Goebel, E. D., 1968, Conodonts and stratigraphy of the Merame

---cian stage (upper Mississippian) in Kansas: State Geol. Surv . of Kansas, Bull . 192, 56 p.

Ulrich, E. O., 1911, Revision of the Paleozoic Systems: Bull . Geol. Soc. of America, v. 22, p. 281-680 .

Van Tuy!, F. M., 1922, The stratigraphy of the Mississippian formations of Iowa: Iowa Geological Survey, Annual Reports, 1921 and 1922, v. 30, p. 33-349.

Weller, J. M., et al ., 1948, Correlation of the Mis sissippian formations of North America: Bull . Geo!. Soc. Arn. , v. 59, p. 91-198.

Weller, S., 1908, The Salem Limestone : Illinois State Geo!. Survey Bull . 8, p. 81-102 .

___, 1920, The geology of Hardin County and the adj oining part of Pope County: Illinois State Geol . Survey, Bull . 41, 416 p.

Wilma rth, M. G., 1938, Lexicon of geologic names of the United States (including Alaska): U.S. Geological Survey Bull . 896, 2396 p.

HRL : ksb 81085ART0105 31 The Keokuk Limestone in the St . Louis Area

Paul Brenckle and H. Richard Lane

. Throughout the Mississippi Valley, the Keokuk Limestone is composed pre - dominantly of cherty , crinoidal-bryozoan grainstones and packstones . In

the St . Louis area, from the type Meramec (Figs .. 1, 2) to Elsah, Illi nois (Figs . 3, 4) , .. the formation may be subdivided nearly equally into lower gray and upper buff-colored units . The lower part of the gray unit · contains a very cherty do lomitic zone (Fig. 4) stratigraphically equivalent to the Montrose Chert . It separates the Keokuk from the underlying Burlington Limestone as far north as the type area of the two formations ' in southern Iowa . The beds in the upper part of the buff unit become increasingly argillaceous and form a transition zone with the overlying Warsaw Shale . The contact is placed arbitrarily at the appearance of thin calcareous shales .

The top of the ·gray-unit -is - marked-by -a ..cdiscontinuous zone of limestones which in both lithology and diversity of calcareous microfossils are atypical of the Keokuk . At the Peerless Park sections (Figs . 1, 2) in the type Meramec area, this interval is about 1 meter thick and contains oolitic and superficially oolitic grainstones and sandy , fossil frag mental packstones . Nearby, the beds change to highly cross-bedded , ·sandy , fossil fra-gmental-pelletoidal grains tones exceeding 2.5 meters in thickness . These strata have been tentatively correlated with the Short Creek Oolite of southeastern Kansas by Baldwin (1953) and Voss (1963) . and may be related to the oolitic zone described from the upper Keokuk in Ste. Genevieve County, Missouri, by Weller and St . Clair (1928) .

Although the calcareous microbiota in the top of the gray unit at Peer less Park has not yet been studied in detail , a cursory examination shows that it contains many of the 'elements found at the same level near Elsah (Brenckle and Marshall, 1979 ; Brenckle et al., in press). In this -- area, the collective term "Fo:tam Bed" (Fig. 4 , Elsah West section) has been applied to the strata in the upper part of the gray unit that con tain abundant calcareous microfossils . These beds are predominant ly sandy grainstones and packstones containing ooliths , megafossil frag ments , pelletoids , foraminifers and algae . A few are dolomitized pelle toidal-calcisphaerid-spicular packstones. Laterally, these beds change to the echinodermal-bryozoan grainstones/packstones typical of the Keokuk and lose the diverse microbiota. The distribution of calcareous microfossils in the Foram Bed and other units of .the Burlington , Keokuk and Warsaw is presented in Figure 5 and 6.

The microfossil content of the Foram Bed is unusual in that the taxa Eoendothyranops is spiroides , �· scitula, Koninckopora tenuiramosa and Skippella redwallens is have, unt il recently,. never been recognized in beds older than Meramecian or Visean. Interestingly, Fenneman (1911, p. 21, 40) mentions that there is a 2 or 3 foot bed of chert-free lime stone about 50 feet below the top of the Keokuk in the type Meramec a+�� (Peerless Park) which carries a megafauna with affinities to the S��Il''' JAN 21996 IL GEuL. �URVEY 32

(Salem) Limestone . From its strat igraphic position, the bed belongs within the calcareous microfbssil zone at the top of the gray unit . Obvious ly, there is strong facies control over the distribut ion of organisms within the Keokuk , and many of the taxa occur abundant ly only in overlying Meramecian units where environmental conditions were more favorable for their proliferation . In terms of the standard Dinantian sequence of Belgium , the Foram Bed fits within the middle Visean . A more precise correlat ion is not possible at this time because there are not enough elements in common between the two areas . However , archae discids , which were not found at Elsah, may be present in the calcareous microfossil zone at Peerless Park and could provide a closer tie to the Dinant ian.

The occurrence of this biota in the middle of the Keokuk is significant in that it indicates there is no major change in foraminiferal faunas across the Osagean/Meramecian boundary . Previous attempts at posi tioning the boundary outside the type area using calcareous foraminifers may be inaccurate because of the false assumption of what elements com prise late Osagean/ early Meramecian faunas . Furtherinore , the calcareous microfossils show that the Tournaisian/Visean boundary of western Europe does not correlate to the Osagean/Meramecian boundary as advocated by Weller et al . (1948) and others , but falls lower within the Osagean beneath the Foram Bed . In fact , the youngest conodont faunas at the top of the Tournais ian in Belgium contain Scaliognathus anchoralis Morpho type 2 of Lane , Sandberg and Ziegler, 1980. Its descendant , �- ancho ralis Morphotype 3, has not been found in Belgium but is known to occur near the top of the Fern Glen Limestone in Dennis Ho l low at the type Valmeyeran (Lane , Sandberg and Ziegler, 1980, p_. 139) and in the Pierson Formation of southwestern Missouri (Thompson, 1967, p. 28-29 ; Thompson and Fellows , 1970, p. 150-151, 156-157) . Thus , in the Mississippi Val ley-Ozark Up lift area, the Tournaisian/Visean boundary should occur below the appearance of Scaliognathus anchoralis Morphotype 3 at a posi tion within the Burlington Limestone of southeastern Iowa, the upper Fern Glen Limestone of southern Illinois and the Pierson Limestone of southwestern Missouri . This placement of the boundary is lower than that at the Burlington-Keokuk contact in southeastern Iowa and western Illinois , as suggested by Brenckle; Lane and Collinson in 1974.

., ' -.

fl ' ,,tir .. , "· , •._r, · ..' , ..., •/,, ,

Fig . 1: Locality map of Keokuk measured sections at North (38° 32' 24" N, 90° 291 13" W) and South ·(38° 32' 21" N, 90° .29' 19" W) Highway Drives ; Peerless Park, St. Louis County , Missouri. Base map : Kirkwood Quadrangle (Missouri) , 7.5 minute, 1954 edition , U. S. Geological Survey . I f II, r ..._,. ... I ii r '" �� .,..•i r'lt'

L(\� � �c::: � ""'� �· z ". z -0 OQ O O ""'- G> CD -i -i � enl-'N ::u ==""'Tlc ro �· •• s;"< J::oo """ C) n M m m "'Tl ""'""'- M ::r' )>C l>. C � �· 0 CJ) z CJ) z � OI-'. � ::I 0 (') c�::u ::uc� en """\ m m ...... ce. 0 °'tJ 1-'rD C� 0 � o en El I 1 n � � I �� 11 S: 1 METERS ro () � � I o.. :;<:: en 0 - I ::U I l\l OJ � �· � � I I I I I �O � �. r 1 · ::i 2 I CJ) 1 I I �:>;"O O / 0 01 - � ::I CJ) r 0 en I l> V)� � 1 r ::u I FE ET �tilUen m ro en ::r' I O z I-'� � 1 c ro �· m-i CJ) � 0.. ::I 1 ::u OQ I };; r � � � � � l> l> l>t> I> l> l> C> l> l> l>I> (') l> C> I> l>I> t> t> I> I> m � t> -.....: I> I> l> t> t> l> C> I>C> 0::u � I> � C> C> l> l> I> I> C> C> C>C> I> I> [> r:.t:,. I>t> I> t> I> C> � l> p.. t>l> C> l> C> I> I> l> 0 � C>I>C> """\ � l> I>I> I> t> t> l>I> !> t> l> t> t> I> l> I> l> I> l>l> I>

I �' GRA y UNI T BUFF UNI T t � KEO KUK LIMESTONE IO WA

>C :; MEASURED SECTION

Keokuk 4-- ..., EXTENT OF SAMPLING OF FORAM BED

CO NTOUR INTERVAL : 100 FEET

. o.. ___ _... _ __11111 1 KM �---�--lllllliill!/2. Ml.

Fig. 3: Locality map of Keokuk measured sections at (1) Principia (NE 1/4, SE 1/4 Sec. 20, T6N, RllW) and (2) Elsah West (NE 1/4, NE 1/4 Sec . 19, T6N , RllW) , Jersey County , Illinois. Base map : Elsah Quadrangle (Illinois-Missouri) , 7.5 minute, 1954 edition, U. S. Geological Survey. (from Brenckle et al ., in press) METERS EI53 EL:l [ZJ L:=J lZ:d 1 ( UPPER) LIMESTON E DOlOMITf SANO SILT SHALE scrv;;- � --5 - SPI.. NUM8U & LOCAT ION CHERT

- FEET 1 (LOWER)

II- r I- :£1 (MIDDLE)

- -

u. u. :::> co -9 -- - I v;_, -

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FORAN BED -1�

Fig . 4: Columnar sections showing lithologies and stratigraphic positions of samples at (1) Principia and (2) Elsah West measured sections located in Figure 3. (from Brenckle et al ., in press) '''lr' ,afl �· ''!'' ( •\, , '�·_f"'l I

B FORMRT ION u R KEOKUK WRRSRW L. 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 . 2 � 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 Indet . Aoujgal l aceoe x x x x x x x x x x x x x x x x x x x x x x x x x x x Earl andia clavatul a gp . x x x x x x x x x x x 7 x x x Earl andia elegans gp. x x x x x x x x x x x x x x Earlandia moderata gp. x x x x x X: x x x x x x x x x x x 7 x x x Priscel la prisca gp, ·x x x x x x x x x x .xx 7 x x x x x x x x x x x x x x x x Tubisal ebra ruf icoronae x Aphral r,Jsla mat thewsi 7 7 x Dlpl osphaerJna lnCl84JQIis x Earlandia vu lgaris gp. x Endo thr,Jra spp . x x 7 7 x x 7 ? x 7 x x 7 x Pseudo taxis spp , x x 7 x 7 x x ? x Tetrataxls spp , x x x x x x x x x x x x x x x x x x x x x x x x x x Asphal t.? cordl l lere'ISiS? x x x x x x x x x x x x x x x x Tetratax ls sp .1 x 7 x x x Hame tel la chautauquae x 7 x 7 x 7 7 ? ? ? ? x x Spumi sat ebra sp umosa x x Indet. Salebrldoe x x x Endothr,Jra obsoleta gp. 7 x x x x Aoujgal ia ? sp . x x x Globoen do thr,Jra pJasae x x x Ep istacheo ides spp , x x Stacheo ides cf . tenuls x 7 x

Fig . 5: Occurrences of calcar�ous microfossils at the Principia measured section from samples located in Fig . 4. (from Brenckle et al ., in �� ress) FORMAT ION KEOKUK

F. . 1 3 4 5 6 7 8 9 � B. Indet .Aoujgol iaceae x x x AouJgal la 7 sp. x x £artandl a ctavatul a gp. x x £ar landia etegans gp. x x £a rl andla modera ta gp. x x £n dotrn.;ra spp . x x Fours tonel la 7 sp. x Prlsce l la prisca gp. x x x AouJgal ia variablt is x Aphral ysla matthewsi x Asphal tina 7 cordl l lerensis? x Ca lcisphoera sp, x Dosyctads x DI pl osphoerina inaequa l Is x £ar landia minima gp. x Earlandia vul garis gp . x En doth�ra obsot eta gp . x £oendoth�ranopsis sc itu(a x ? Eoen doth�ranopsis spiroides x Eoendo th�ranopsis 7 sp. x Ep istacheoides sp.1 x Fours tone tla sp . x Globoendo th�ra piasae x KonI nck opora tenul ramosa . x Hametel la chautauquae x Hi tcheldeania nicho lson i x Paracal igel l oldes 7 sp. x Parathurammlna spp . x Principia cf . c:Jonbassica x Priscel la laxo-Form is x Protot..mbella el l ip tlca x Pseudoommodiscus 7 sp. x Pseudo taxls spp . ? Radiosphaerid calcispheres x . � !! Indet. Salet>ridae x --'i ... Sklppel la redwal lensis x ? Spumlsal ebra 5Pf,lnosa x Stacheoides cf . congesta x Tetrataxis spp . x x Fig . 6: Occurrences of calcareous microfossils at the Elsah West measured section from samples located in Fig . 4. Occurrences in the Foram Bed (F.B.) are a composite of 21 samples collected both at and lateral to the measured section as shown in Fig. 3. (from Brenckle et al ., in press) 33

REFERENCES

Baldwin, W.F.J. , Jr ., 1953, The geology of the Kirkwood Quadrangle, Mis souri : Unpublished Master's thesis , Washington Univ ., St . Louis .

