BEDROCK GEOLOGY OF CHESTER QUADRANGLE Illinois Department of Natural Resources ILLINOIS STATE GEOLOGICAL SURVEY RANDOLPH COUNTY, ILLINOIS STATEMAP Chester-BG William W. Shilts, Chief Joseph A. Devera 2006 A’ &cv Mp Mp Mp Mc &cv e" Mk 102 Mk 20 k" N J Md &cv Mp Mc N J 9 N o J N NJ J N Mc 10 N 50 J N oN J e" J J Md 802ªÜ 2300 Ü o ª k" Mp o 123 Mc 2 2 k"168 Mc 99e" Mc e"142 EXPLANATION e"27 Mp E o Md N J 2 e" T e" 182 PENNSYLVANIAN &cv Caseyville Formation Morrowan 122 Mp N Mp Mp J e"121 Unconformity e" 240k" 138 N J e" 32 28e" Mk Kinkaid Limestone k" Mc N Mc 170 J Mm e" 222 N J Md Degonia Formation e Mm Md Mc e" JN 480 Mp N J N Mc Clore Formation J N J N J N e J o Mc 2 Mp Palestine Formation k" Mc Mp MISSISSIPPIAN Chesterian Mm 152e" Mp 37e" Mp Mm Menard Limestone Mp e" 90 Mp Mc Waltersburg Formation Mm Mwvt Vienna Limestone Mp Tar Springs Formation Mm Mgd Glen Dean Limestone oÆ 2 Hardinsburg Sandstone Mhg Mm Golconda Formation Mm Mp Lower Pope Group Mlpu Mp A Undifferentiated Mp Mm Mc Mp e" Mp 250 501 k" Mp Mm Mc 242 k" Symbols Mgd Mm e" e" 63 10 Strike and dip of bedding; number 29 indicates degree of dip Mwvt k" Horizontal bedding " 162 Mc e 35 Outcrop of special note, map unit contact E or good exposure at time of mapping Mhg Mhg Mp Mc Mc Type section T Mc Æ Sandstone quarry abandoned Mm k" 159 545 Drill Holes k" e" from which subsurface data were obtained 350 E Mp Md Mgd e" Water well Mp Md T Mp Mc ª Dry oil – test hole Md Md Numeric label indicates total depth of boring in feet. k" 120 Tpc Unit label denotes formation at bottom. (br = bedrock) Mp Dot indicates location accurate within 100 feet. Md e" 118 Line Symbols dashed where inferred, dotted where concealed T Mc E Contact Mm Fault; bar and ball on downthrown side k" 82 A A� Line of cross section Mm Note: Well and boring records are on file at the ISGS Geological Records Unit and are available online at the ISGS Web site. Mhg Mp Mc e Mc Mlpu o Mm 2 Md Mgd o Mwvt 2 Mp o Mc 2 65 e" Mhg Md Mc Mp Md Base map compiled by Illinois State Geological Survey from digital data provided by the SCALE 1:24,000 Geology based on field work yb J. Devera, 2005–2006. United States Geological Survey. Raster Feature Seperates. Compiled from imagery dated 1 1/ 2 0 1 MILE 1968. Revised from imagery dated 1993. PLSS and survey control current as of 1970. Con- Digital cartography by J. Domier, M. Widener, and M. Bentley, Illinois State Geological 1000 0 1000 2000 3000 4000 5000 6000 7000 FEET tours and elevations current as of 1968. Map edited 1996. Survey. 1 .5 0 1 KILOMETER North American Datum of 1983 (NAD 83) This research was supported in part by the U.S. Geological Survey, National Cooperative Projection: Transverse Mercator Geologic Mapping Program under USGS award number O5HQAG0079. 10,000-foot ticks: Illinois (east zone) and Missouri (west zone) State Plane Coordinate Systems (Transverse Mercator) BASE MAP CONTOUR INTERVAL 20 FEET The views and conclusions contained in this document are those of the authors and 1,000-meter ticks: Universal Transverse Mercator grid system, zone 16 SUPPLEMENTARY CONTOUR INTERVAL 5 FEET should not be interpreted as necessarily representing the official policies, either expressed NATIONAL GEODETIC VERTICAL DATUM OF 1929 or implied, of the U.S. Government. Released by the authority of the State of Illinois: 2006 The Illinois State Geological Survey, the Illinois Department of Natural Resources, and the State of Illinois make no guarantee, expressed or implied, regarding the correctness of the interpretations presented in this document and accept no liability for the consequences of decisions made by others on the basis of the information presented here. The geologic interpretations are based on data that may vary with respect to accuracy of geographic location, the type and quantity of data available at each location, and the scientific and technical qualifications of the data sources. Maps or cross sections in this document are not meant to be enlarged. 