THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS January 8, 1971 Paper 51 FAUNAL STUDIES OF THE TYPE CHESTERAN, UPPER MISSISSIPPIAN OF SOUTHWESTERN ILLINOIS W. M. FURNISH, W. BRUCE SAUNDERS, D. W. BURDICK, and H. L. STRIMPLE The University of Iowa, Iowa City Present address of W. BRUCE SAUNDERS, Department of Geology, Bryn Mawr College, Bryn Mawr, Pennsylvania PART 1 AMMONOIDS FROM THE MIDDLE CHESTER BEECH CREEK LIMESTONE, ST. CLAIR COUNTY W. M. FURNISH and W. BRUCE SAUNDERS ABSTRACT The index goniatite Lyrogoniatites has been discovered in the Golconda Group, Hombergian Stage, middle Chester Series, of the type area. This ammonoid, L. hartmani FURNISH & SAUNDERS, n. sp., is comparable to species known elsewhere in America; it indi- cates a correlation with the Oklahoma Caney Formation (Delaware Creek Member) and equivalents in Georgia, Alabama, Arkansas, Texas, Utah, Nevada, and Alaska. An equiva- lent faunal zone occurs in the upper Visean Series of Europe, below the usual boundary be- tween Upper and Lower Carboniferous. Strata just below the Chester Series in southwestern Illinois contain the Prolecanites monroensis—Goniatites greencastlensis fauna of late middle Visean age, the only known true Meramecan ammonoids in America. INTRODUCTION In 1951 ALBERT E. HARTMAN found a single a block of limestone near a face in the main quarry goniatite within an abandoned quarry about one- bed, so the source is known rather precisely. half mile west of Richland Creek, in southwestern Nevertheless, several attempts to duplicate the St. Clair County, Illinois, north of the town of discovery, even with HARTmAN's assistance, have Hecker (SW1/4 SW 1/4 Sec. 27, T. 2 S., R. 8 W.). been unsuccessful. During the fall of 1969, DENNIS Mr. HARTMAN, who is a refinery engineer with W. BURDICK found an additional ammonoid in a Socony Mobil, was raised in this area and has currently active quarry, about a mile to the north- collected fossils from the vicinity for many years west of the original locality. This find initiated so he recognized that the goniatite was unique. the thought that still more would be found there, Additionally he was accompanied at the time by a forlorn hope. The second specimen was as- HAROLD H. BEAVER, who substantiated the con- sociated with highly fossiliferous argillaceous ma- clusion that it was an important discovery, the terial used as fill for a roadway within the quarry, first such fossil in the type Chester. Although but can he traced to a section in the quarry face. loose on the surface, this goniatite was found on It is apparent that the two goniatites came from 2 The University of Kansas Paleontological Contributions—Paper 51 beds in the Beech Creek Limestone and were semblage Zone characterize the entire Golconda separated by no more than about ten feet vertically. as a middle Chesteran unit, according to COLLIN- Also, the specimens appear to be conspecific and SON, SCOTT, & REXROAD (1962). Faunal evidence here paratype are described as holotype and of contradicts SWANN ' S reassignment of the Gasper- Lyrogoniatites hartmani FURNISH & SAUNDERS, Homberg boundary; even his own comments sug- n. sp. gest that the Beech Creek is a part of the Hom- bergian, rather than marking the top of the Gas- STRATIGRAPHY peran Stage in the lower Chester, as he indicated. Chester formations have been subjected to as For example, according to SWANN (1963, p. 79) intense scrutiny for biostratigraphic analysis as Pterotocrinus (such as some of those in the Beech any comparable section in America. The work of Creek) with "Large, simple, and forked blades such eminent authorities as STUART WELLER (1914, as well as heavy massive plates characterize the 1920a) and BUTTS & ULRICH (1917) on rocks of Hombergian." Also, it is stated (ibid. p. 83) that the Eastern Interior Basin is classic. Large-scale the Talarocrinus Range Zone (defined by WELLER, petroleum development, particularly about 30 1926) is equivalent to "all fossiliferous Gasperian years ago, accentuated interest in these strata and [Gasperan] rocks except the Beech Creek Lime- provided much additional information. South- stone." From our own observations and on the western Illinois is probably the most important basis of the restricted occurrences of both these area for studies of Late Mississippian rocks and crinoid genera, assignment of the Beech Creek fossils in this country; a radius of a few tens to the Hombergian is logical. of miles here encompasses the type localities of many standard Chester divisions (SwANN, 1963). TIME CORRELATION Although most of the rock-unit names have be- come relatively stable in this area, comparable time No apparent effort has been made to employ subdivisions are not well formalized. SWANN Chesteran stages in the usual sense as broadly (ibid.) has recommended that Genevievan, Gas- recognizable time-stratigraphic subdivisions. The peran, Hombergian, and Elviran Stages be em- stage names proposed for "middle Carboniferous" ployed in a "provincial" sense. Above the Ste. units in western Europe, such as Bollandian, Genevieve, these