Brenckle, P. , Lane, H. R. , and Collinson, C. , 1974, Progress toward reconciliation of Lower Mississippian conodont and foraminiferal zonations : Geol. , v. 2, p ..433 -437 , 1 pl.

and Marshall, F. C., 1979, Day 3, stop 2:in Collinson, C., Norby , R. D. , Baxter,' J. W. , and Thompson , T. L. , Stratigraphy of the M�s sissippian stratotype : Upper Mississippi Valley U.S.A. :9th Internat . Cong . Carbon . Strat . and Geol ., Urbana, ·1979, Field Trip 8, p. 54-57.

, Waller , S. F. , and Wilhelm, M. , (in press) , Calcareous microfossils from the Keokuk Limestone and adj acent formations , upper Mississippi River Valley : Their meaning for North American and Intercontinental correlation : Geologica et Palaeontologica, v. 15 , 10 pls.

Fenneman , N. M. , 1911, Geology and mineral resources of the St . Louis quadrangle, Missouri-Illinois :U.S. Geel. Surv. , Bull . 438 , 73 p.

Lane , H. R. , Sandberg, C. A. , and Zeigler, W. , 1980, Taxonomy and phylo geny of some Lower Carboniferous conodonts and preliminary standard post-Siphonodella zonation : Geologica et Palaeontologica, v. 14, p. 117-164 .

Thompson, T. L. , 1967, Conodont zonation of lower Osagean rocks (Lower Mississippian) of southwestern Missouri: Missouri Geological Survey and Water Resources , R. I. 39 , 88 p.

and Fellows , L. D. , 1970, Stratigraphy and conodont biostratig raphy of Kinderhookian and dsagean (Lower Mississippian) rocks of southwestern Missouri and adj acent .areas : Missouri Geological Survey and Water Resources , R. I. 45 , 263 p.

Voss , J. T. , 1963, Burl ington and Keokuk Formations in the upper Missis sippi Valley area : Unpub lished Master 's thesis , St . Louis Univ. , St . Louis .

Weller, J. M. , et al., 1948, Correlation of the Mississippian formations of North America : Bull. Geol. Soc . Am ., v. 59 , p. 91-198.

Weller, S. , and St . Clair, S. , 1928, Geology of Ste . Genevieve County, Missouri: Missouri Bur . Geol . and Mines , v. 22 , 2nd Ser. , 352 p.

PLB :h 81098ART0068 SOUTHWESTERN ILLI N OIS, MISSISS IPPIAN EAST CENTRAL MISSOURI

STRATIGRAPHIC (/) Q. w w (!) :::> a:: 0 FORMATIONS MEMBERS w � a:: UNITS (/) (/) (!)

Grove Church Sh. - . . Goreville Ls. Kinkaid Cove Hill Sh. Limestone NORTHWESTERN ILLINO IS, Negll Creek Ls. NORTHEAST ERN MISSOURI Degonia Ss. Ford Station Ls. Clore Fm. ett Ss. z Tyg Coro Ls. <( a:: Palestine Ss. -

(/) > Allard Ls. w (/) _J Menard Ls. - w w Scottsburg Ls. a:: Wolche Ls. a:: 3 w z Waltersburg Fm. (/) w (/) a.. <( Vienna Limestone - :::> -

a:: -(/) 0 a:: FORMATIONS MEMBERS Tar Springs Ss. :::> 0 a:: w 0 z (!) (/) - 1-- z Glen Dean Ls. <( (/) .....J (/) - - .....J (!) Hardinsburg 1 Ss. - w � a:: 3 :c w CD <( Haney Limestone � ::,,::: (.) 0 Fraileys Shale Ste. Genev ieve \ 0 Big Clifty Ss. J: Limestone - Beech Creek Ls...... St. Louis z Cypress Ss.

z Limestone -<( <( a:: Reelsville Ls. - � w f- � Ridenhower Fm. Sample ss. z W (.) Salem a.. tseaver Hend I s. w -w Limestone en Bethel Ss. � <( �5 Downeys Bluff Ls. (!) <( z Yankeetown Ss. a:: ,; <( �net erv111e ls. - Sonora Fm . Renault Limestone w a:: Levios Ls. � w .? Upper Member Aux Vases Ss. Rosiclare Ss. z Joooo Mhr. >- Warsaw z -<( Karnak Ls. w Shale :;oar Mountain :;s. Lower Member <( > v - � w Ste. Genevieve Ls. � a:: .....J > <( w w > Keokuk >- z St. Lou is Limestone Montrose w c <( Limestone w Chert � ...J (!) � Rocher Mbr. Cedar Fork Ls. <( <( Chalfin Mbr. > (/) Burlington Haight Creek Fults Mbr. 0 Salem Limestone Limestone Limestone Kidd Mbr. Horrodsburo Ls. Dolbee Creek Ls. Ullin Limestone Romp Creek Ls. - z z z Keokuk Limestone

<(- -<( - - - J: _J -<( ,___ � � Ii:_J � o-J: Burlington 0 0 Z 0 0 0 0 Limestone :c � :c :c a:: a:: a:: Fe rn c;len Fm. � w w >- Hannibal Shale ••annqn LS. :t:Z w 0 0 a w

THE VALMEYERAN SERIES

The Valmeyeran Series was proposed by We ller and Sutton in 1933 in a textbook by R. C. Moore who soon thereafter, at the urging of Lowell Lauden , rejected the term. Lauden used the great differences in Keokuk and Warsaw echinoderms as his basi.s for maintaining Osagean and Me rame cian Series. The Illinois Geological Survey, Weller's own organization , rejected Valmeyeran until 1956 when continued difficulty in use of the Osagean-Meramecian nomenclature brought about the adoption of Valmeyeran . The Indiana Geological Survey adopted Valmeyeran in 1970. The term has had a stable and useful tenure ever since . Osagean and Meramecian today enjoy widespread usage , as series or groups , but suffer uneven interpretation . Many place their mutual boundary at the top of the Keokuk , others place it at the top of the Warsaw .

The series (Weller and Sutton , in Moore , 1933, p. 261-262) is named for Valmeyer, Monroe County, near which much of the series is exposed. It is the middle series of the Mississippian. System and includes formations assigned to two series (Osagean and Merame cian} in other areas . The Valmeyeran Series underlies most of central and southern Illinois and includes strata from the top of the Chouteau Limestone upward to. the · base of the Shetlerville Member of the Renault Limestone (Swann , 1963) . The series is thickest , ove r 1800 feet , in southeastern Illinois, and it thins to 600 feet or less before being truncated by erosion in northern Illinois. It originally covered all of northern Illinois , as 200 feet of Valmeyeran strata are preserved in f.ault blocks in the Des Plaines Di sturbance .

. \ The Valmeyeran is characterized by lateral changes due to depositional pinchouts and lateral gradation . Here in the type area, the Valmeyeran is predominantly carbonates. In central Illinois the Burlington and Keokuk Limestones pinch out eastward and the lower part of the Valmeyeran consists of the thick Borden .. Siltstone . Eastward , in southeastern Illinois , the Borden is replaced as the : dominant unit by the very thick Ullin Limestone and then by thick siliceous

: limestone of the Fort Payne ·Formation . · · The sediment of- the Borden Siltstone was transported from the northeast by a major river and deposited in the inland sea as a delta that spread to and overlapped the Keokuk and Burlington carbonates . ::.. The deep-water, sediment-starved basin adjacent to the delta was later filled ' with Fort Payne and Ullin sediments (Swann et al., 1965; Lineback , 1966 , 1968a , 1968b) .

The ove rlying Salem and St . Louis Limestones are more persistent across the basin than the underlying_ units , but they, too , show facies that reflect water depth. Massive biocalcarenitic Salem grades laterally_ northward into fine-grained evaporite-bearing carbonates of the St. Louis (Lineback , 1972) . Near the top of the Valmeyeran Series, the members of the Ste . Genevieve Limestone show rapid facies changes and the contact with the underlying St . Louis Limestone is stepped up and down in response to local lithologic changes.

Because of the complex facies variations in the Valmeyeran Series , knowledge of the relations between the many units has grown slowly, and the classification has been repeatedly changed. FORMATION SERIES

+.> ------::::i /' ..... I '.:.. I ...,... I ...u.. S EM LIMESTONE u 1 AL 4-- I """ I ..i I"'I""' Limestone , as bel ow; sol ution pits at top. 0 \:.. I"' ..l "O I""- I I c: QJ _J .:!-_J � _J .':'_j - - .µ "' ""'" "' "'" I I "'-I"'- I LLI j -11 I '"' I Limestone, brown ish gray, ma ssive, medium-grained, shaly; _, I I I 6 I fossiliferous at base; cross-bedded styolitic; scattered I I ..'.l I I chert nodul es. oo=-1-"'-J --1�-1= Limestone , brown ish gray, fine-grained , th in-bedded , cherty.

Limestone , brownish gray , fi ne to coarse-grained , massive, shaly - - - 1 --1 --1 --1 - streaks at top. I I I I I I I I ! I 6 I 6 I 6 I 6 I Limestone, brown , very cherty. Limestone , brown , fine to medium-grained , ma ssive; very dolomitic, . { I I® I I weathers soft; small wh ite cal cite pockets; many smal l coral s, I© I I I® I bryozoans, and brachi opods weather loose on outcrop surface. ( I 10 I I I Limestone , brown , medium to coarse-grained , me di um to thick-bedded; I I I I dol omi tic, vuggy at base. [ I I I --k Limestone, light brown , medium to coarse-grained ; thin irregul ar �1 -1 � beds; cherty in upper part . �1 - 1 - I I ' I 6 I I .A" I _, I I / I " L-----1I I _, II I z .:, I I I I b::::---kJ.. ' I � imestone, brown ish gray, coarse-grained, ma ssive, fossiliferous ; � w I I ----, I _J ross-bedded , shaly at base . I ;: 2 _J """' 1.11. _ .... I'-'"I 1.11. 1 "'-II ULLIN LIMESTONE --<» - -- "' ------dol omi tic, weathers shaly; numerous pink dolomite crystal vugs. Limestone , gray, fine-grained, argillaceous; massive beds 1 =®- -.. __;-- / I I I alternate wi th shaly zones ; very fo ssiliferous with large I I ·1 I spiriferid brachiopods; thin shel l breccias. I I Limestone, gray, fi ne-grained , argi llaceous ; weathers shaly; ' --- I - , - 1- fi lls channel s in unit below; pink dol omite crystal vugs. - -• " --" I II .I " ' -" I I I !!Limestone , gray, massive, fi ne to coarse , very fossiliferous ; weathers tan and medium to thi ck-bedded; shaly at base ; fenestrel linid bryozoans paral lel to beddi ng give rock a 1 :::;.._,.>" I I 5 � � Jami n ated appearance . ��I� I I . -1-1- 1- 1 - Limestone , grayi sh buff , fi ne-grai ned, very argi llaceous - - - I r I I � M - e - - 10 I - - - I ' r - -_L r_- S t ery c l s, bl ocky. e I I I I 1�!� ;�� r F e I I :::::J_ =i: Limestone , grayi sh buff, fine-grained, very argi llaceous , s ::..t.= =J::-t:::t:_!_ e }-<::::::.I c::a...... 1.- c::>---o-1-0 __,,r- massive, �1eathers shaley, wi th pink crystal vugs . t ,..---'-- ;,;.---___::r=w---=r::_--;-=,_ -L.= ·, Shale, gray transitional to above ; ve rtical burrows sand and i � 0 ) -'--- _, _L_ -.L_ current bedding. 0 -- · - ---'- - - -...... __ -- . Limestone , gray, bryozoan-crinoid coquina interbedded with �hal e; sandy in pl �ces with gray chert. imestone , gray with thin shale interbeds. c==t I I I � c I I I I Limestone , gray bryozoan-crinoid coquina wi th shale and r hert, abundant brachiopods. -'---- }.L:--1...... __ I I I � =__i_= =i= =..J..:_ = =---i_ hale, gray , cal careous bl ocky , thin limestone. f <::> I c:::. I <=::> I c=::. l�l c::::> l c::::> � Limestone , gray , bryozoan-cri noid coquina wi th some ool ite, Mb ;:=9 cross-bedded, gray shale interbeds , gray chert .

