Map 10 2001

George H. Ryan, Governor

Department of Natural Resources Brent Manning, Director ILLINOIS STATE GEOLOGICAL SURVEY William W. Shilts, Chief Geologic Road Map of Illinois: N Natural Resources Building East Dubuque Warren 615 East Peabody South Beloit Richmond Antioch 84 CHAIN- 173 Champaign Illinois, 61820-6964 APPLE RIVER Rockton 173 O-LAKES Zion ILLINOIS CANYON LAKE BEACH LE-AQUA-NA Lake Summerset Galena 78 Durand Roscoe 94 Surface Deposits and Landscapes 26 76 132 Harvard Lena 75 2 Fox Lake 251 90 14 47 83 Machesney 173 Waukegan MCHENRY DAM E 20 Stockton 70 Park ROCK CUT & LAKE DEFIANCE W Pecatonica McHenry North Woodstock David A. Grimley, Barbara J. Stiff, and Michael J. Andrew Loves Park 23 60 73 Belvidere 12 20 Marengo 176 41 Freeport 176 Mundelein Winnebago 20 Lake Forest Surface deposits compiled from Hansel and Johnson (1996), Lineback (1979), and Willman and Frye (1970) 84 59 Rockford Cherry Crystal Lake 14 22 90 Huntley Lake Zurich Highland Park S Forreston MISSISSIPPI Carpentersville PALISADES 72 Byron 68 Genoa 94 Savanna Mount Carroll Lanark Arlington 26 2 Kirkland 62 Hts. 72 Hampshire glacial outwash Mount Morris Mt. Prospect Evanston lake 39 20 Elgin Des 64 LOWDEN Skokie Driftless 47 Schaumburg Plaines Lake Michigan 52 290 WHITE CASTLE 64 41 Area PINE ROCK Oregon Sycamore 31 Milledgeville Polo FOREST 19 Michigan 19 St. Charles 20 LOWDEN-MILLER Rochelle 43 De Kalb 64 88 38 Oak Chicago 38 Elburn 59 355 Park 290 Fulton 2 Ashton 251 88 Wheaton Chicago MORRISON- Dixon Cicero ROCKWOOD 25 294 34 88 23 Morrison Sterling Downers 30 Rock Falls Waterman Hinckley Sugar Grove Naperville Grove 50 41 A 84 78 30 Aurora IOWIOWA 55 12 90 26 Amboy SHABBONA LAKE Oak A. Grimley 34 Bolingbrook 83 Lawn r PROPHETSTOWN 172 Plano 45 Erie ive Sandwich 171 88 R Prophetstown Yorkville 30 94 k LEE COUNTY 52 Port Byron c o (GREEN RIVER) R Somonauk Orland Park

photo: David 6 Earlville SILVER SPRINGS 126 7 34 Tinley 71

Fast-flowing glacial meltwater streams deposited coarse sand and Walnut Park 1 photo: Leon R. Follmer W W Mendota 47 92 92 80 gravel (known as outwash) in front of margins. This photo East Sheridan Downtown Chicago is built on the bed of a former . Moline Joliet Chicago Peoria i of outwash is from the margin of the next to last glaciation near s 82 52 Heights During the latter phases of the last glaciation, Lake Michigan's Rock MolineSilvis Park c Mt. Carroll in northwestern Illinois. Deposits such as this make Colona Minooka Island 45 Forest outlet to the northeast was blocked at times by . Thus, on 78 394 o excellent aquifers for groundwater supply when found below the 6 53 Manhattan several occasions, the level of ancestral Lake Michigan near 92 Geneseo HENNEPIN 89 50 n water table. However, such aquifers are susceptible to contam- Andalusia Coal Valley CANAL Channahon Chicago was many feet higher than today. The lake basin itself s PARKWAY 251 6 i ination if not overlain by a fine-grained or clay deposit to 92 Milan ILLINOIS & was originally formed and deepened during several glaciations by n Ladd Morris MICHIGAN CANAL impede the infiltration of surface water contaminants. 80 DES Beecher Orion 80 the scouring of flowing to the south.