terms correspond to lower, mid- Pendleian, and Arnsbergian, have similarly re- dle, and upper Chester "groups" of STUART WEL- ceived relatively little attention. The most widely LER (1920a), who also used Okaw for the middle used classification scheme for the European Car- portion. In 1939, J. M. WELLER proposed New boniferous has been based upon fossils; for ex- Design, Homberg, and Elvira as group names, ample the Posidonia (P 1 and Po) Zone I "true- and they have been used in a variety of publica- Goniatites" Zone and upper Dibunophyllum (Do tions including the Mississippian Correlation Chart and D3 ) Zone]. Symbols and mapping units have (WELLER et al., 1948). also been designated, but such numbers and letters There has also been variability in defining the have a meaning only in terms of an individual boundary between lower and middle Chesteran author or country. Visean (Lower Carboniferous) stages (Gasperan and Hombergian). For the and Namurian (Upper Carboniferous) are most most part, differences involve assignment of the often employed in a worldwide sense as series Beech Creek Limestone (SwANN & ATHERTON, names; with lower, middle, and upper correspond- 1948; SWANN, 1963), a relatively thin carbonate ing to stage subdivisions. An agreed-upon bound- rock which is the source of the two goniatites from ary between Lower and Upper Carboniferous St. Clair County. The name Beech Creek was (JONGMANS et al., 1928) generally has been at- derived from southcentral Indiana, near Bloom- tributed to fall within the Chester Series in North ington, but the same thin carbonate beds have America (e.g., MOORE, 1937; MILLER & FURNISH, been designated basal Golconda Group in south- 1940). western Illinois (SwANN, 1963). STUART WELLER Over a period of years, the British Visean and (1926) identified this part of the section on the Namurian goniatite zones have been defined in a basis of a wide-ranging fossil as his Pterotocrinus precise manner (BisAT, 1924; HUDSON, 1945) and capitalis Zone (SUTTON, 1934). Conodonts of the their equivalents have been recognized widely in Gnathodus bilineatus—Cavusgnathus cristata As- Eurasia and Africa. Nearly identical faunal rela- Furnish, Saunders, Burdick, and Strimple—Faunal Studies of Type Chesteran 3 tionships are also apparent in the southern Mid- stated that it is the only spot where he observed continent (MILLER & FURNISH, 1940), Great these particular fossils in hundreds of exposures Basin (YouNcoutsT, 1949), and Alaska (GORDON, examined. An intensive search in the vicinity has 1957). failed to reveal any of these goniatites or other In North America, the greatest problem in Mississippian fossils and the locality is still enig- Upper Mississippian correlation has existed in matic. The entire area was mapped by MCFARLAN attempting to bridge the gap between type Ches- (1929) and in greater detail by GUALTIERI (1967) teran in the Eastern Interior Basin and strata in but their work shows no rocks of Late Mississip- the southern Midcontinent. Although exposures pian age where FISCHER indicated that the fossils of the Upper Mississippi Valley province lie just had been found. Originally, the layer was identi- across the Ozark Uplift about 150 miles from fied as St. Louis (in an unrestricted sense to in- strata of comparable age in northcentral Arkansas, clude the Ste. Genevieve); beds of this age are faunas of the two areas are quite different, the exposed extensively only two or three miles to Arkansas sections containing dark shales rich in the east. Still farther east in the limestone plateau, ammonoids. Consequently, assignments of the fossiliferous limestones occur in the upper New- Meramecan-Chesteran boundary in Arkansas man Formation (GUALTIERI, 1967) of early and (ULRIcx, 1904; GIRTY, 1911; MILLER & FURNISH, middle Chesteran age according to GORDON WEIR 1940; GORDON, 1944; MCCALEB, QUINN & FURNISH, (personal communication) and various authors. 1964; FURNISH, QUINN, & McCALER, 1964; and The reported site of the goniatite locality lies GoRnoN, 1965) have been either vague or contra- approximately adjacent to a major east-west fault dictory. The most comprehensive and significant at Gum Sulphur. The preservation, silicified review of this correlation problem was presented by residuum in a red clay, even suggests that the MooRE (1948) who surveyed the various faunal matrix may be cavern fill. Possibly FISCHER ' S elements. His conclusion, the same as that pre- description deliberately misrepresented the occur- sented earlier (MooRE, 1937) was that the typical rence. Goniatites faunas in America were of early Ches- Over the years, SMITH (1903), ULRICH (1904), teran age, rather than Meramecan. About ten GIRTY (1911, 1915), and others adopted the St. years ago, it became apparent to FURNISH that Louis (including Ste. Genevieve) assignment for MooRE's interpretation was the correct one. A the Crab Orchard fauna and believed it to be rep- number of discoveries have substantiated this resentative of Meramecan goniatites. GIRTY (1911, conclusion. Field studies in association with p.