E Columbia Roadcut SE� NE� SE� and NE� S � SE� Sec . 22 and SW� NW� SW� and SW� SW� Sec . 23, T. l S., R. 10 W. , Columbia Quadrangle, Monroe County, Illinois. 35

The conodont and foraminiferal faunas of the Valmeyeran have been discussed in preceeding pages. The macrofaunas like them are di stinctive . Large spiri ferids and productids are characteristic. Syringothyris is common along with the Spirifer grimesi (Burlington } - Spirifer logani (Keokuk } lineage . The Fern Glen fauna , wh ich is partly shared with the lowe r Burlington , in clude s Leptaena an aloga (which is at the top of its range} . Dictyoclostus fernglenensis , Spirifer subtexta, Spirifer rowleyi and Brachythyris chouteauensis , Echinoconchus alternata, Brachythyris suborbicularis and Re ticularia pseudolineata first appear in the Burlington . In the Keokuk , Dictyoclostus craw fo rdsvillensis, Orthotetes keokuk and Spirifer logani are characteristic. Q_. keokuk , Echinoconchis biseriata , Rhipidome lla dubia , Camerotoechia mutata , Tetracame ra subcuneata , Spirifer keokuk and Eurnetria ve rneuiliana all first appear in this formation . Marginirugus magnus marks the highe st part of the Keokuk and the lower parts of the Warsaw .

The bryozoans Stenopora , Lioclema , Fistulipora, Glyptopora , Cystodictya , Cyc lopora , Fene stella, Hemitrypa , Polypora , Penniretepora , Taeniodictya and Worthenopora are characteristic of the Warsaw . Lioclema punctaturn and Archimedes wortheni are common indices. Brachythyris subcardiformis continues upward from the Keokuk . Echinoconchus alternatus, E. biseriatus, Spirifer pellaensis , Re ticularia setigera and Eumetria ve rne�liana with �· subcardiformis are the most common brachiopods. Spirifer bifurcatus and §_. washingtonensis are char acteristic of the Salem Limestone along with Spirifer littoni. The St. Louis faunas are somewhat re stricted. The corals , Lithostrotion proliferurn and Lithostrotione lla castelnaui , are common in some facies. The main brachiopods are Spirifer littoni and Dictyoclostus tenuicostatus whe reas Linoproductus ovatus is common in some upp ermost beds .

The Ste . Genevieve has two m�in index species, the crinoid Platycrinites penicillus and the distinctive brachiopod Pugnoides ottumwa . In addition , Orthotetes kaskaskiensis, which is common , first appears in the formation and continues into the Chesterian . Diaphragmus cestriensis appears in the upper part . Spirifer pe llaensis is relatively common . 36 ·�"f,)f'1 i' Columbia Roadcut . Warsaw , Ullin , and Salem Formations . SE\ NE\ SE\ and NE\ SE\ SE\ Sec . 22 and SW� NW� SW� ·and SW� SW� Sec. 23, T. 1 S. , R. 10 W. , Monroe County , Illinois.

The Warsaw Shale , the Ul lin Limestone (named by Lineback in 1966) and the Salem Lime stone are exposed in this long cut along Illinois Highway 3, about 1 mile south of Columbia. The Warsaw Shale is exposed at the we st end of the cut and the road gradually ascends th�ough the Warsaw , Ullin , and Salem in a dis tance of about 0.5 mile . The Valmeyeran rocks here are transitional between the northwestern Illinois-southeastern Iowa sections, wh ich contain the Warsaw Shale and the Sonora Sandstone , and the Illinois Basin sections , wh ich contain the Borden Silt stone and the Ullin Limestone . The Warsaw Shale here consists of alternating thin , gray , fine to coarse , fossiliferous , argi llaceous lime stones (wackestones and mud stones) and blue-gray shale . The Warsaw is laterally continuous eastward with the Borden Siltstone . Less than 30 miles east of this point , the Burlington and Keokuk Lime stones that underlie the Warsaw pinch out basinward along a carbonate bank front and the Warsaw-Borden thickens to over 600 feet . The Warsaw grade s westward into argillaceous carbonates and here is tran sitional upward with the Ullin . The Warsaw is about 60 fe et thick in this area. The Ullin Lime stone is over 600 feet thick in the Illinois Basin , but thins we stward from there across the Borden de lta to the Burlington-Keokuk carbonate band of western Illinois. The Ullin here contains gray , fine to coarse , somewhat argill.aceous , fossiliferous lime stone s with ab undant echinoderm , bryozoan , and brachipod remains (packstones to grain stone s) . Where thicke r in the basin , the Ullin is more dominantly a crinoid-bryozoan calcarenite . The lower part of the Salem Limestone , which is exposed in this roadcut , consists of brown ish gray , fine- to coarse-grained limestone containing cornminuted fossil debris (grainstones) . Cross-bedding is apparent in many units and is especially conspicuous near the top , at the east end of the cut . Parts of th e Salem are argillaceous and dolomitic. The fossil fragments in the Salem often have oolite-like overgrowths.

The exposure is of special intere st to us because it exhibits the Wa�saw-Ullin contact (Warsaw-Salem of most authors ) which, until 1956, had been the official I.S.G.S. Osagean-Merame cian boundary for more than 30 years . It was a source of dis agreement between such stratigraphers as E. 0. Ulrich , R. C. Moore , and Lowe ll Laudon on one hand an d Stuart We ller and J. Marvin We ller on the other.

Rexroad and Collinson (1965) studied Warsaw-Salem conodonts in th is area and reported faunas from the entire section . Gnathodus texanus and Taphrognathus varians dominate the faunas . Both occur throughout the section but G. texanus is most abun dant in the very argillaceous sediments whe reas I. varians is abundant in the limestone s. Range-wise there is no sharp differentiation between the Warsaw and Salem faunas here .

Foraminifera are present at several places in the section . The Warsaw has a distinctive faun a throughout . It contains Endothyra obsoleta , E. prisca, Archaedi scus sp . and Tetraxis sp . The Ullin Limestone carries few foraminifera

-- 37

but the Salem has abundant Globoendothyra baileyi in the lowe rmost , uppermost and middle beds where they generally are accompanied by the algae Aouj galia and Stacheia? The differentiation between Warsaw and Salem faunas is clear whereas those of the Keokuk and Warsaw are essentially the same .

Brachiopods are common to abundant in the lime stone beds here . Syringothyris subcuspidata , Brachythris subcardiformi s, and Spirifer washingtonensis are common spe cie s.

Bryozoa which are common are listed unde r the discuss ion of the Dennis Hollow Section . Dennis Hollow. Along the north side of Illinois Highway 156 is the south half of Sec. 2, T. 3 S. , R. 11 W. , Valmeyer Quadrangle , Monroe County .

One of the finest geologic sections to be observe d anywhere in Illinois is exposed along Dennis Hollow , which cuts across the northeast flank of the Valmeyer Anticline . Outcrops are not continuous and in part are obscured by vegetation but by piecing together exposures in the bed of the hollow and its branches and others on the hillsides, a practically complete section from the Salem to the Kimmswick Limestone can be studied. Devonian , and Silurian strata are missing, however. A generalized section of the strata exposed along the hollow as de scribed by L. E. Workman in a 1949 A.A.P.G. guidebook is as follows :

Upper end of road cut : Thickness :feet

Mississippian System: Warsaw Formation :

5. Shale , calcareous , yellowish to gray ; limestone lenses ••- 13 Keokuk Formation : 4. Limestone , shaly, cherty , glauconitic , light greenish-gray 16 3. Limestone , cherty , gray , crinoidal . 3

2. Shale • • • • • • • . • • • • . • . • • • 2 Burlington Formation : 1. Limestone , cherty , light gray, coarse . 3

Total • • • · • • • . • • • • • • • 37

In ravine back of house , north of road, halfway down the hollow :

Mississippian System : Burlington Formation :

10 . Limestone , cherty , medium to light gray , coarse • 35

9. Chert , yellow, carious . • • • • • • . • . • 2

8. Limestone , cherty, coarse, 3/4 covered. • • • . • 40

7. Limestone , light g�ay , finely crystalline ••.. 3

6. Limestone , very cherty , light buff-gray , coarse • 75

5. Covered • • • • • • . • . • • • • • • • 5 Fern Glen Formation : 4. Limestone , mottled gray and red, very fine to coarse . 19

3. Chert , flesh colored, translucent .•.•.••••• 0.5 2. Lime stone , argillaceous , cherty, red and gray , very fine

to coarse • • • • • . • • • • . • • • . • • . • • • 10 Ordovician System: Maquoketa Formation :

1. Shale , calcareous , blue and gray mottled ..••••••• 2

Total . • • 191

West end of road cut at the east. side of Valmeyer :

Mississippian System: Fern Glen Formation :

5. Weathered lime stone , mostly chert. • . • • • . • . • . • 14 Ordovician System : Maquoketa - Formation : 4. Shale , greenish- an d brownish-gray , weathe red red at top;

limestone nodules. • . • • • • • . • • • • . . • • • • • 35 3. Limestone , cherty , buff earthy to crystalline , silicified

small fossils. • • • . . • . . . • . . . . • • • • . • • 2 Thickn� ss feet

Fernvale Formation : 2. Limestone , brownish- to bluish-gray, coarse , fossiliferous , Rhynchotrema capax • • • • • • • • • • • • • 1.2 Kinunswick Formation : 1. Lime stone , light gray , very coarse , Receptaculites • 6 Total . • • • • • • • • • •. • • • • • • • • • • • • • 58

Localities 1, 2, 3: Top of section .

The highe st road-cut (Locality 1) shows the transition between the Ke okuk and Warsaw formations . There is no sharp break but chert becomes less conunon and the limestones become more argillaceous . In this region , the lower part of the Warsaw contains much gray , more or less calcareous , shale of the type exposed here . Higher in the formation there is much limestone interbedded in the shale and near the top Spirifer washingtonensis becomes a conunon fo ssil. Such strata may be seen along a lane which leads up the hillside north of the pavement a short distance east of this road-cut . The next out crop down the highway (Locality 3) is typical of the Burlington and Keokuk lime stones as they are deve loped in the region . Fossils that are sparingly present show that both are repre sented in this very cherty series of beds . The limestone layers are light gray and more or less crinoidal . They contain chert in varying proportions, up to 50 percent or more .

i Locality 2 is in the first gu lley west of Locality No . 1 and is important because it repre sents an upward extension of Locality No . 3. It also carries the conodont Taphrognathus varian.s which first appears in the Keokuk .

Locality No . 5, which is located half way down Dennis Hollow , exhibits a very accessible complete section of the FerJl. Glen overlying a ve ry thin section of Chouteau (not identified above by Workman) and a short section of Hannibal (identified by Workman as Maquoketa) .

DENNIS HOLLOW

600

500

400 Alluvium

I MIL.E

From Kansas Geological Society Guidebook , 1939 \J f II I/ I/ ff ,, // I/ ff II // II // ,, // // II 11 \111� ,/!I/ �·N .�-

• a 773 L,

Sections Described at Dennis Hollow FORMATION SERIES WARSAW SHALE Limestone, buff/light brown interbedded with calcareous brown shale and dark gray chert

Spi ri fer washingtonensis is conmon in the upper part of the section .

INTERVAL

Shale, buff/light brown, calcar£Ous, very fossiliferous with bryozoans, .1. crinoids and brachiopods

Shdl e, buff to light brown, cal careous, fossiliferous with discontinuous light brown bryozoan cal careni te limestone beds . The "Bryozoan Bed" of Stuart Wel ler.

�e stone, light gray to light buff; shale, light brown, cal careous . KEOKUK LIMESTONE

Limestone , light gray , may be sandy, crinoidal ; interbedded with dark gray to ol ive and light buff chert.

--- Limestone , light gray irregularly interbedded wi th chert. --- Limestone , very light gray , coarsely crinoidal ; interbedded wi th wh i te and buff mottled chert; very large solitary coral s; large cri noid stems and large spiriferi ds in lower part.

Limestone , very light gray , coarsely cri noidal ; interbedded wi th wh ite to light buff chert.

Limestone , very light gray to buff, coarsely cri noidal , very large cri noid col umnal s; chert, white mottl ed dark ol ive.

Dennis Hollow Locali ty No . J, Warsaw .Roadcut . Center NW!.i SE�· Sec ·· · . · 2, T. 3 S., R. 11 w. , Valmeyer Quadrangle, Monroe County, Illinois. ;; FORMATION SERIE:S KEOKUK LIME STONE Limestone, buff, fi ne-grained, very cherty, quartz geodes 5 FEET

Limestone, gray, fine- to coarse-grained , fossiliferous, cherty z <( a:: w dolomitic, cherty Limestone, buff , > w �stone, buff, fine-/ med-/coarse-grained, cherty, fossiliferous, irregularly bedded, chert nodules irregular � ...J Limestone, buff , fine-grained , cherty � Lim;stone, buff, fine-/coarse-grained, fossiliferous, crinoid debris in � � iner bryozoan debris matrix . · Limestone, buff, fine-grained ; chert , gray, "fossiliferous

Limestone, buff, dolomitic, cherty; chert, gray, fossi liferous ---

Limestone, gray, fine-/medium-grained ,·crinoidal-bryozoan debris

��::..