INDIANA 94 La Salle r PLAINES 52 Wyanet Princeton De Pue 6 Marseilles ive Peotone JOHNSON- 26 Peru STARVED ROCK is R GOOSE LAKE Cambridge SAUK 88 no E Illi PRAIRIE Wilmington TRAIL Spring Ottawa ILLINI Diamond river alluvium Lakewood Shores p 81 Valley MATTHIESSEN Seneca 113 57 Oglesby Coal City i Granville 113 s 71 23 Braidwood Manteno 17 o Grant Park 82 Kewanee d 17 e 67 Momence in Aledo Galva 93 Gardner KANKAKEE 102 rg 29 RIVER 114 ma 34 170 55 Bradley 91 Streator Henry 18 17 # 17 Toulon Kankakee 17 Dwight 135 26 Wyoming BIG Herscher St. Anne RIVER 74 167 179 V 17 e Chebanse Toluca r Odell 78 Lacon m 94 i 180 li o 115 IROQUOIS COUNTY DELABAR MARSHALL 117 39 n Galesburg R 23 MISSOURI COUNTY Oquawka 164 iv Princeville Chillicothe e Clifton 90 r Washburn Monmouth # Pontiac pre-Illinois 164 Minonk Knoxville 88 116 St.Louis JUBILEE Rome 116 74 COLLEGE 91 WOODFORD 52 Episode 34 COUNTY 89 47 45

I photo: Leon R. Follmer l Abingdon photo: Joel M. Dexter margin l Metamora i Roanoke 24 n Postglacial river sediments range from clayey silt to sand and 8 Peoria 251 This view looking north towardsMoraine View State Park shows Elmwood Hts. Fairbury Forrest Gilman Sheldon o Germantown Hills El Paso Grindley Chenoa Watseka gravel. Faster flowing rivers deposited coarser layers of sand and Roseville Peoria 24 an end moraine (the ridge on the horizon). End , such as i gravel. During glacial times, many large, fast-flowing rivers carried 116 Chatsworth this oneeast of Bloomington-Normal, mark places where an ice s Hanna 474 Onarga 49 94 City Eureka large sediment loads. Today, the sand and gravel outwash 116 55 front has remained stationary for tens to hundreds of years. In E n 96 Farmington West Washington 117 pi i deposited by these streams lies beneath more recent, finer- 67 Peoria Illinois, end moraines contain largely unsorted sediment (till), a s g East Peoria 54 Milford o r grained alluvium in many major river valleys, and below other 78 Lexington mixture of clay, silt,sand and gravel, deposited by moving or d a Dallas City Bartonville M e m glacial deposits elsewhere. These deposits are major sources of 94 97 74 Hudson ac melting ice. These ridges, which form transverse to the ice flow PEKIN Marquette kin 57 96 LAKE Hts. aw groundwater. In Illinois, about one-third of the total population and Glasford River 1 direction, outline the shape of former ice lobes. Nauvoo La Harpe Canton 24 Morton 165 90% of the rural population rely on groundwater for drinking. Bushnell 9 Pekin NAVOO 9 Mackinaw 9 9 Tremont This digital shaded relief image of Normal 115 till plain Cuba SouthPekin Illinois (from Abert, 1996) shows the unglaciated 94 RICE Hoopeston ARGYLE Macomb 9 (Wisconsin Episode) sand dunes 95 LAKE landscape of the state. Major river LAKE 100 Gibson City 9 valleys, glacial ridges, and lake Bloomington Paxton Carthage 122 # V can be seen. Compare with Colchester Lewiston Manito Minier er !$ m Rossville 29 ili the map of surface deposits. Arrows Hamilton MORAINE VIEW o 55 n indicate the approximate direction of L DICKSON R KENTUCKY a SAND RIDGE Le Roy i Warsaw !$ MOUNDS Delavan v M e

o r glacial ice flow. in 155 Fisher e Heyworth !$ R Havana !$ 96 iv 119 e Rantoul r Atlanta 47 Astoria Farmer City Thomasboro 101 ANDERSON 97 LAKE 74 Lake of the Woods WEINBERG-KING 24 10 Mason City 54 67 45 Danville Mahomet SAND PRAIRIE- Clinton KICKAPOO SCRUB OAK Lincoln 61 10 48 !$ Rushville 74 10 # SANGANOIS 94 29 WELDON Champaign Urbana St Joseph Oakwood Catlin Tilton 100 RAILSPLITTER SPRINGS 72 Savoy 99 LOUIS H. Homer BARKHAUSEN 78 Maroa Sidney Westville Petersburg Monticello Camp Point 103 Mount 45 Philo 24 Beardstown Pulaski photo: Leon R. Follmer