1 /2 ° ROAD CLASSIFICATION ADJOINING 1 2 3 QUADRANGLES Primary highway, Light-duty road, hard or 1 Evansville H 2 Walsh hard surface improved surface 3 Steeleville 4 5 Secondary highway, 4 Kaskaskia hard surface Unimproved road 5 Welge RUE NORT For more information contact: T 6 Lithium MAGNETIC NORTH Illinois State Geological Survey 6 7 8 7 Belgique 615 East Peabody Drive 8 Rockwood APPROXIMATE MEAN Interstate Route U.S. Route State Route Champaign, Illinois 61820-6964 DECLINATION, 2006 (217) 244-2414 http://www.isgs.uiuc.edu STATEMAP Chester-BG Sheet 1 of 2 Structural Geology State Correctional Center. This formation is well exposed along the Mis- sissippi River bluffs from Chester to Rockwood, Illinois. MEMBER A Sandstone weathers brown white and sugary when freshly exposed, weath- THICKNESS The strata through out the study area are relatively flat but have a regional FORMATION or GRAPHIC COLUMN ers to tan and brown with reddish staining from secondary iron, coarse to fine (FEET) strike about N 50°W with a 2° dip to the northeast in the southwestern area Special notations (see explanation on map) show good exposures of these BED UNIT grained, poorly to moderately well sorted, subrounded to rounded, quartz arenite SERIES of the quadrangle. On the eastern side of the quadrangle strike changes to three type sections. SYSTEM and contains quartz pebbles and granules and locally chert granules. Liesagang nearly north south with a slight dip to the east. banding and iron staining common in this unit. Primary sedimentary structures include: current ripple-marks, load casts, tool marks and large-scale cross bed- AN Economic Geology ANIAN V ding. Fossils present are mainly plant fossil, sandstone impressions. The basal In the northeastern corner of the study area two parallel faults were en- OW Caseyville 0–60’ A contact is unconformable and shows active erosion into the unit below by incor- countered both with an east-west trend and downward stepping on the Limestone Aggregate north side of both faults. The fault farthest north occurs in section 21 and porating Mississippian invertebrate fossils and fossiliferous chert into the basal There are a number of abandoned limestone quarries in the southwestern MORR quartz pebble conglomerate. 22, T6S, R6W. Exposures along Little Mary’s River yield Palestine Sand- portion of the Chester Quadrangle along the Mississippi River bluff. These PENNSYL stone juxtaposed with upper Clore which gives a minimum throw ranging operations quarried the Glen Dean Limestone. The Glen Dean to Menard Cave Hill B Limestone is a medium to dark gray fossil lime mudstone to wackestone. The from 40 to 80 feet down to the north. The fault also shows Palestine juxta- Limestone was quarried in what is now the Menard Correctional Center. Kinkaid 0–40’ B basal unit is a dark micritic dense carbonate rock that contains dark chert and posed with basal Degonia Sandstone in a side ravine which yields a maxi- Currently, there are no active limestone quarries in this quadrangle. Areas Negli Creek shows conchoidal fracture. The overlying limestone is more thinly bedded having mum range of 80 to120 feet down to the north. The Chesterian section and for quality limestone occur in the southwestern corner of Section 29, T7S, shaly layers and abundant fossils invertebrates like spiriferid brachiopods, fenes- the overlying Pennsylvanian sandstones of the Caseyville Formation show R6W. Here the Menard Limestone is exposed but the higher quality Glen trate bryozoans, small rugose corals, proetid trilobite pygitia, pelmatozoa, and signs of faulting. The strike of the fault changes as it crosses the Little Dean is only 50 feet below the base of the Menard Limestone because of a echinoid spines. The basal contact is sharp but conformable. Mary’s River from east-west to northwest. The second fault, about a mile condensed interval between the Waltersburg and Tar Springs Sandstones. and a half south in Sections 31 and 32, T6S, R6W was found by drill hole C Sandstone with siltstone is white to tan, fine grained, well sorted, quartz information and bedrock mapping along Tindall Creek. This fault parallels arenite. This unit ranges from thin to thick bedded and created a large bluff form- Sandstone Degonia 0–100’ C the aforementioned fault which also has an east-west strike and turns to the ing sandstone in the southeastern corner of the map. Low angle cross bedding is Sandstone blocks were quarried from an area in the southeastern part of common with planar, ripple, flaser, and micro-cross lamination are commonly northwest as it crosses Tindall Creek. The Menard Limestone is juxtaposed Section 4, T7S, R6E for the foundation of a covered bridge that crossed rhythmic near the top of the formation. Some shale is present in the lower part with the Clore Formation which gives a maximum through of 60 to 80 feet the Little Mary’s River. It was the old route to Fort Kaskaskia. The large of the formation as well as in the upper most part that becomes silty. The base of down to the north. Both faults are probably related to the western-most blocks of sandstone came from the tabular bedded portion of the Palestine this sandstone can be locally erosional but gradational in the study area.