Dennis Hollow Local ity No . 2, Keokuk in Gulley. SW� NW� SE� Sec . 2, T. 3 S., R. 11 W. , Valmeyer Quadrangle, Monroe County, Illinois. FORMATION SERIES

KEOKUK LIMESTONE

Limestone, very light gray, massive, crinoidal

Limestone, very light gray, dolomi tic, crinoidal , irregular, interbedded with light buff dolomitic limestone and whi te/buff irregular mottled chert

Limestone , light gray, crinoidal with light buff mottled chert

Limestone , very light gray, crinoidal , massive with thin chert beds

Limestone, very light gray, dolomitic, crinoidal , irregular, interbedded with light buff dolomitic limestone and white/buff irregul ar mottled chert

prominent band w

Limestone, very light gray, fine crinoidal matrix, interbedded with gray ::!: chert ...J � telephone pole

Limestone, very light gray, glauconitic, crinoidal with large sol i tary corals; chert, very light buff

Limestone, very light buff, fine, dolomi tic, small solitary corals conman ; �rt , very light buff

Limestone, white/very light gray, massive encrinite· large and smal l

sol i tary coral s, large spiriferids .. .. " . ' . BURLINGTON LIMESTONE Limestone, light buff, fine-grained , aolomitic crinoidal with much white/ �f dolomitic mottled chert

Limestone, very light buff, encrinite with buff mottled chert

Limestone, very light buff, encrinite interbedded with fine buff dolomite and white/buff mottled chert

one, very light buff, dolomitic, encrinite with white/buff mottled �chert in lower part �one and dolomite, light buff, much irregular bedding and irreg u lar white/buff mottled chert

Dennis Hol low Local ity No. 3, Keokuk Roadcut . SE� NE� SWJ., Sec . 2, T. 3 S., R. 11 W. , Valmeyer Quadrangle, Monroe County, Illinois. FORMATION SERIE:

BURLINGTON LI M ESTONE

Limestone, light gray , fi ne-grained , hard; mi xed and interbedded with ol ive

··· and buff chert beds and irregul ar masses.

z 5 FEET w � _J � _/ - Chert , mottl ed buff, ol ive and gray in two thick beds separated by 17 inches of gray fi ne-gr�ined cherty limestone.

Limestone , light gray , fi ne-grained , hard ; mi xed and interbedded wi th ol ive and buff chert beds and irrequl ar masses.

�..,stone , gray and gray chert interbedded.

�estone , gray to buffi sh gray , fi ne-grained in thin beds interbedded wi th gray chert beds and some shal e; 7 inch chert bed at top.

FERN GLEN FORMATION

Limestone , buffi sh gray fi ne-grained wi th 4� inch greenish gray chert bed at the base.

f�-····estone , greenish gray to light buff, fi nely cri noid�l , in thin beds ; "::J interbedded with limey buffi sh gray shale. �estone , green ish gray mottl ed red, fi nely crinoidal , hard .

...../'Li;estone , red , fi ne-grai ned, crinoidal with 4 inch greeni sh gray chert bed at the top-·���--

Dennis Hol low Local ity No. 4, Creek Bed and Sidehi ll. SE� NW� SW� Sec. 2, T. 3 S. , R. 11 W. , Valmeyer Quadrangle, Monroe County, Illinois. FORMATION SERIES BURLINGTON LIMESTONE

Limestone, light buff, fi ne-grained, dolomi tic, interbedded with gray/ buff mottled chert

FERN GLEN FORMATION

Limestone, light buff, fine-grained interbedded with greeni sh gray chert

--"'"Limestone, light gray, very fine, hard z <{ Scalio . Limestone, red , argi llaceous, crinoidal , interbedded with gray and red 0::: aiiChOr". •• -.-..�...... ��--_, argi llaceous limestone w fauna > w

:?! . ...J Limestone, brown ish red , crinoidal � Limestone, brownish red, crinoidal· interbedded with calcareous red shale and argillaceous limestone

Limestone, red , very argi llaceous, crinoidal

� Limestone, light gray, crinoidal �Limestone, red, very argi llaceous, light gray in lower part -'{"°Limestone, light gray mottled reddish brown _/�hale, red , very calcareous fi e J NE ����:� �l:;;�O ii � Limesto"e• light gray, ffoe-grafoed, hard wi th thfo shal e beds W r��---�� Cl J HANNIBAL SHALE Z � Shale, light buff to greenish gray

Dennis Hollow Local ity No . 5, Bluff above creek behind houses. NW!4 SW� SW� and SW� NW� SW� Sec. 2, T. 3 S., R. 11 W. , Valmeyer Quadrangle, Monroe County, Illinois. FORMATION SERIES STE. GENEVIEVE LIMESTONE •� . . � ...... T .- . . . . 0 . . 0 . 0 Limestone , very light gray to white , fi ne-grained, weathers to brown (...... 0 n 0 0 ,_ . . . 0 . 0 0 . 0 0 (l ol ol oJoJol fo lololololo

I I l.Jo

C I I I I I I Limestone; gray, interbedded fine-grained semi �l ithographic and shaley lime stone; stromatol ites near base; gray chert ,a bundant at base '- ..... - ,... - - - - """ ,.... ,... ,_ ,,-.. ,,...... I I I I I I • 0 0 0 0 0 Limestone , light gray , mixed fi ne- to medi um-grained ool ite and fi nely crystal

o o olololol line limestone; dol omi tic al tered pseudo-ool itic in uppermost beds olo lolol•lolo z 0 • 0 0 0 olo lolo lolo lo <{ es tone, very light gray to wh ite, brecciated sub-1 ithographic and pseudo 0::: foool itic I I I I I I l w 0 0 0 > � 0 Limestone , very light gray to l'lhite, ool itic, fa intly cross-bedded, single bed w 0 0 � :E � 0 ..-�� 0 0 ·� _J " 0 0 . � jsT. LOUIS LI MEST,ONE - _J . . . � . . Limestone, very light gray to white , fi ne- to medium-grained bryozoan cal ar . 0 . 0 0 ...... enite , wi th light gray to red chert in nodul es and beds, fossiliferous 0 -' 0 . . • _J 0 D O 0 0 I o I o , o I o ·1 o 1- o I o o •l• lololo 0 D -..- 0

Limestone, light gray, fine-grai ned, very cherty; chert black on dark gray

�estone, light gray, fi ne-grai ned, single ledge 2.5 FEE T I I I I I I I I I I I I I I l Limestone, gray, fi ne- to me di um-grained with gray chert. Upper hal f pseudo-ool itic wi th upward increase in rounded coated grains I I I I I I I I

Prairie du Rocher South . St. Louis and Ste. Geneveive Limestones. One mi le south of Prairie du Rocher. Not part of regul ar land survey. Probably T. 5 S. , R. 9 W. , Randolph County, Illinois.

-- 38

Prairie du Rocher South . St . Louis and Ste . Genevieve Limestones . One mile sou�h of Prairie du Rocher . Not part of regular land survey . Probably T. 5 S., R. 9 W., Randolph County , Illinois .

The oolitic beds exposed here have been the subject of some debate in the past. They were mapped and are generally considered to be basal Ste. Genevieve but the presence of St . Louis-type lithologies overlying the best developed oolitic beds has led to the suggestion that they occur in a middle part of the St . Louis Limestone of local terminology.

The sequence here is lithologically and paleontologically similar to the upper portion of Weller and St . Clair 's Little Rock Section (Ste. Genevieve County , Missouri) ._ �oendothyranopsis has not been observed above lithologic Unit 1 and this taxon terminates at this level throughout the shelf sequences in Illinois, Missouri, Kentucky and Indiana . In lithologic Unit 1 Eoendothyranopsis rara � ·  occurs with Archaediscus , Earlandia and endothyrids .

Units 2-4 are quite similar to the bryozoan beds included in the St . Louis-Ste . Genevieve lithologic transition zones in the St . Louis, Missouri-Alton, Illinois area, characterized by Endothyra of the group apposita, Earlandia and Archaediscus .

Lithologically the base of the Ste . Genevieve is best placed at the base of Unit 5 oolitic limestone . Unit 5 contains Globoendothyra sp. and the dasyclad alga Konenokopora pruvosti/minute . The later taxon has not been observed above the St . Louis level except as relief� in basal Ste . Genevieve lithologies .

The oolitic limestone of Unit 6 is lithologically identical to the basal Ste. Genevieve in the Little Rock Section and except for the St. Louis-like lithologies the higher portion of the exposure is similar . Basal Ste. Genevieve is character ized by minute Nodosarchaediscus , with angular denticulation on the floor of the lumen (pre-Neoarchaediscus?), as part of a sparse fauna containing Brunsia , Pseudoglomospira and varfo\.ls minute endothyrids . 39

Barbeau Hollow . Ste . Genevieve Limestone and Aux Vases Sandstone . NW� SE\ SW\ Sec. 26 (projected) , T. 5 S. , R. 9 W. , Randolph Cotmty , Illinois .

At this stop , an erosional unconformity exists between the Aux Vases Sandstone and the Ste . Genevieve Limestone . On the north side of Barbeau Hollow, the Ste . Genevieve is a fine-graine d, thin-bedded, cherty limestone. This is in contrast to the south side of the Hollow, 0.15 miles (.25 km) away at Modoc Rock Shelter, where the limestone is oolitic and chert free . The Ste . Genevieve between here and Prairie du Ro cher is probably equivalent to the Fredonia Member of south-central and southeastern Illinois.

The Aux Vases Sandstone is a yellowish brown , fine-grained, well-sorted, massive , cross-bedded sandstone , which in this general vicinity attains a maximum thick ness of almost 100 feet (30 m) . Here , the Aux Vases is equivalent to the Spar Mountain Sandstone Membe r through Joppa Member of the Ste . Genevieve Limestone plus possib le equivalents of the Ro siclare Sandstone Member of the Aux Vases Sandstone of the eastern Illinois Basin area as well as the Levias Member of the Renault Limestone .

Essentially all of the Aux Vases ':; cross-bedded, and only a few ripple marks occur. Cross-bedding dip directi· ·. is are remarkably uni form in this area and suggest deposit ion by a unidirectional current flowing toward the southeast. These characters indicate that the Aux Vases is an elongate body in this area. Ove r a larger area, the character of the Aux Vases is markedly different . Cross bedding gives way to ripple marks as the dominant sedimentary structure whereas bedding becomes horizontal and thins to on ly a few feet of sandstone or locally shale . Load casts , we ll oriented groove casts and other sole marks are abundant. The se features , along with the lack of disconformity with the underlying strata, are characteristic of sheet sand bodies and are well displayed by the Aux Vases in most other cases. An outcrop showing these features well developed is present in the NW\ SW\ NW\ Sec . 3, T. 5 s. , R. 9 w. , Monroe County.

S. We ller (1913, p. 122) examined the bluffs between Prairie du Rocher an d Modoc and believed that a remnant of the Ste . Genevieve remains although he believed that the Brewerville (Aux Vases) rested unconformably in the St . Louis in much of Randolph and Monroe Counties .

This stop was also included by J. M. We ller in a Kansas Geological Society field conference guidebook in 1939 . J. M. Weller (1939 , p. 28) believed that the Ste . Genevieve was absent at this stop and that the limestone beneath the Aux Vases was the St . Louis. We ller based his belie f on three observations . The first observation was that the top of the limestone strata between here and just north of Prairie du Rocher, where the Salem was last seen, was not sufficient to carry the whole of the St . Louis below the flood plain at this point. Secondly , beds above a cross-bedded layer, which could be traced along the bluffs from Prairie du Rocher, appeared to be distinctly St. Louis in appearance . Th irdly, a dis tinct uneven contact existed between the Aux Vases and the lime stone with the Aux Vases resting on different limestone beds . The meagre confront fauna , containing "Spathognathodus" cri stulus and "§_. " campbe lli , collected from the upper 3 feet of the limestone suggests that this unit is the Ste . Genevieve . FORMATION SERIES

AUX VASES SANDSTONE

Sandstone, yel lowi sh brown , fine grained , medium to thick cross-bedded units; truncates some upper thin beds of the Ste. Genevieve Lime stone.

5 .

M z e 10 - e w t � 0 0 _J

STE. GENEVIEVE LIM ESTO NE Limestone, light gray to gray , fi ne grai ned, darker col ored chert nodules present parti cul arly near to p. A conodont sampl e from the upper 3 fe et incl udes un common to rare representati ve s of 11Spathognathodus11 cri stul us, "Spathognathodus" campbel li, Ligonodina ten ui s and Cavusgnathus unicornis.

Barbeau Hol low. NW� SE� SW� Sec . 26 ( extended ) , R. 5 S., R. 9 W. , Randol ph County, Illinois . 40

REFERENCES

Collinson , Charles, Rexroad , C. B., and Thompson , T. L., 1971, Conodont zonation of the North American Mississippian : GSA Mem. 127, p. 353-395 ; Ill. GS Reprint 1972-A.