photo: Joel M. Dexter Tolono Quincy 24 Georgetown Mount Sterling 121 ROBERT This aerial view of a till plain of the last glaciation (Wisconsin Sand dunes in Illinois occur primarily where sandy glacial melt- 125 Williamsville Virginia 54 ALLERTON Warrensburg PARK Episode) is from Champaign County, east-. Erosion water deposits were reworked by wind action. These dunes SITE M 123 Athens # SILOAM 124 Forsyth Bement SPRINGS of former hills by glaciers and filling in of valleys with glacial formed mainly towards the end of the last glaciation. Dune shape Ashland 29 Cerro Gordo 130 99 97 105 deposits contributed to the flatness of this landscape. Washing of and orientation indicate prevailing winds from the west and north- 104 Sherman Decatur Villa Grove sediment into former lakes and low areas during permafrost west, just as the Midwest currently experiences during the late fall, Riverton Harristown 172 Meredosia 125 105 conditions also contributed to the flatness. The landscape has winter, and early spring. This photo is from a dune field in north- Payson 72 104 Long Creek Atwood Tuscola Chrisman 123 iver remained virtually unchanged because, from a geological eastern Illinois near Kankakee; however, many dunes also occur R 36 96 on 36 standpoint, there has been little time for erosion (only 18,000 in the western part of the state such as at Sand Ridge State Park. Springfield am LINCOLN TRAIL SPITLER Rochester ng HOMESTEAD 48 WOODS 100 Jacksonville Sa Mount Zion 49 years since glaciation here). Agricultural fields in these areas generally require irrigation 107 36 Lovington Arthur WALNUT 106 Griggsville 72 because the sandy soils are porous and thus do not retain water Barry Blue Mound 133 POINT Macon Arcola well. 72 South Jacksonville 121 ridged drift 104 SANGCHRIS Chatham LAKE Stonington Bethany Winchester 29 32 133 Paris dissected till plain # 106 Moweaqua Sullivan (pre-Illinois Episode) Pittsfield Waverly Pawnee Kinkaid 128 Auburn 104 267 45 130 16 67 Divernon 1 Taylorville 100 EAGLE 106 Assumption CREEK WOLF Mattoon 54 55 CREEK Roodhouse Virden 48 96 Pleasant Hill 16 111 29 Charleston White Hall Girard Windsor Morrisonville 16 FOX RIDGE 4 Shelbyville Marshall 40 A timetable of glacial and episodes Pana during the last 1 million years in Illinois Greenfield 4124)2 HIDDEN Neoga LINCOLN Martinsville (modified from Killey, 1998). SPRINGS 121 TRAIL 108 Casey 96 Carlinville Nokomis Toledo Carrollton 70 108 32 Greenup BEAVER DAM 127 16 100 photo: Leon R. Follmer The low ridge in the distance is composed largely of sand and Hardin 4 16 33 1,000,000 267 gravel, deposited by waterflowing in or in channels Teutopolis photo: Leon R. Follmer Gillespie Litchfield Hillsboro RAMSEY LAKE beneath glaciers. When the ice melted away, elongate hills or 16 Jerseyville On former till plains of the oldest glaciations, the landscape has 67 Benld 128 ridges were left behind because of the immense quantity of Effingham Mount Olive 185 40 stream sediment and other glacial sediments deposited here. been greatly eroded by streams cutting laterally and downwards 138 Altamont 49 into the earth. Wear and tear, over perhaps 450,000 years, has Brighton SAM PARR These ridges, common in south-central Illinois, are oriented in the Bunker Hill St. Elmo 33 Palestine formed this hilly erosional landscape in Adams County, east of PERE MARQUETTE Oblong direction of ice flow. This photo is from Logan County northeast of Staunton Quincy in western Illinois. Robinson Springfield. 70 Newton Godfrey 127 Vandallia Surface Deposits and Landforms 3 159 33 Greenville 140 (Colors of map units match picture frames; map units in legend are Bethalto 185 grouped by age with oldest units at bottom and youngest units at top.) Alton 140 45 130 till plain Wood River (Illinois Episode) loess 143 157 55 3 4 Deposits of the Last Glaciation (Wisconsin Episode) 37 111 Edwardsville 70 143 Louisville and Recent Deposits 270 Glen Carbon 143 Olney RED HILLS Lawrenceville 50 159 Troy Modern stream sediments in valleys (recent) and glacial 40 Highland 127 51 250 Sumner Granite City 57 STEPHEN A. Bridgeport HORSESHOE LAKE FORBES Flora outwash (last glaciation) on terraces and plains ELDON HAZLET []Cahokia and Henry Formations 3 Collinsville 16 1 255 Salem L 159 Carlyle Odin it Breese 50 tle Lake silt and clay on flat plains or terraces (mainly last East St. Louis O’Fallon Lebanon Trenton W FRANK 50 Sandoval ab SOUTH SHORE a glaciation) HOLTEN Beckenmeyer s Fairview h Cahokia Heights R []Equality Formation 15 Germantown Central City ive 158 New Baden 161 r Windblown sand in dune forms or thin sheets (last glaciation) 161 161 SAM DALE 255 Belleville West Mascoutah LAKE Salem []Parkland Sand Wamac Centralia 45 Windblown silt (loess) generally thicker than 20 feet blankets Millstadt 4 Municipalities Columbia 158 Freeburg 177 Mount Carmel upland surfaces in these areas (last glaciation) 15 Okawville 16 Fairfield []Peoria and Roxana Silts Smithton 64 37 Albion 13 15 15 photo: Leon R. Follmer photo: Leon R. Follmer Wayne City S Mostly glacial till (an unsorted mixture of clay, silt, sand, and Waterloo Mount Vernon ki BEALL The till plain of the next to last glaciation (Illinois Episode) is quite 15 lle WOODS Loess deposits (windblown silt) were derived from fine-grained New Athens Nashville t Fo gravel) in broad ridges (last glaciation) rk 130 flat but has less extensive areas of flat land than the till plain of []Wedron Group (in end moraines) Chicago sediment that accumulated in major river valleys during glacial 156 153 15 the last glaciation (Wisconsin Episode). More time for erosion by 159 Grayville times. Strong winds picked up silts deposited by meltwater 64 streams has led to a somewhat more dissected landscape. The Mostly glacial till in flat landscapes (last glaciation) 3 Marissa WASHINGTON COUNTY Greater than 200,000 streams, forming largeclouds of dust that settled out mainly to the last glacier in this area melted away approximately 130,000 years []Wedron Group (in till plains) east and southeast of the river valleys. Loess deposits, as much Red Bud 127 148 ago. as 100 feet thick on bluffs proximal to major river valleys, quickly 142 242 thin downwind to the east and southeast. Most of Illinois is WAYNE r 13 51 e 154 FITZGERRELL 14 v Deposits of the Next to Last Glaciation (Illinois Episode) covered by at least 2 feet of loessal silt, providing our state with i R Sparta some of the best agricultural soils in the world. This photo is from a McLeansboro i Sesser Carmi k Sand and gravel in outwash valleys and silt and clay in former s Pinckneyville bedrock Calhoun County, west of Pere Marquette State Park. a 155 k 154 14 s glacial lake plains a K 4 HAMILTON []Pearl Formation and Teneriffe Silt 57 COUNTY Du Quoin (DOLAN LAKE) 1 RANDOLPH Sand and gravel, with some till and clay, in glacial ridges COUNTY 15 Benton Norris City Steeleville PYRAMID []Hagarstown Member of Pearl Formation Champaign 50,000– 200,000 14 142 Christopher 34

