=tP£ u STATE OF ILLINOIS HENRY HORNER, Governor DEPARTMENT OF REGISTRATION AND EDUCATION- JOHN J. HALLIHAN, Director DIVISION OF THE STATE GEOLOGICAL SURVEY M. M. LEIGHTON, Chief URBANA REPORT OF INVESTIGATIONS—NO. 61 SUBSURFACE GEOLOGY OF THE CHESTER SERIES IN ILLINOIS BY L. E. WORKMAN SUBSURFACE GEOLOGY OF THE IOWA (LOWER MISSISSIPPIAN) SERIES IN ILLINOIS BY J. NORMAN PAYXE Reprinted from the Bulletin of the Ameri- can Association of Petroleum Geologists, Vol. 24, Xo. 2 (February, 1940), pp. 209-236. PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS URBANA, ILLIXOIS 1940 STATE OF ILLINOIS Hon. Henry Horner, Governor DEPARTMENT OF REGISTRATION AND EDUCATION Hon. John J. Hallihan, Director BOARD OF NATURAL RESOURCES AND CONSERVATION Hon. John J. Hallihan, Chairman Edson S. Bastin, Ph.D., Geology Henry C. Cowles, Ph.D., D.Sc, William A. Noyes, Ph.D., LL.D., Forestry Chem.D., D.Sc, Chemistry Arthur Cutts Willard, D.Engr., Louis R. Howson, C.E., Engineering LL.D., President of the University of William Trelease, D.Sc, LL.D., Biology Illinois STATE GEOLOGICAL SURVEY DIVISION Urbana M. M. Leighton, Ph.D., Chief Enid Townley. M.S., Assistant to the Chief Jane Titcomb, M.A., Geological Assistant GEOLOGICAL RESOURCES GEOCHEMISTRY Coal Frank H. Reed, Ph.D., Chief Chemist G. H. Cady, Ph.D., Senior Geologist W. F. Bradley, Ph.D. L. C. McCabe, Ph.D. G. C. Finger, Ph.D. James M. Schopf, Ph.D. Helen F. Austin, B.S. Earle F. Taylor, M.S. Charles C. Boley, M.S. Fuels Industrial Minerals G. R. Yohe, Ph.D. J. E. Lamar, B.S. Carl Harman, B.S. H. B. Willman. Ph.D. Industrial Minerals Robert M. Grogan, M.S. J. S. Machin, Ph.D. Templeton, A.B. J. S. James F. Vanecek, M.S. Oil and Gas Analytical A. H. Bell, Ph.D. G. V. Cohee. Ph.D. O. W. Rees, Ph.D. Frederick Squires, B.S. George W. Land, B.Ed. Charles W. Carter, Ph.D. P. W. Henline, B.S. F. C. MacKnight, Ph.D. Mathew Kalinowski, B.S. James L. Carlton, B.S. A. J. Veraguth, M.S. Frank E. Tippie, B.S. Roy B. Ralston, B.A. Areal and Engineering Geology MINERAL ECONOMICS George E. Ekblaw, Ph.D. Richard F, Fisher, B.A. W. H. Voskuil, Ph.D., Mineral Subsurface Geology Economist Grace N. Oliver, A.B. L. E. Workman, M.S. J. Norman Payne, Ph.D. Elwood Atherton, Ph.D. Merlyn B. Buhle, M.S. EDUCATION EXTENSION Gordon Prescott, B.S. Stratigraphy and Paleontology Don L. Carroll, B.S. J. Marvin Weller, Ph.D. Chalmer L. Cooper, M.S. Petrography PUBLICATIONS AND RECORDS Ralph E. Grim, Ph.D. George E. Ekblaw, Ph.D. Richards A. Rowland, Ph.D. Chalmer L. Cooper, M.S. Physics Dorothy Rose, B.S. R. J. Piersol, Ph.D. Alma R. Sweeney, A.B. M. C. Watson, Ph.D. M. Frances Harper, M.S. Donald O. Holland, M.S. Meredith M. Calkins Consultants: Ceramics, Cullen Warner Parmelee, M.S., D.Sc, University of Illinois; Pleistocene Invertebrate Paleontology, Frank Collins Baker, B.S., University of Illinois. Topographic Mapping in Cooperation with the United States Geological Survey. This Report is a Contribution of the Section of Geological Resources, Division of Sub- surface Geology. August 1, 1939 SURVEY ILLINOIS STATE GEOLOGICAL 3 3051 00005 6857 Volume 24 Number 2 BULLETIN of the AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS FEBRUARY, 1940 SUBSURFACE GEOLOGY OF CHESTER SERIES IN ILLINOIS 1 L. E. WORKMAN8 Urbana, Illinois ABSTRACT The Chester series underlies most of the southern half of Illinois east of East St. Louis. Except where they have been removed by post-Chester erosion, all of the forma- tions in the standard Chester section can be identified in the area. Producing formations are the Cypress and Bethel sandstones, both of which are in the lower part of the Chester series. The maximum known thickness is 1,450 feet at a point in the most southerly part of the area. Because of northward thinning of individual formations, the original thickness of the entire section in the northern part of the area was probably half of this. Uplift, warping, and peneplanation previous to the deposition of Pennsyl- vanian sediments caused truncation of the series throughout the basin and scalping of local structures. The isopach map indicates two major pre-Pennsylvanian anticlinal areas in which are located a large proportion of the Illinois oil fields, one the LaSalle anticline, and the other an uplift extending southeast from the region of Sorento. INTRODUCTION The Chester series occupies an area in the southern half of Illinois known as the Illinois basin. All the formations of the standard Chester section are present in the basin and have formerly had a much wider extent than at present. They are essentially parallel with no great unconformities separating them and are likewise es- sentially parallel with the underlying formations of the Iowa series of the Mississippian system. However, they were warped, tilted south- ward, and truncated previous to the deposition of Pennsylvanian strata, causing the pattern of formations shown in the accompanying areal geologic map of the Chester series below the Pennsylvanian system (Fig. 1). The stratigraphic relations of the Chester formations are shown in the geologic cross sections (Fig. 2). 