Lane , H. R. , 1978, The Burlington Shelf (Mississippian) : north-central United States: Geologica et Palaeontologica, v. 12, p. 16�-176.

, Sandberg, C. A. , and Ziegler, W. , 1980, Taxonomy and phylogeny of some --- Lower Carboniferous conodonts and preliminary standard post-Siphonodella zonation : Geologica et Palaeontologica, v. 14 , p. 117-164.

Lineback , J. A., 1966 , Deep-water sediments adj acent to the Borden Siltstone (Mississippian) delta in southern Illinois: Ill. GS C 401, 48 p.

, 1972, Lateral gradation of the Salem and St . Louis Limestones (Middle

 Mississippian) in Illinois : Ill. GS C 474, 23 p.

Moore , R. C., 1933, Historical geology : McGraw-Hill Book Co., Inc., New York, 673 p.

Swann , D. H. , 1963, Classification of Genevievian and Chesterian (Late Mississippian) rocks of Illinois : Ill . GS RI 216, 91 p.

Weller, J. M. , et al ., 1948, Correlat ion of the Mississippian formations of North America : Geol . Soc . America Bull., v. 59, p. 91-196.

, and Sutton , A. H., 1940, Mississippian border of Eastern Interior Basin; Illinois Geol. Survey Rept . Inv . 62, p. 765-858 .

We ller, Stuart , 1914 , Mississippian Brachiopods of the Mississippi Valley Basin ; Ill. GS Mon . 1, pl. 1, 508 p.

Workman , L. E., and Gillette, Tracey, 1956, Subsurface stratigraphy of the Kinder hook Series in Illinois : Ill. GS RI 189, 46 p. 41

THE STAATOTYPE OF THE CHESTERIAN SERIES

In 1860 Worthen first proposed the name Chester as an alternative name for the "Upper Archimedes limestone ," a succession of strata between the "Fe rruginous sandstone " (Aux Vases Sandstone ) and the "Coal Me asures" (Pennsylvanian) which crop out near Ch ester, Illinois . Kaskaskia, proposed for this same sequence by Jame s Hall (1957) , was ove rlooked. Englemann (1863) , Worthen 's assistant, included the "Fe rruginous sandstone" in the base of the "Che ster limestone ." Wo rthen (1866, p. 77) indicated that the " group comprises three or more beds limes tone , with intercalated beds of arenaceous and argillaceous shales and sandstones , the whole attaining a maximum thickness, in Ran dolph County , of at least six hundred feet ." A maximum thickness of over 1400 feet is present in southern Illinois near the southwe stern edge of the Illinois Basin .

Mo st of the formations today re fe rred to the Chesterian Series can be identified in an outcrop within a few miles of the town . Strata representing the few re maining formations can be found within a few tens of miles from Chester with the exception of the Grove Church Shale wh ich occurs some 50 miles away in Johnson County , Illinois. Although most of the Chesterian section repre sented is in the Che ster area, the type sections of formations comprising the standard column lie in a semicircular belt that extends around the southern half of the Illinois Basin.

As proposed by Worthen (1860, 1866) , the Chesterian forms a natural series of strata between the dominantly lime stone units of the present Valmeyeran Series below and the elastic un its of the Pennsylvanian System above . This concept remained essentially unchanged for many years . Ulrich (1905 , 1911 , 1917, 1922) strongly advocated the placement of the lower Chesterian boundary at the St . Louis Ste . Genevieve boundary . He indicated that a regional uncon formity occurred between the se two formations and that fauna of the Ste . Genevieve was more closely allied with that of the Ch esterian formations above than with that of the St. Louis below . We ller (1907 , 1913 , 1920) continued to place the lower boundary between the ranges of Platycrinit�E_ p� �icil�- and Talarocrinus (between the present Levias and Shetlerville Members of the Renault). In areas where these fossils could not be recognized, the boundary was placed at the base of the Aux Vases . This boundary received little scrutiny until Swann and Atherton 's (1948) subsurface correlation of the lowe r Chester. Their work pointed out that , although the upper part of the Aux Vases was a lateral facies equivalent of the Levias and perhaps part of the Shetlerville Members , the lower part was a facies of the Ste . Genevieve . There fore , the basal Cheste rian boundary was much highe r to the east than it was in the we st. Swann (1963) corrected much of this problem by placing the [\.ux Vases in the Valmeyeran Series. After that the boundary was traced westward along the Levias-Shetlerville contact until it could not be recognized and then continued along the top of the Aux Vases Sandstone. As it stands this may place a small part of the Aux Va ses of southwe stern Illinois into the Valmeyeran which technically may be of Che ste rian age . 42

The upper boundary of th e Chesterian has never been in que stion until quite recently, and it was generally known that there was a small time gap between the uppermost type Chesterian (Grove Church Shale) and the base of the Pennsylvanian (type Morrowan). Strata spanning this time gap is represented by the Rh achistognathus mu ricatus Zone in southern Nevada , and may be represented in north-central Arkansas and southern Oklahoma (Lane and Straka, 1974, p. 22) . New information (Rexroad and Me rrill, 1979; Merrill and Re xroad, 1981) indicates this time gap may be very small or non-existent in a localized area of southern Illinois.

Three stages have been proposed by Swann (1963) for the Chesterian . The Gaspe:tian is named for the Gasper Limestone of Kentucky and includes, at its re ference section , rocks from the base of the Shetlerville Member of the Renault Limestone up to the top of the Beech Creek Limestone . Important fossils in this stage include Talarocrinus , Amplexus geniculatus , and Pentremites godoni. The Hornbergian stage is derived 'f:C"on;H�erg in PopeCcnmty , Illinois and cove�s strata from the top of the Beech Creek to the top of the Glen Dean . Prism-9125?_3'..:� ?erratula and several species of ?terotocrinus are the characteristic fossils. The Elviran stage is named for Elvira Township , Johnson County, Illinois . It includes the remainder of the Che sterian format ions above the top of the Glen Dean . Repre sentative fo ssils are !'en!_.�ernites fohsi, Pterotocrinus m<:_narde�si�, Com.12.osita _::;_1:1 bq�drata and Eumet!"ia costata.

Six conodont zones proposed by Collinson et al . (1971) are more important for international correlation of Che sterian strata than for local correlations .

The stratigraphy of the Chesterian will not be discussed here but excellent de scriptions are given in Swann (1963) and Willman et al . (1975) . A stratigraphic column is shown in figure following page 33. Local stratigraphic information is given in the stop descriptions. FORMATION SERIES

RENAU LT LIM ESTON E

Shale, red , purple, green , soft with thin sandstone stringers

- ..bi · · '.·, z Limestone, gray, sandy, single bed <(- 0:: LIJ Limestone, gray, coarse-grained, fossiliferous, upper part sandy with I- interbedded greenish gray shale CJ) w :c 0 Limestone, greenish gray interbedded with greenish gray sandy shale

Shale, greenish gray, calcareous with limestone lenses 10 FEET Limestone, gray, sandy, fossiliferous; shale, greenish ·gray

...... · � ·:. ·. :.·. � · .·. AUX VASES SANDSTONE . . · . · ·. " : ' : � �; . . · ...... � .· . · . .· Sandstone, gray, in beds, fine-to medium-grained with some . : . · . . . · 611 shale pebbles _J · · cross-bedded . Numerous bori ngs ·. · · .·.· : . scolithus <( .�. · : . . . : . . . . · . . ·�· . · :·· > · · . · : · . · . . . . . ·. :: ...... -:.:� : ·. : �. ' : : .. .. . : . : - : : . · . . ·� . . Sandstone.a fine, cross-bedded .

Type Renault (Dry Fork East) . Outcrop on east bank and in stream bed of lowest tributary gulley to the south of Dry Fork Creek , E� SW� Sec . 23, T. 4 S., R. 9 W., ·Ames Ouadranqle, Monroe County, Illinois. 43 r J itJ I ·':;:;>f""c1 J( Type Renault (Dry Fork East) . Outcrop on east bank and in stream bed f o lowest tributary gulley to the south of Dry Fork Creek , E� SW� Sec. 23, T. 4 s. , R. 9 W. , Ames 7� ' Quad. , Monroe County, Illinois.

The lower half of the section is well exposed in the east bank of the gulley about 300 yards south of the gulley' s juncture with Dry Fork. The remainder of the section is intermittently exposed in the stream bed. The cherty sandstone . of the Yankeetown can be found in the cultivated field to the east of the gulley

· in the SE� SW� of Sec. 23. The Levias Member has not been recognized at this local�ty (Platycrinites pencilillus has not been found) . The sandstone at the base of the exposed section generally has been placed with the Renault (S. Weller, 1913) and this unit may _be �quivalent to the Levias and perhaps even to part of the Shetlerville Member. In S. We ller 's (1913, p. 122) de scription .of the Renault, he indi cated that "the formation undoubtedly includes some portion of the 'lower sandstone of the Chester group ' (present Aux. Vases) of Worthen ." The flaggy , Scolithus-burrowed, sandstone beds below the more cal careous beds were included in the Renault by We ller because an unconformity , recognized through argillaceous beds , limestone lenses, or a limestone conglom erate separated the so-called Renault sandstone from the Aux Vases . Where the se beds are not present- and the unconformity is not recognized, al l the sand is placed in the Aux Vases. There fore , even in a localized area, the top of the Aux Vases may be stepped up or down . The extent of the unconfo rmity within and outside of Monroe County is not known , although a similar occurrence is pre sent in the Renault-Aux Vases . sequence near St . Marys , Missouri . We tentatively propose that the two sandstones be placed together under the name Aux Vase s, although additional subsurface work may indicate an alternative solution . The sandstone at the base of this section is very similar in lithology to the type Aux Va ses although it has low angle cross-beds , planar bedding and ripple marks which are not as common in the more massive , high angle cross beds of the more typical Aux Vases. Potter (1963, p. 69) has included an 8-10 foot unit of thin planar-bedded sandstone (sheet sands) at the top of the more massive sand stones (belt sands) of the Aux Vases. Potter indicated the "transition from belt to sheet sand body occurs within approximately 2000 feet in the north-central portion of T. 5 S. , R. 9 W. " This area is just a few miles from the type Renault . If the se sandstone units are combined, it will preserve the lithologic integrity of both the Aux Va ses Sandstone and the more calcareous Re nault Limestone .

In times past, unconformities or distinct lithologic breaks were used to differ entiate formations more than internal lithologic consistency . Unfortunately, for the Chesterian , it is difficult to preserve litho logic consistency at least around the basin . During the period of the petroleum boom , beginning in 1937 in the Illinois Basin, oil field terminology re sulted in further re striction of the sandstone units wh ile the intervening shales and argillaceous sandstones commonly were placed with the adj oining limestone unit . In more recent years , the oppo site situation is occurring as the stratigraphe rs have attempted to keep the limestone units pure and have placed the intervening shales , even fossiliferous calcareous shales , with the adjoining sandstone unit.

J. M. We ller (in S. We ller and J. M. We ller, 1939 , p. 10) suggested that the entire Aux Vases should be considered a basal member of the Re nault that occupied channels cut into underlying beds . 44

Stuart Weller (July 25, 1912 , unpublished notes) lists the presence of the following fossils from this locality (Weller fossil locality W5 78, NE\ SW\ Sec . 23, T. 4 S. , R. 9 W) : Spirifer increbescens , Composita, Pentremites , Zaphrentis , bryozoans ' (no Archimedes) , and echinoderm stems . The fossils were collected from a 15-foot unit of calcareous shale and argillaceous limestone , the base of wh ich is 2-3 feet above the flaggy sandstone beds .

All of the usual Chesterian conodonts have been found in the type section including the form species Cavusgnathus unicornis, "Spathognathodus" cristulus , ".§_. " spiculus , ".§_. " campbelli, Ligonodina tenuis , Magnilaterella robusta, and Neoprioniodus scitulus . Abundances vary from common to uncommon . Rexroad (1957, fig. 5, p. 11) collected samples primari ly from the greenish gray arenaceous and calcareous shales. Norby (1976) partially recollected this section and concentrated on the more calcareous shales and limestone s. The lime stones, wh ich are very argillaceous and arenaceous , did not exhibit any significant conodont fauna! or abundance di fference from the more argillaceous beds . ;, .

. FORMATION SERIES f-! YA NKEETOWN SANDSTONE (/') Sandstone, yellowi sh brown , fine-to very-fine grained, thinly laminated, w :c 1.. Ulltorte d in places, weathers into cherty blocks with lamination streak . .A· . . · A·· ·/); . : . of 0 . . . . .' :t:i.· . A.:�: ·. . . . . �------RENAULT, LIM ESTON E g-- - Shale, greenish to dark red , fi ssile, with thin limestone stringers, basal / and radial plates of Talarocrinus common on limestone surfac�s , z I I I I I _,. <( I I I I I I I I Limestone, light gray, crinoidal , fossiliferous, massive to thin bedded ; er: interbedded with green calcareous fissile shale; contains Talarocrinus I I I I I I I plates w I I I I I I I I I > I I I I I I I w I [ :?! I I I I I I I 5 FEET _. ( I I I I I I I f I I I I I I � I I I I I I I on sh n i eT a n d . · · ·. · · · J �� . �. . · ·. . ".:" :_.:d/ ...... :;.·. ·. ::- .·. · . . � �� :i�; ;! �: �; . · . · .. . · . ....· . · . J ...... · .. . . . : : ... : : : : . :,;�I

Type St. Marys. Roadcut on U.S. Highway 61 , 0.6 mi le northwest of bri dge in St. Marys and 1.7 mi les southeast of bri dge over Sal ine Creek, SE� NW� Sec. 29 (extended) T. 37 N. , R. 10 E. , Kaskaskia 7�' Quad� , Ste . Genevieve County, Missouri . 45 <;fc>f St. Marys . Roadcut on U. S. Highway 61, 0.6 mile northwe st of bridge in St . Marys and 1. 7 miles southeast of bridge over Saline Creek , SE\ NW\ sec. 29 (extended) T. 37 N. , R. 10 E. , Kaskaskia 7�' Quad. , Ste . Genevieve County, Missouri.

Weller and St . Clair (1928, p. 233) de scribed a quarry section which is just adj acent to this roadcut. The exposure in the quarry is nearly overgrown now. Weller and St . Clair did -not find any sandstone exposed inunediately below the lime stone but did find sandstone close by in the adj acent creek bed. They reported that sandstone °ledges exhibit Scolithus burrows similar to those present in the sandstone at the base of the type Renault section . We ller and st . Clair (1928, p. 233) believed this sandstone to be a channel- fill deposit on an eroded .Aux Vases surface and hence the initial pulse sigiialing Renault deposition. Addi tional evidence of an unconformity was provided by a.short ro adside exposure about 0.5 mile north .of this roadcut (Weller: and St. Clair, 1928, p. 232) . A "lime stone conglomerate was fomid with approximately 2 feet of clay and sandstone below it . Weller and St . Clair considered this conglomerate to be at the base of the Renault . Aux Vases Sandstone was found a few yards away . Shumard (1855) had observe d a. similar conglomerate one mile north of St. Marys .

This section was previously included as Stop 41B in a field trip conducted by J. M. We ller (1939, p. 81) . Sandstone beds , expo-sed below the -l.ime stone beds of the Renault , were included by J. M. Weller in the Aux Vases Sandstone . Additional reasons for placing similar sandstones in the Aux Vases were discussed by swann (1963 , p. 31, 32) who indicated that the sandstones at this stratigraphic level have been variously assigned to the- �nault or the Aux Vases.

Rexroad (1957 , p. 22) reported a very mea�re conodont fauna consisting of Ligonodina tenuis, Neoprioniodus scitulus and Hindeolla �· Semicircular basal plates and ·quadangular radial plates of Talarocrinus are quite common throughout most of the formation wh ich suggests that the Renault here is composed entirely of the Shetler ville Member. .-

FORMATION SERIES

AUX VA SES SANDSTONE ? co·vered interval + 28 feet to limestone beds of the Renault. Ul rich (1922 , p. 828) indicates-that this is a massive sandstone which he cal led the upper member of the Aux Vases . . · stone, light brown fine-grai ned. z � tructures. Other lithologies include subli thographic, brecciated w .. ·::·. l�!l : .�:'.·. · . · . ·.::. . ppeari ng limestone with sponge? spicules ; brownish gray to purple � � · . . ;: tained, medi um-grained ool ite with uncoated intraclasts ; and light _J :-· }Jrown ish gray to purple, medi um- to coarse-grained calcarenite with ...� � : �·/\.'�:�>: /:: .. � ·� �:.).:):·:;:.:.�.:: chinoderm fragments. -- . . � covered · , . �st�ne ,, light brown , fi ne-grained. .__._...... _....._,..._....._....-..____. __._ __

Covered interval + 8 feet to limestone beds of the Ste . Genevieve. According to Ul rich (1922 , p. 828) this interval covers the lower member of [ 2 feet the Aux Vases whi ch is more cal careous and thinner bedded than the upper member. The top of the covered interval is approximately at the level of the old lane on the west side of the railroad tracks .

Type Aux Vases Sandstone. Limestone lens wi thi n the Aux Vases Sandstone. Exposure along old lane on west side of St. Louis-San Franci sco Rai lway tracks near base of bl uffs , approximately 2200 feet southeast of U.S. . Highway 61 bridge over Aux Vases Ri ver, and approximately 1400 feet south east of juncture of ol d land and U.S. Highway 61, NW!ii NE!ii Sec. 13 (extended) T. 37 N. , R. 9 E; , Kaskaskia 7� ' Quad. , Ste . Genevieve County , Mi ssouri . · ) .. ·· 14 46 ,/·-f' j _'.;;> . 't") . Type Aux Vases Sandstone. Limestone lens within the Aux Vases

Sandstone. · Exposure along old lane on west side of St. Louis-San Francisco Railway tracks near base of bluffs , approximately 2200 feet southeast of u. s. Highway 61 bridge over Aux Vases River and approximately 1400 feet southeast- of juncture of old lane -and �u . s. Highway 61, NW� NE� Sec. 13 - (extended) , T. 37 N. , R. 9 E. , Kaskaskia 7� Quad. , Ste . Genevieve County, Missouri .

Ulrich (1922� p. 828) ·reported a marine unit within. the Aux Vases at this app roximate location . He described an 8-foot unit. of calcareous red and green shales that contain a layer of suboolitid limestone sandwiched between two sandsto:qe units . Ulrich's exact exposure was not discovered, however, an exposure _of red and green shales with a thin limestone layer, is visible at present under two uprooted trees, approximately 150 yards north of this stop on the. _e.ast side of the old lane.

The limestone surfaces exhibit ab'µndant fossil remains, including rare occurrences_of columnals of Platycrinites penicillus. Ulrich (1922 , p. 828) recovered a. columnal and basal ring plates of this crinoid along with 40 other species including Pugnoides . ottumwa. To Ulrii:h, this was a mo st important section , inasmuch as he regarded the bryozoan fauna to represent varieties of later-appearing C4e sterian species which he had not observed in any Ste . Genevieve fauna or in the "Upper Ohara beds" (= present Shetlerville Member and po ssibly up to and includip.g the Downeys Bluff) . For these reasons, Ulrich believed that Platycrinites penicillus and Pugnoides ottumwa ranged higher than the Ste. Genevieve , one bf many points of dispute that he had with . Stuart We ller.. Ulrich believed that Weller would have called the marly beds "Lower Oh ara" (generally .= present Levias Member) and the sandstone beneath it Rosiclare because We ller believed that Platycrinites penicillus and Pugnoides ottumwa were never found above the base of the "Upper Ohara ." It is not known if Weller ever saw this exposure , for no comment is made concerning it in his later publicat.ions.

At the present time , the time�stratigraphic position of this limestone unit is not known . The unit may be equivalent to part of the Karnak , Joppa or Levias . Swann (1963 , p. 47, fig. 16) placed it near the middle of the Aux Vases at approximately the level of the Rosiclare . The lithology is most similar to the Levias Member of the Renault in Hardin County , Illinois or to the . Joppa Membe r of the Ste . Genevieve in other areas . If equivalent to the Levias , this would suggest that the saµdstone above the limestone bed is equivalent to the Popcorn Sandstone Bed wh ile the sandstone below could represent any part of the Aux Vases. If the limestone bed is Karnak or Joppa, the sandstone below it could be Spar Mountain . Additional subsurface information may answer that question but correlations are difficult at this horizon in southwe stern Illinois . FORMATION SERIES 10 STE. GENEVIEVE LI M ESTONE 'I

Sandstone , light yel lowish brown with scattered smal l brown iron spots , th in 10 shaly partings present ; grades into unit below. This unit is referred to as the . . Spar Mountai n Member • Milters . . ..

Feet

0 (Li mes tone , light olive gray to light dusky ye 11 ow , fine to medi um grai ned , very _J �renaceous and glauconitic at top , nodul ar-like beds at bottom; echinoderm fragments , some replaced by reddi sh col ored chert ; fo ssils common , especi al ly productid brachi opods . z <( 0:: Limestone , yel lowish gray to light olive gray , mottl ed in places , medi um grained to subl ithographi c; glauconitic, slight crossbeds di p southwest, fossils present. w > w � imestone, light yel low.i sh gray to ol ive gray , subl i thographic to medi um [L · _J _J grained, nodular weatheri ng . <( ....llimestone , light yel lowish gray , fi ne grai ned to sublithographic. > Limestone , light yel lowish gray , sublithographic to fine grained , nodular weathering, some fossils.

Limes tone , light yel lowi sh gray , medi um grai ned· to biocalcareni tic; fai nt crossbeds dip south; banded chert at top , orange-red, tan to brownish black.

Limestone , light yel lowish gray , subl i thographic at base, becoming fi ne to medi um grai ned and biocarenitic a few inches above base, partly oo litic; some south-dipping crossbeds or chert nodul es ; thin shaly partings at top .. Contact wi th St. Louis incl ined south and truncates some St. Loui s beds ; unit pinches

out at north end of bluff • .JS T. LOUIS 'LIMESTO NE Limestone, light to medi um gray , lithographic, green shale parti ngs between beds ; no fossils observed .

Ste . Genevieve South . Sec . (extended), T. Ste . NW� NW� NE� 34 38 N., R. 9 E., �!1: Genevieve Quadrangl e, Ste . Genevieve County, Mi ssouri . I / l -� 47 010 v:1'-') Ste . Genevieve South . NW\ NW\ NE\ Sec. 34 (extended) , T. 38 N. , R. 9 E. , Ste . Genevieve 7� ' Quad. , Ste . Genevieve County , Missouri.

Shumard (1859) did not define a type section when he designated a second Archime des limestone beneath the ferruginous sandstone as the "Ste . Genevieve limestone ." All of ·the outcrops which he discussed lie south of Ste . Genevieve. Therefore , this section, which is the closest and o�e of the best exposed outcrops south of town , is considered the type section although Weller and St. Clair (1928, p. 220) did describe an important section 1.4 miles south of _this outcrop . This latter outcrop is no longer well exposed, particularly the Platycrinites penicillus-containing limestone above the sandstone unit. Short (1962, p. 1918) also selected this outcrop as the principal type section for the Ste . Genevieve south of town. This section, as recognized by Shumard an� later workers, rests unconformably on the St . Louis Limestone . Short (1�62) has raised some . doubts on whether the limestone below the disconformity is truly St . Louis as no fossils had been found in these rocks. Weller and St . Clair (1928) placed the se rocks in the St. Louis based on the presence of the unconformity and the sublithographic texture of the lime stone below the unconformity. Short (1962 ) presented some evidence on insoluable re sidues an� heavy minerals which only suggested that the limestone above and below the unconformity are more closely related than expected. A recent conodont Srut\Ple from the limestone below the unconformity has yielded a meagre and undiagnostic fauna consisting of diminuative repre sentatives of Cavusgnathus. Therefore , the St . Louis age of this lowest limestone is questionably retained until more data can be collected.

Short (1962 ) has correlated the . dozen or more outcrop sections of the Ste. Genevieve in the type area with a fai� degree of confidence . He has used � a ma�ker bed and insoluable residues which indicate that the lowe st two units of the Ste. Genevieve above the unconformity correlate with the upper third of the Ste . Genevieve Limestone in the Little Rock quarry north of · town . Beds equivalent to the upper two-thirds of this section have been eroded away at Little Rock quarry .

Twelve conodont sampl,es were taken here in 1972 which yielded a moderately abundant fauna. Cavusgnathus unicornis and "Ligonodina" tenuis with associated apparatus elements are common to abundant in most samples. "Spathognathodus" cristulus, ".§._. " spiculus, and ".§._. " campbelli appear in several samples . An interesting and probably useful occurrence is the presence of two specimens of "Gnathodus " homopun ctatus in sample 4 (ca. 12 feet above unconformity) and the possibility of another two (very small) specimens in sample 5 (about 15 feet above unconformity) .

,� 49

REFERENCES

Collinson , Charles, C. B. Rexroad , and T. L. Thompson, 1971, Conodont zonation of the North American Mississippian : Geo1. Soc . America Mem. 127, : p. 353-395; Ill. Geol. Survey Reprint 1972-A.

Engelmann , Henry , 1863 , On the Lower Carboniferous System as deve loped in southern Illinois : St. Louis Acad. Sci. Trans �, v. 2, pt . 1, p. 188-190.

Hall , "James ,· 1857, Observations · upon_ the Carboniferous .limestones of the Mississippi Valley (abs.): Am. Jour . Sci. , v. 23, p. 187-203.

Lane , .H:. R. , and J. J. Straka I�, 1974, Late Mississippian �d early Pennsylvanian donodont Arkansas and Okl ahoma :: Geol. Soc. America Sp . Paper 152 , 144 p.

. . Merrill, G. K. , and c. B. Rexroad, 1981, Conodonts from the Middle Carboniferous of southern Illinois and the base of the Pennsylvanian System (abs. ): Geol . Soc. America, Ab stracts with Programs , v. 13 , p. 309.

Norby , R. D. , 1:976 , Conodont apparatuses from Chesterian (Mississipp ian) Strata of Montana and Illinois : Univ. Illinois at Urbana-Champaign , unpublished Ph .D. dissertation ,. 295 p. , 21 pl.

Potter, P. E. , 1963, Late Paleozoic sandstones of the Illinois Basin : Ill. Geol . Survey Rept . Inv. 217 ,· 92 p.

Rexroad , C. B. , 1957, Conodonts from the Chester Series in the type area of southwe stern Illinois : Ill. Geol . Survey Rept . Inv. 199, 43 p.

,Rexro ad, c. B. , and G. K. Mert'ill7 1979 , Conodont biostrat igraphy and- the Mississippian-Pennsylvanian boundary in southern Illinois (abs. ): Ninth

Int . Cong. Carb� · Strat. Geol ., Abstracts of Papers , p. 179-180 .

Shumard , B. F. , 1855, Description pf a geological section , on the Mississippi River, from St . Louis to Commerce , p. 137-238 in G. c. Swallow , the first and second annual reports , Geol . Survey of Missouri .

Swann , D. H. , 1963, Classification of Genevievian and Che sterian (Late Missis sippian) ro cks of Illinois : Ill . Geol . Survey Rept . Inv. 216, 91 p.

Swann , D. H. , and Elwood Atherton , 1948 , Subsurface correlations of lower Che ster strata of th e Eastern Interior Basin , in Symposium on problems of Mississipp ian stratigraphy and correlation : Jour. Geology, v. 56, p. 269-287; Ill . Geol . Survey Rept . Inv. 135.

Ulrich , E. o. , 1905 , Geology and general relations , part 1, p. 7-105 , in E. o. Ulrich and W. s. T. Smith , Lead, zinc , and fluorspar deposits of western Kentucky : U. S. Geological Survey Prof. Pape r 36 , 218 p.

Ulrich, E. O. , 1911, Revision of the Paleozoic systems : Geol . Soc. Ame rica Bull ., V· 22 , p. 261-680. 50

Ulrich, E. o. , 1917 , The formations of the Chester Series in western Kentucky and their correlates elsewhere , in Mississippian formations of western Kentucky : Kentucky Geol. Survey�(ser. 5, v. 1, pt . 2) .

Ulrich , E. o. , 1922 , Some new fact� bearing: on correlation of Che ster fonnations : Geol. Soc. America Bull. , v. 33, p. 805-852 .

We ller, J. M. , 19 39, Mississippian System: Kans. Geol . Soc . Guidebook , 13th Ann. Field Conf. , southwestern Illinois and southeastern Missouri , p. 131-137.

· -Weller Stuart , 1907, Geological map of Illinois (2nd Ed.) : Ill. Geol . Survey . Bull . 6, 34 p.

Weller, Stuart , 1913 , Stratigraphy of the Chester Group in southwestern Illinois : Ill. Acad. Sci. Trans. , v� 6, p. 1!8-129.

Weller, Stuart , 1920, Che ster Series in Illinoi� : Jour. Ge�logy1 v. 28, p� 281-303, - 395-416 .

We ller, Stuart , and Stuart St . Clair, 1928, Geology of Ste . Genevieve County , Missouri : Mo . Bur. Geol. and Mines, v. 22, 352 p.

Weller, Stuart , and J. M. Weller, 1939, .· Preliminary geological map s of the- pre Pennsylvanian formations in part of southwestern Illinois : Ill� .. Geol . S rvey Rept . Inv. 59, 15 p. � \

Worthen, A. H. , 1860, Remarks on the discovery of, a terrestrial flora in the Mountain Limestone of Illinois (abs.) : AAAS Proc. , v. 13 , 312"-313 .

:Worthen , A. H. , 1866, Geology : Geol. Survey Illinois , v. 1, 504 p •

.short , N. M. , 1962 , Ste . Genevieve (Mississippian) Formation at its type locality in Missouri : Am. Assoc. Petroleum Geologists Bull. , v. 46 , p. 1912-1934 . t==' -==No. rth :: "lo mi: = IOkm. I -

'• 51

THE KINDERHOOKIAN SERIES

The Kinderhookian Series (Meek and Worthen , 1861b , p. 288 ; Collinson , 1961, p. 102) is named for the village of Kinderhook , northwe stern Pike County , where the type section cons ists of exposures in the Mississippi River bluffs . There the Kinderhookian strata overlie the Devonian Saverton Shale whereas the Mccraney Limestone underlies the Valmeyeran Burlington Lime stone at the top' of the section. The Prospect Hill sandstone wh ich overlies the Mccraney is exposed a few miles to the north . The Horton Creek Formation which is the oldest Kinderhookian unit is exposed a few miles to the south . The Chouteau Lime stone which is essentially a time equivalent of the Mccraney and Prospect Hill. occurs in the bluffs 50 miles to the south . All can be correlated by bed tra.cing . The Kinderhookian extends throughout most of we stern , central , and southern Illinois ; northeastern , central and southwe stern Missouri; and southeastern and north central Iowa � It is best exposed along the Mississippi, Illinois and Meramec River Vallies . The series reaches a maximum of 167 feet along the Mississippi Valley between Kinderhook and Burlington , Iowa whe re the Starr 's Cave , Prospect Hill and .Mccraney Formations are present . The series thins southward .to 50 feet north of Kinderhook and then thick ens to more than 150 feet thick in Calhoun County . The Kinderhookian thins eastward int o the Illino is Bas in as we ll as southwes tward onto the Ozark Dome . Westward aci:-oss northern Missouri, the series maintains a thickness of about 75 feet.

As 0 originally defined , the Kinderhook Group included all the strata between the bl.fl.ck shale (Grassy Creek) and the Burlington Limestone , strata previously corre lated with the Devonian Chemung Group of New York . Later, the black shale was also included in the Kinderhook Group and assigned· to the Mississippian . After the Kinderhookian became a series , the position of the �ississippian-Devonian boundary became controversial (Stainbrook , 1935 ; Weller , 1939) . Studies of the conodont faunas resulted in a redefinition of the Kinderhookian Series to include only those strata overlying the Louisiana Lime stone and underlying the Meppen Lime stone or t!1e Burlington Limestone where the Me ppen is ab sent (Collinson , 1961) . As thus defined , the Kinderhookian Series includes the upper part of the New Albany Group , the widespread Chouteau Limestone , and , in a small area in western Illinois , the No�th Hill Group .

The. Kinderhookian is generally conformable with the Upper Devonian Series (below) and the Valmeyeran Series (above ), bu.t in western Illinois both contacts are marked by local unconformities that resulted from minor uplifts on the flanks of the Ozarks .

The top of the Kinderhookian is marked by a regional unconformityc that resulted in removal of two-thirds of the Hannibal in relatively restricted areas of wester� Illinois and northeastern Missouri but elsewhere there is little if any time gap . The Hannibal , Chouteau, Mccraney , Prospect Hill and Starr 's·Cave all cap the s�ries in places . The Hannibal which has the greatest distribution and thickness of any Kinderhookian format ion was mainly derived from a source northeast of Illinois with small additions from the northwest and from the Ozark region on the southwest . 52

Overlying tJ:1e Hannibal , the Mccraney is 10� feet (3.2 m) thick . It is typically deve loped .. and is virtually nonfossiliferous except for a fairly abundant arenaceous foraminfera fauna. The formation consists of gray to brownish-gray .lithographic to sublithographic limestone interbedded with buff dolomite . The formation intergrades somewhat with the underlying siltstone as shown by a wavy-bedded silty zone at the base . Although apparently identical in .lithology to the Louisiana, the Mccraney is -�easurably siltier. _Insoluble residues from the McCraney range from 5 to 25 percent by weight and average 11 percent. Re sidues from the

.. Louisiana �ve rage only 3 percent and range from a trace to 5 percent •

Northward from this outcrop, the Mccraney· increases in thickness to a maximum of

•. more than 40 feet (12 m) in .the vicinity of Fort Madi�on , Iowa . Three miles (4 .9 km) north of here# the Mccraney is overlain by 3 feet (4.s m) of siltstone referable to the Prospect Hill Formation , which is indi stingliishable lithologically from the siltstone of the Hannibal.

The pure , coarsely crinoidal beds of the lower part of the Burlington Limestone overlie the McCraney unconformably and are relatively accessible here. , � � � ' � � "- ::::s � Q) § � � � � � � § t:: � Q) � G � .... � § � Cb � � � "- � f: § § � � G � § � G § � G § -c:: � � � � � � ::::: Q) -� 3t: � � � � � � � � � � Qj Qj �

/ / HANNIBAL / --- I - . I/ -- I .- _..-r - -- --! -- -- I I

SAVERTON

SWEETLAND CREEK ····. . . .

Cross section of late Devoni an-Kinderhookian rocks in the east .c:: � � � � � .c:: � 't: :::i "'� ' § � ::::::...... 1: � :::s =t (3 � � ...... Cl) � � � 1: ...... � � �� ...... -� � :::i :::i � § t) � § � Cl) � �� a "fi "'�. · � � � ' "§ -� ...... � :-..;. § § � � cs � ""S � �· Q;: � � � Q;: :t � <.!)

50 HANNIBAL feet

bl uff of the Mississippi River Val ley between Quincy and Hamburg , Ill ino is. SAMPLE FO RMATION SERIES STATISTICAL SAMPLING DETAIL 29 BURLINGTON- Limestone, buff to white, very coarsely crinoidal. Single white ta buff chert bed. Silty dolomite bed at base. 28

26 25 l HANNIBAL- Siltstone, buff to gray, calcareous 24 in upper part. Shale, gray to greenish gray, silty, poorly laminated. 23

22 A 21 z 0 20 VERTICAL SCALE fT1 20 ::u 19 I 0 18 0 A 10 17 l> z 16 0

/GLEN PA RK"- Limestone, buff, dolomitic, silty, 13 fossiliferous.

12 SAVERTON · - Shale, greenish gray, soft with I siltstone nodule bed and silty limestone beds c II showing flow s1ructures. "U -u 10 fT1 ::u

9 See sampling detail for intervals of 0 ] -- statistical samples taken here. fT1 8 < 0 7 z

6 l> z - - --- 5 4 GRASSY CR EEK 3 _/ - Sho1e, dork brown . to black, 2 very fissile, numerous Tosmaniles.

Atl as South. SE� Sec. S. , 4 W. , Pike County, 35, T. 6 R. 53 . ; I k> /':-f{)f �· Atlas South. SE� Sec. 35, T. 6 s. , R. 4 w. , Pike County , Illinois

This exposure which extends along the bluff for mi les is of special importance in that it probably represents the most complete section available in the Mississippi Valley for' the study of faunas and deposition in the vicinity of the Devonian-Carboniferous boundary . Conodonts are conunon . The late Devonian Bispathod�s aculeatus-Zone , the latest Devonian prae sulcata-Zone , the earliest Mississippian sulcata-Zone and the succeeding duplicata-Zone are all well developed. All or much of the Bispathodus costatus-Zone appe ars to be gone from the upper Saverton.

Even though the Louisiana Limestone is entirely missing and the oolitic�Jimtown • Branch channel fill is only a few miles away , the only carbonate in the section is a few feet of dolomi tic0 ·Horton Creek limestone that carries a brachiopod fauna along with the sulcata-Zone conodont fauna .

Fifteen feet (4.5 m) below� the Horton Creek ledge a well developed middle costatus Zone fauna can be collected along with a spore assemblage that includes Hyrnenozonotriletes lepidophytus along with 18 other species. Acritarchs also are abundant .

The Saverton Shale-Grassy Creek Shale contact is exposed at the bottom of the hill. Because of slump from above the age of the contact has never been satis factorily determined. It was from this section that Scott and Collinson (1959, 1960) assembled their large collection of Palmatolepis glabra which they subj ected to intraspeci£ic variation analysis.

The bluff. is capped by several conical' mounds of loess that are typical of the bluffs in thi s area. The mounds served as lookout points for Indians in the area and commonly are burial sites . In the past , many flint scrapers , hunting points , and flint chips have been collected from the surfaces of such mounds . From the bluff , one has an excellent view of Clinton Springs Hill south of Louisiana , Missouri , as well as Buffalo Creek and Noix Creek valleys .

'• SAMPLE FORMATION SERIES

BURLINGTON - Limestone, light buff, massive, coarsely crinoidol; Chert, light buff fa while, scattered. · < Dolomite, buff, fine-grained, crinoidal. l> r Limestone, very light gray, coarsely crinaidal. Limestone, light buff, dolomitic, crinoidal. ., � 28 Limeslone , very light gray lo lighl buff, crinoidal.

� MCCRANEY- Limestone, gray la brownish gray, � 27 lithographic lo sublilhographic, weathers very light ""C gray, irregularly interbedded wilh dolomite, buff, silly, A g> numerous calcite vugs. c:: . -� ..... ::z: ;:,. HANNIBAL - Siltstone, buff, massive, calcareous 0 and i;lig�ty vermicular in uppermost few feel. lnfer rri grndes with overlying limestone, Shely beds form ::0 reentranfs in outcrop that may in some places I contain silty shale. 0 0 A l> Siltstone, very massive, blue·gray to buff, upper ::z: 3 inches marked by blue-gray zone. Lowermost 3 feet especially vermicular, pyrific and fossiliferous. Casts of b"rochiopods and pelecypads.

-· ·-- --- ·------· ·· ---··- - ...... - . -- -· ... SAVERTON - Siltstone, blue-gray lo buff, argillaceous, :: : .-: :: :. = :.=: .. -:: :-. ----· : .:.::.: indistinctly alternating with silly shale beds. Forms lower ·:_-.-. ·- -- :. ·.. ·... .- - .:_-:.: ':.· .. -- ·.. - . -.. :. part of exposure att south side of gulley. ·

- ---· - ·. :� :-.:.·.. ...- - -=. .. :.-.: = =.::== :- . II Stiale, greenish gray, very silly, pyrilic. Poorly ------· - - . ·------exposed intermitlenlly on slope below main --·- ·------··- -······· 10 outcrop. Beller exposed on south side of gulley. c -u 9 -u rri ::0

Shale, bullish gray, very silly with dark gray 0 7 streaks and 2 dark greenish-gray, very silty rri - - -- pyrilic limestone beds. < - - --- t 0 !i:: 6 - I") ::z: 5 � Shale, greenish gray, very silty with greenish gray, };; 4 l> silly, flow-marked � 3 � limeslane. ::z: ""C ,, g> 2 c:: Shale, greenish gray, silly...... ;:,. Shale, bluish gray, only slightly silly, contains finely divided carbonaceous material. Becomes darker al lowermost part of outcrop in stream bed.

Mccraney North. NE� NE� Sec. 15, SE� S� Sec. 14 and NWl.i M-P4 Sec . 24 , T. 4 S. , R. 7 W. , Pike County, Ill inois. 1" 54 <":/f"bf ;1 I Mccraney North . NE\ NE\ Sec . 15, SE� SE\ Sec . 14 , and NW\ NW\ Sec·. 24 , T. 4 s., R. 7 w. , Pike County, Illinois.

This exposure, the former site of an old high level quarry , is the north end of the type section for the Mccraney Formation which occurs near the top of the bluff . The south end of the section is in the north wall of Mccraney Creek, less than a half mile (0.8 km) to the south . These exposures are part of the Kinderhookian stratotype wh ich continues southward along the bluff for another half mile '\ (0.8 km) south of Mccraney Creek . The stratigraphic extent of the exposure is represented on the Stop 2A diagram.

The close proximity of this section (6 miles, 9.6 km) , which exposes the Mccraney , and the section at Hannibal, wh ich exposes the Loui siana, has led to considerable confusion. In each area there is a single , mottled, seemingly unique , 11thographic limestone underlain by silty shale and overlain by siltstone . In addition , the two limestones have never been found in the same se�tion . Nevertheless , the Louisiana is late Devonian (Siphonodella praesulcata Zone) whereas the Mccraney

is late Kinderhookian (Siphonodella isosticha � �· Cooperi Zone) •

The lower end of the section consists of greenish-gray shale referred to the Saverton Formation . The shale of the Saverton becomes increasingly silty upward and grades into what Moore called the "English River (?) sandstone member" ,of the Hannibal . The siltstone is buff, massive and vermicular. Approximately 28.. feet (8.5 m) below the top of the unit, molds of brachiopods ·and pelecypods are locally abundant . Among the fossils most common are :

Schellwienella chemungensis (Conrad) Chonetes geniculatus White Chonetes ornatus Shumard Chonetes cf. C. illinoisensis Worthen Productella ? sp . Productus curtirostris Winchell Spirifer marionensis Shumard $yringothyris extenuatus Hall Pterinopectin cf. P. laetus Hall Goniophora jennae Winchell Spirifer marionensis and the chonetids are by far the mo st common .

Three-fourths of the species in this fauna are associated with the English River Formation in the Burlington, Iowa area, and even though the name-giver brachiopod Chonopectus fisheri is not present, the siltstone here correlates with the English River "Chonopectus" Sandstone at Burlington , Iowa . However, conodont faunas from � the siltstone at Burlington show it _ to be entirely Devonian in age, wh ereas the conodont faunas from the siltstone here seem to show at least the upper part to be lowermost Mississippian. Because of this difference in age and because Hannibal is available for use , the name English River is not used here .

Because the Horton Creek and the Louisiana Forr.iations are missing in this section, the Devonian-Mississippian contact is located exclusively by the occurrence of Siphonodella. Nine miles (15 km) to the south , the Horton Creek occurs in the bluffs . The Louisiana appears some distance farther south . \

•. FO RMATION SERIES

HANNIBAL SHALE, NUTWOOD MBR. Shale, gray to dark gray,. silty, fissile

� (f) (f) (f) (f) -u -u )> Shale, dark gray, silty fissile, marcasitic, also marcasite nQdul�s z

f"Siitstone, dark gray, some marcasite; interbedded with gray and buff _J_ silty shale hitstone, gray, slightly calcareous; nodules of pyri te, rare calcite geodes . 1e, gre nish-gray, silt fissile overlain ·by tan siltstone F � �� .

Limestone, gray to buff, speckled · JHoRTON CREEK FM dark brown, ool itic, fossiliferous

., .' LOUISIANA\ LIMESTONE Limestone, buffish-gray, irregularly wavy bedaed ; intercal ated.• with buff dolomite, calcite nodules

Limestone, buffish-gray, sublithographic to lithographic, medium-bedded, with dolomite interbeds, calcite nodules

0 rn < 0 z )> z

0 MAQUOKETA SHALE Shale, medium gray to dark green :::0 '---��'--���

Starks Roadcut S E� NE� Sec . 25, T. 54 N., R. 2.W. , Bowl ing Green Quadrangle, P � ke County, Missou�i. 55

REFERENCES

Buschbach , T. c., 1953, The · Chouteau formation of Illinois : Ill. Acad . Sci . Trans ., v. 45, p. 108-115 ; reprinted as lllinois Geol. Survey Circ . 183 .

Collinson Charles, 1961, Kinderhookian Series in the Mississippi Valley , in Nort eastern Missouri and west-central Illinois : Kans . Geol . Soc . Guide h Reprint book. 26th Ann . Fi eld Conf ., Mo GS RI 27 , P• lQQ.... 109 ; Ill . GS ) 1961"".'U�

, Rexroad , c. G., and Thompson , T. L., 1971 , Conodont zonation of the North ; Ill . GS Reprint 1972-A . � American Mississippian: GSA Mem . 127,:p. 353-395

1965 , Mi sissippian Foraminif ra ·.. Conkin, J. E., Conkin , B. M. , and Pike , J. : W� , � . of the United States . Part 2--The Hannibal Formation of northeastern Missouri and western Illinois : Micropaleontology , v. 11, no . 3, PP • 335-359 , pls . 1-2 , text-figs . 1-14 .

· , Conkin, B. M. , and Canis , W •. F., 1968., Mississippian foraminifera of the � United States . Part 3--The limestones- of the Chouteau Group in Missouri and Illinois : Mieropaleontology , v. 14 , no . 2, pp . 133-178 , pls . 1-4 , 16 text-figs ., 42 tabs .

Koenig , J. W. , Martin, J. A. , and Collinson, Charles , 1961, Geologic Road Logs : Kans . Geol .. Soc., 26th Ann . Field Conf. Guidebook , pp . 8-74 . ':

.. Meek , F. B., and Wo rthen , A. H. , 1861b , Descriptions of new Paleozoic fossils from Illinois and Iowa : Philadelphia Acad . Nat . Sci. Proc., p. 128-148.

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Geol •. Survey , Bull . 95 , 26 1 p.

Workman , L. E., and Gillette , Tracey , 19-56 , Subsurface stratigraphy of the Kinderhook · Series in Illinois : Ill . GS RI 189, 46 p. FIELD TRIP SCHEDULE SECOND DA Y- APRIL 28

8:00 AM Leave Holiday Inn, St . Louis-South, ::or sections on Marshall Road, Big Bend Road and Cragwold Road. Drive north on Highway 61 (Lindbergh Rd. ) to Big Bend Road in Windsor Springs about 3/4 mile north of the I-44 Interchange . Follow Big Bend Road westward 1 1/3 miles to its Y with Marshall Road. Follow Marshall Road to the Meramec River flats and the small park on the south side of the road. We will examine the bluff near the big bend in the river then move to crops on Cragwold Road.

11 :00 AM Leave Cragwold Road area and proceed eastward to Geyer Road. Turn south passing beneath I-44 . Beyond I-44 turn left (east) on Watson Road and proceed to Highway 61 (Lindbergh Rd .) . Turn left (north) on Highway 61 and proceed to I-44 Interchange . Turn west on I-44 , proceeding to the Highway 141 (Valley Park) Interchange . Take the first access road on the north side eastward to the bluff (Peerless Park Section) . After examination here , cross over to south side of I-44 .

11:30 AM Leave for lunch. After lunch travel to Columbia, Illinois by going east on I-44 to its junction with I-244 . Take I-244 eastward, crossing the Mississippi Rive r, to an intersection with Illinois Highways 3 and 158. Turn right (south) and proceed about four miles to Columbia Roadcut.

2:30 PM Leave Columbia Roadcut and travel 8 miles southward to Waterloo on Highway 3. Beyond the city square at a stop sign , turn right (west) on Illinois Highway 156 . It will be 10 miles to the head of Dennis Hollow, just east of Valmeye r. Arrive at 3:00 PM.

4:00 PM Leave Dennis Hollow. Enter Valmeyer and turn south along the bluff road. Follow the road for 18 miles to Prai::::-ie du Rocher.

4:25 PM Continue on bluff road, beyond the village , 1 2/10 miles south to a high quarry in the St . Louis and Ste . Genevieve Limestones .

4: 55 PM One-tenth mile to Barbeau Hollow.

5:10 PM Leave Barbeau Hollow . Continue south 91:l miles to T junction with Highway 3. Turn right (south) and follow Highway 3 to junction with Highway 150 just northwest of Cheste r. Follow Highway 150 over toll bridge at Mississippi River where the highway becomes Highway 51. Follow Highway 51 a little more than 4 miles to County Highway H which goes northward (right) to St . Marys. Highway 61 will be encountered just outside St . Marys. Turn right passing through the village to the St . Marys outcrop just north of the village . Pere Marquette 6:00 PM Arrive St . Marys, Missouri . State Park 6:30 PM Leave St . Marys , Missouri; hour to St. Louis via I-55.

THIRD DA Y - APRIL 29

8:00 AM Leave Holiday Inn. Travel to Alton , Illinois via I-44 (west) , I-244 (north) , I-270 (east) and U.S. 67 (north) . In Alton turn left just beyond the Mississippi Rive r bridge and follow McAdam Highway (river road) to Elsah. Total trip about 44 miles. from I- 44 Osceola motel 9:00 AM Elsah, home of Principia College

9:30 AM Continue west to Grafton where the route joins Illinois Highway 100 . Follow northward along the Illinois River bluffs. Cross the river at Hardin . Follow Highway 100 to Kampsville . Turn 0 5 10 15 20 west on Highway 96 at Kampsville , crossing west ward to the Mississippi miles Valley , and then north on Highway 96 to l� miles south of Atlas .

10 :30 AM Atlas South

Con tinued on the other side of page . Third Day Continued

11 :00 AM Leave At las South . Travel l� mi les north to U. S. Highway 54. Turn le ft and proceed to and through Louisiana to County Road NN a little less than a mile beyond the Louisiana city limits. Turn south fo r about 1/2 mile to the road cut section known as Stark 's Roadcut .

LUNCH

11 :30 AM Leave Stark' s Roadcut and return eastward to Louisiana for lunch .

12 :30 PM Le ave Louisiana and return eastward at At las to the junction of U.S. 54 and Illinois 96 .

1:00 PM Leave junction at Atlas going north on Highway 96 to Kinderhook .

1:25 PM Arrive at junction of U. S. Highway 36 and o Illin is 96. Turn left through Kinderhook proceeding northward on Highway 96 through a junction where U. S. 36 goes west. Follow the bluff road , which changes to Highway 57, for 3/4 mile to the sect ion referred to as Mccraney North .

2:00 PM Leave for Ames , Iowa . A suggested route is to follow U. S. 36 through Hannibal to U. S. 63 at Macon . Go northward on U.S. 63 to Oshalossa, Iowa then to I-80 via Iowa Highways 163 and 117. I-80 links with I-35 north of Des Moines.

Bon Voyage !