Mostly glacial till in flat to gently rolling landscapes Chester 184 Zeigler 149 141 []Glasford and Winnebago Formations 20,000– 50,000 4 West Frankfort (not shown in the Chicago Metro Royalton 45 Parks and Recreational 3 Alton West Area) 151 Johnston City Eldorado Areas LAKE Ridgway MURPHYSBORO De Soto Herrin 34 Deposits of an Earlier Glaciation (pre-Illinois Episode) Cambria Roads Energy Carterville Mostly glacial till in flat landscapes to rolling hills MISSISSIPPI Harrisburg PALISADES State Parks 13 Marion 5,000 20,000 Murphysboro Crainville SALINE COUNTY Shawneetown []Wolf Creek Formation Chillicothe – 13 13 1:760,320 scale Carbondale (not shown in Chicago Metro West Carrier Mills (one inch equals approx. 12 miles) or St. Louis Areas) SAND RIDGE 64 Interstate Highway 148 State Forests 37 Near-Surface Bedrock Interstate Exit 3 GARDEN OF 0 5 10 15 20 Miles Galena 2,000– 5,000 127 166 THE GODS photo: Joel M. Dexter (in areas not traversed by glaciers) (not shown in Chicago Metro West Spectacular scenery in Garden of the Gods State Park where or St. Louis Metro East Areas) ANDERSON State Conservation Area Interstate Rest Area LAKE GIANT CITY erosion of sandstone bedrock outcrops has created cliffs and Mostly limestone, dolomite, shale, sandstone, and coal in hilly Cobden 45 145 1 to steep terrains. Sediments were deposited and indurated 50 U.S. Highway TRAIL OF 34 steep canyons. Glaciers never reached this far south in Illinois, SAND PRAIRIE- TEARS 9=HI=M 0 10 20 30 Kilometers 1,000 2,000 SCRUB OAK 51 FERNE CLYFFE which explains the high relief of this area—more time (millions of millions of years before the . – Other Natural Areas 146 CAVE-IN-ROCK []Mesozoic and Paleozoic bedrock (not shown in Chicago Metro West 15 State Route Anna years) has been available for weathering and stream erosion to or St. Louis Metro East Areas) carve the landscape. This photo also shows what much of Illinois Jonesboro 146 Rosiclare UNION COUNTY DIXON may have looked like just prior to glaciation. 57 Vienna SPRINGS 24 146