1 Read before the Association at Oklahoma City, March 24, 1939. Manuscript re- ceived, August 6, 1939. 2 Subsurface Division, Illinois State Geological Survey. 209 2IO L. E. WORKMAN AREAL GEOLOGIC MAP X OF CHESTER SERIES BELOW PENNSYLVANIAN SYSTEM BY L.E. WORKMAN LEGEND A-B, C-D LINES OF CROSS - SECTION • ' LOCATION OF WELL IN CROSS - SECTION SCALE 10 20 30 MiteS ^ *ff** BOUNDARY OF PENNSYLVANIAN MARCH IF, 1939 SN N ILLINOIS STATE GEOLOGICAL SURVEY Fig. i. —Areal geologic map of Chester series below Pennsylvanian system. GEOLOGY OF GilESTER SERIES IN ILLINOIS 211 Kinkaid formation.—The Kinkaid formation is the topmost for- mation of the Chester series. In the Illinois basin it consists mostly of limestones and interbedded shales, but there are also some sand- stone, siltstone, and chert beds. In a well in northern Pope County, in the southern part of the basin, the formation reaches its thickest development and is described as follows. Thickness Description of Strata in Feel Limestone, mottled, very fine- to coarse-grained; some shale, dark gray. ... 60 Shale, green and red; limestone, red and brown 15 Limestone, argillaceous, very fine-grained; shale, partly silty, gray 40 Shale, silty, grading to siltstone and sandstone 20 Limestone, argillaceous, mottled to dense, in places cherty, very fine- to coarse-grained; shale, gray to black 35 Shale, silty, dark gray to red and green; some limestone beds 15 Total 1! The limestones are more or less cherty, being especially cherty where they lie close under the Pennsylvanian strata. The strata ex- tend laterally without important variations. The lowest limestone zone is the one encountered directly under the Pennsylvanian strata in drilling at most locations in Wayne and eastern Marion counties. The Kinkaid formation thins northward under the erosional un- conformity at the base of the Pennsylvanian system. Degonia sandstone.—In areas of its thicker development, the Degonia sandstone is calcareous, very fine- to medium-grained, and white to light green and gray in color. As the formation becomes thin- ner laterally it becomes finer-grained, silty, and argillaceous and grades to carbonaceous, dark gray shale. In places it has a quartzitic appearance due to the cementing of the sand grains by silica. The Degonia sandstone is 100-125 feet thick in Jackson County which is in the southwestern part of its area of occurrence in the Illinois basin. It thins eastward to about 50 feet in White County and northeastward to about 25 feet in northeastern Marion County. Clore formation.—The Clore formation is variable in character. It consists of beds of buff to dark brownish gray, lithographic to coarse-grained, more or less argillaceous limestone alternating with red and green to dark gray shales, and contains also some sandstone beds. Chert, sand, oolites, and dolomite occur irregularly in the lime- stones. The lower limestones are more dolomitic than the upper, grad- ing in places to dolomite. The Clore formation ranges irregularly from 50 to 100 feet in thickness, becoming thicker toward the south. Palestine sandstone.—The Palestine sandstone is generally cal- careous, light gray to white, and very fine- to fine-grained. It contains J.33J Nl SS3N>OIHJ. u bo O J.3 3J Nt 5S3NM0IHJ. GEOLOGY OF CHESTER SERIES IN ILLINOIS 213 dark gray, carbonaceous, silty partings and some interbedded dark gray, silty to sandy, carbonaceous shale. The contact with the over- lying Clore is in some places difficult to distinguish because of the presence in both formations of this type of dark carbonaceous shale. The sandstone averages 40 feet in thickness in the western part of the Illinois basin, in Washington and Jackson counties, and it thickens eastward to 100 and 120 feet in the eastern part. Unlike most of the other Chester formations, the Palestine sandstone does not thin northward, being nearly as thick in Effingham County as in Gallatin County. Menard formation.—The Menard formation is best developed in the southwestern part of the basin, in Jackson, Randolph, and Perry counties, where it may be divided into five zones: three zones of shale at the top, middle, and bottom with two alternating zones of lime- stone. These divisions of the Menard, however, may be observed elsewhere throughout its area in the basin. The limestone zones are 20-50 feet thick. The limestones are buff to brown and dark brownish gray, more or less argillaceous, and very fine- to coarse-grained in texture.