e r s ch Riv e

Ca rn ht:gaitdlnsaees fBloomington-Normal of east landscape glaciated photo: Front

akpoo nlcae adcp nsuhrms Illinois southernmost in landscape unglaciated photo: Back 146 169 References Cited 145 127 Abert, C.C. (1996), Shaded Relief Map of Illinois: Illinois State 51 MERMET LAKE 3 Geological Survey Illinois Map 6, Scale 1:500,000. 37 45 Hansel, A.H., and W.H. Johnson (1996), Wedron and Mason HORSESHOE Metropolis Data Sources LAKE Near-surface geologic deposits were compiled from Hansel Groups: Lithostratigraphic Reclassification of Deposits of the Brookport and Johnson (1996), Lineback (1979), and Willman and Frye Wisconsin Episode, Lake Michigan Lobe Area: Illinois State FORT MASSAC Mounds (1970). Areal extents of municipalities, recreational areas, Geological Survey Bulletin 104, 116 p. 3 and roads were obtained from the Illinois GIS (Geographic Illinois Geographic Information System (1996),Volumes 1 and 2, Information System) database (1996). This GIS data can be Digital GIS Database of Illinois: Illinois Department of Natural aquired from http://www.isgs.uiuc.edu/nsdihome. Resources (CD-ROM) . Cairo Lineback, J.A. (1979), Quaternary Deposits of Illinois (Map): Illinois FORT DEFIANCE Acknowledgments State Geological Survey, Scale 1:500,000. Many helpful suggestions for the text were provided by ISGS Willman, H.B., and J.C. Frye (1970), Stratigraphy of staff, particularly Ardith Hansel, Myrna Killey and Jon Good- Illinois: Illinois State Geological Survey Bulletin 94, 204 p. win. Leon Follmer and Joel Dexter provided many of the

tiff photos which surround the map. Pam Carrillo immensely helped in designing and drafting the layout. Don Luman and Andrew For Further Reading Jane Domier provided helpful cartographic advice. Killey, M.M (1998), Illinois' Ice Age Legacy: Illinois State Geological Survey GeoScience Education Series 14, 66 p.

Surface Deposit and Landscapes

Printed by the authority of the State of Illinois/2001/10,000

David A. Grimley Barbara. J. S Michael J.

Geologic Road Map of Illinois: