557 
 IL6gui 
 
 1980-D 
 
 uide to the geology 
 of the Quincy North area 
 
 David L Reinertsen 
 
 Commemorating the 50th Field Trip Season and the Survey's 75th year. 
 
Cross section of one of the larger sinkholes 
 exposed along the west siJe of State Route 336 
 at Stop 2. 
 
 Printed by authority of the State of Illinois/1980/500 copies 
 
 l 'L | L 'NO | f STATE GEOLOGICAL SURVEY 
 
 3 3051 00006 8142 
 
A guide to the geology 
 of the Quincy North area 
 
 In 1930 the Geological Survey was 25 years 
 old and the new Educational Extension 
 Section was conducting its first field 
 trips. Dr. M. M. Leighton, the Survey's 
 third Chief, had created the section and 
 its program "...to cooperate with the 
 science teachers of the state and furnish 
 them information regarding geology, such 
 as will be helpful in their teaching of 
 earth history and the development of life.' 
 
 Part of the Section's work was to start a 
 series of six annual "earth history field 
 trips." More than 250 teachers and laymen 
 attended the first year's trips near Dun- 
 dee, La Salle-Starved Rock, Charleston- 
 Mattoon-Ef f i ngham , Harri sburg-Shawneetown , 
 Quincy, and Rock Island. In its 50 years 
 (except for the war years 1942 to 1945), 
 Ed. Extension has conducted more than 290 
 field trips. In 1979, 367 people from all 
 walks of life attended the Survey's four 
 field trips. 
 
 mmm-"* 
 
 ~x~ 
 
 w* 
 
 4 
 
 <#P\* 
 
 0m, 
 
 -M* 
 
 s 
 
 
 
 U / • '« '-^L^<*-^ 
 
 Teachers on the Quincy field trip, October 4, 1930, assemble in a quarry. 
 
Figure 1. Index map with locations of 
 
 (1) Illinois Basin, and 
 
 (2) Mississippi River Arch. 
 
 Chicago 
 
 Rockford 
 
 Figure 2. Stylized north-south cross section shows the structure of the Illinois Basin. In order to 
 show detail, the thickness of the sedimentary rocks has been greatly exaggerated and the 
 younger, unconsolidated surface deposits have been eliminated. The oldest rocks are Pre- 
 cambrian (Pre-C) granites. They form a depression that is filled with layers of sedimentary 
 rocks of various ages: Cambrian (C), Ordovician (0), Silurian (S), Devonian (0), Mississip- 
 pian (M), Pennsyl vanian (P), Cretaceous (K), and Tertiary (T). The scale is approximate. 
 
the geologic framework 
 
 Physiography and geology of the area 
 
 The Quincy North field trip area in western central Illinois was glaciated 
 more than once during the past million years or so. Some of the oldest known 
 glacial deposits, of Nebraskan Age and Kansan Age, have been found in this 
 
 part Of Our State (see Pleistocene glaciations in Illinois at the back of the 
 
 guide leaflet). 
 
 The field trip area lies within the Dissected Till Plains Section of the 
 Central Lowlands Province, an area covered by Nebraskan and Kansan glaciers 
 
 (see map Of the Physiographic divisions of Illinois and the Glacial Map of 
 
 Illinois included at back of guide leaflet). The northeastern part of the 
 field trip area crosses onto the Galesburg Plain of the Till Plains Section, 
 an area covered by Illinoian glaciers. Glacial deposits are exposed best 
 along stream valleys and in new roadcuts. These deposits include pre-Illinoian 
 outwash gravels and tills, Illinoian outwash and loess, and Wisconsinan out- 
 wash and loess. 
 
 The Quincy area can be divided into three areas: (1) the Mississippi River 
 valley, (2) the dissected uplands adjacent to the valley, and (3) the gently 
 rolling to flat upland plains developed on glacial till. Drainage of the area 
 is southwestward to the Mississippi River, which occupies a rock-walled gorge 
 eroded into Mississippian limestones. Glacial drift in the area is thin and 
 tributaries to the Mississippi River have deeply dissected the glacial deposits. 
 The topography is rugged and reflects at least some of the irregularities of 
 the bedrock surface, including sinkholes locally. The rugged topography of 
 the Dissected Till Plains Section contrasts markedly with the younger, more 
 even, and relatively less dissected Illinoian till plain (Galesburg Plain) 
 some 20 miles to the east except in the northeastern part of the field trip 
 area. Wind-blown loess (pronounced "luss") blankets the ground surface through- 
 out the area. 
 
 Bedrock exposed in the field trip area consists of Mississippian limestone, 
 shale, and siltstone of the Valmeyeran Series deposited nearly 335 million 
 years ago. Limestone is the predominant rock in this area and is the basis 
 of an active quarrying industry. These limestones are well exposed along the 
 Mississippi River bluff in this area, which marks the northwestern margin of 
 the Illinois Basin— a large, spoon-shaped, bedrock structure covering most 
 of Illinois and adjacent parts of Indiana and Kentucky (fig. 1). Quincy is 
 located along the crest of the broad Mississippi River Arch from which the 
 bedrock dips gently southeastward into the deepest part of the Illinois 
 Basin (figs. 1 and 2). While this basin was slowly subsiding during the 
 
CRETACEOUS AND PLEISTOCENE IN WESTERN ILLINOIS 
 
 R 3 W 
 
 Revised boundary of lllinoion 
 qlociation 
 ( Kansan till to the west ) 
 
 Scale of Miles 
 
 5 
 
 i i i — i t 
 
 10 
 
 Figure 3. Map showing the distribution of the 3aylis Formation of Cretaceous age in western 
 Illinois, the boundary of Illinoian glaciation, and the locations of samples and 
 geologic sections. 
 
Paleozoic Era, it was gradually filled with Paleozoic sediments that even- 
 tually were altered to bedrock. These strata thicken to more than 13,000 
 feet in the deepest part of the basin, located in extreme southeastern 
 Illinois. Pennsylvanian strata, deposited from 320 to 280 million years ago, 
 are the youngest strata known from the basin and may represent the last of 
 the marine invasions during the Paleozoic Era. On the other hand, marine 
 conditions may have persisted into the Permian Period, which marks the close 
 of the Paleozoic Era, with the sea withdrawing for the last time about 225 
 million years ago. Since then most of the region has been above sea level 
 and exposed to erosion. During this long interval of erosion, all of the 
 Permian strata and a considerable thickness of Pennsylvanian and older strata 
 were removed. Pennsylvanian rocks are exposed just a few miles east of the 
 field trip area. 
 
 In the northern part of the field trip area, Cretaceous sands and gravels are 
 exposed along a topographic high area passing southeastward into Pike County 
 (fig. 3). These deposits are isolated from known Cretaceous sediments about 
 200 miles to the west in Iowa and about 240 miles to the south in extreme 
 southern Illinois. 
 
 Mineral resources 
 
 In 1978, the last year for which totals are available, mineral materials 
 mined in Illinois were worth approximately $1,637,000,000. Stone, sand and 
 gravel, and crude oil are the mineral materials produced in Adams County. 
 In addition, iron oxide pigments are processed here. Adams County ranked 
 39th among the 98 mineral producing and processing counties in 1978, with a 
 value of $8,831,000. 
 
 Sixty Illinois Counties with 271 quarries produced about 62,456,000 tons 
 of crushed stone valued at $160,475,000. Adams County ranked 9th among the 
 Illinois stone-producing counties; 8 quarries produced 955,309 tons valued 
 at $8,208,859. Fifty-nine counties having 197 operations owned by 172 
 companies produced 37,700,000 tons of common sand and gravel valued at 
 $83,694,000. One company produces sand and gravel in Adams County. Less 
 than 3,000 barrels of crude oil were produced from the southeastern part of 
 the county during the year. 
 
H CM GO I I- CO GO 
 
guide to the route 
 
 The field trip begins in the south part of Quincy at the main shelter house 
 of South Park. Mileage figures begin northeast of the shelter house at the 
 intersection of Harrison and South 12th Streets. 
 
 Main Shelter House (SE 1/4 SW 1/4 NE 1/4 
 SE 1/4 Sec. 11, T. 2 S., R. 9 W., 4th P.M. 
 Quincy West 7.5-minute Quadrangle). A 
 little more than 400 feet south is 
 Curtis Creek which has eroded its bed down 
 into the fossiliferous Mississippian 
 Burlington Limestone. 
 
 Miles to 
 
 Miles from 
 
 next point 
 
 starting point 
 
 0.0 
 
 0.0 
 
 1.0 
 
 1.0 
 
 1.0 
 
 2.0 
 
 0.1 
 
 2.1 
 
 1.0 
 
 3.1 
 
 0.5 
 
 3.6 
 
 0.35 
 
 3.95 
 
 0.4 
 
 4.35 
 
 0.25 
 
 4.6 
 
 0.5 
 
 5.1 
 
 CAUTION, leave South Park heading east on 
 Harrison Street. STOP at 12th Street. 
 
 STOP at South 24th Street. CONTINUE AHEAD 
 (east). 
 
 STOP at South 36th Street and State Route 
 (SR) 96. TURN RIGHT (south) and prepare to 
 turn left. 
 
 TURN LEFT (east) on blacktop road (1050 N). 
 
 STOP, 1-way (900 E). TURN RIGHT (south) 
 for 0.5 mile. 
 
 TURN LEFT (east) on gravel road (1000 N). 
 
 CAUTION, narrow bridge. 
 
 Cross SR-336 overpass. 
 
 TURN RIGHT (south) past St. Anthony's Church. 
 
 To the LEFT note the large slump block that 
 has slid down and rotated toward the creek. 
 Note how the trees have been skewed. CONTINUE 
 AHEAD and cross creek. 
 
\ 
 
 / 
 
 \ \ 
 
 / 
 
 / 
 
 y 
 
 / 
 
 / 
 
 / \ 
 
 y 
 
 \ N 
 
 / 
 
 \ / 
 
 \S\\S\\\W 
 
 Peoria Loess— loess, silt 
 loam, light yellowish 
 brown; leached. 
 
 Unnamed unit— pedisedi- 
 ments, silt loam, 
 leached; contains 
 pebble layers; underlain 
 by a stone line, 
 
 Wolf Creek Formation 
 Hickory Hills Till Member 
 Till, loam, yellowish 
 brown (10YR 5/6), 
 leached; contains trun- 
 ^_ cated Yarmouth Soil 
 
 Aurora Till Member 
 
 Till, loam, indistinct 
 color zonations, colors 
 ranging from pale olive 
 (5Y 6/3) to yellowish 
 brown (10YR 5/4); 
 leached; highly jointed; 
 contains block inclu- 
 sion of lower peaty 
 silt and alluvium at 
 10 m; lower part of 
 till contains abundant 
 wood. 
 
 (m) (ft) 
 5n 
 
 -15 
 
 4- 
 
 3--10 
 
 2- 
 
 l- 
 
 0-1-0 
 
 "5 
 
 / Unnamed unit 
 
 Peaty silt, dark brown; 
 contains wood and 
 other organic material. 
 
 Alluvium (?), silt loam, 
 gray, leached; contains 
 abundant wood and 
 chert pebbles; contains 
 lenses of chert gravels. 
 
 ISGS 1979 
 
 < 
 
 z 
 < 
 
 z 
 
 Z 
 
 o 
 o 
 
 oo 
 
 Figure 4. Stop 1. Mill Creek Section. 
 
0.4 5.5 Cross creek. Note weathered Burlington 
 
 Limestone exposed in the roadcut to the right, 
 
 0.1 5.6 To the RIGHT, just west of the fence corner 
 
 with the "KEEP OUT" sign, is Wand Spring 
 flowing out from the Burlington Limestone. 
 Watercress formerly was raised here as a 
 cash crop for the local market. CONTINUE 
 AHEAD (south). 
 
 0.75 6.35 CAUTION. Pull off the road on the right 
 
 shoulder south of Halfpap's Mobile Home Park. 
 Do NOT block the driveway. Use CAUTION in 
 crossing the road to the south side. The 
 exposure is on the south side of Mill Creek 
 about 300 feet south of the Mobile Home Park 
 entrance. 
 
 STOP Pleistocene deposits of the Mill Creek 
 
 m Section (SW 1/4 NW 1/4 SW 1/4 Sec. 22, 
 
 T. 2 S., R. 8 W., 4th P.M. Quincy East 
 7.5-minute Quadrangle). 
 
 The following discussion is adapted from J. T. Wickham (1979). 
 
 The large exposures of Pleistocene deposits that occur along Mill Creek are 
 
 subject to frequent large-scale slumping. The lower part of the section 
 
 exposed here is unstable and different parts of the exposure have periodically 
 been exposed and then later slumped over (fig. 4). 
 
 Although this is one of the larger Pleistocene sections exposed in this area, 
 it does not have all of the stratigraphic elements present. Several units 
 are missing from the upper part of this section. Slightly less than 8 feet 
 of Peoria Loess are exposed at the top of the bluff. Found locally beneath 
 the loess is a zone of material (pedisediments) deposited on the underlying 
 erosion surface during the slope-forming process. The Peoria Loess and locally 
 the pedisediments occur above a stone line that represents an erosion surface. 
 Although the exact date of the erosion cycle represented cannot be determined, 
 an approximate age is possible. In this part of Illinois, the Illinoian 
 Loveland Silt, Sangamon Soil, and Wisconsinan Roxana Silt occur between the 
 Peoria Loess and the underlying Pre-Illinoian deposits. Since these units 
 are missing here, the erosion cycle must have taken place sometime after the 
 Roxana Silt was deposited and before the Peoria Loess was deposited. Roxana 
 deposition appears to have ceased about 30,000 radiocarbon years B.P. (before 
 present) (McKay, 1979). In the upper Mississippi Valley region the Peoria 
 Loess was deposited between about 20,000 and 13,000 radiocarbon years B.P. 
 The erosion cycle, therefore, must have occurred sometime between approximately 
 30,000 and 20,000 radiocarbon years B.P. 
 
 It appears that part of the underlying Pre-Illinoian Wolf Creek Formation was 
 eroded in the erosion cycle mentioned above. The uppermost Hickory Hills 
 
Till Member is quite thin here when compared with other sections nearby. A 
 Yarmouth Soil profile was developed down through the Hickory Hills Till Member 
 into the underlying Aurora Till Member. The Hickory Hills is more sandy than 
 the Aurora, which is quite silty; the Aurora is also more gray than the 
 Hickory Hills. 
 
 Beneath the Wolf Creek Formation is a complex zone of organic silts that may 
 be nearly 10 feet thick. Underlying the organic silts is a leached silty loam 
 that extends to the creek bed where the Mississippi an Burlington Limestone is 
 exposed. The loam is a poorly sorted material thought to be alluvium, although 
 it resembles glacial till. Occasional igneous pebbles, considerable wood 
 debris, and much chert is present in this deposit. Isolated chert pebble and 
 cobble bodies resemble gravel bars, suggesting that the material was deposited 
 by a stream. 
 
 Another gap in the geologic record is apparent when the lower part of this 
 exposure is examined. The oldest unconsolidated deposits here, probably less 
 than a million years old, were deposited when the region stood well above 
 sea level; however, the underlying Burlington Limestone was deposited in a 
 warm, shallow sea that covered the Midcontinent Region during the Mississippian 
 Period, some 340-335 million years ago. As mentioned previously, an unknown 
 thickness of younger Mississippian, Pennsylvanian, perhaps Permian, and 
 Cretaceous sediments was eroded away before the first glaciers slowly flowed 
 across the region more than a million years ago. 
 
 Miles to Miles from 
 next point starting point 
 
 0.0 6.35 Leave Stop 1. CONTINUE AHEAD (west). 
 
 0.4 6.75 STOP. TURN RIGHT (north) onto SR 96 and 
 
 prepare to turn right again. 
 
 0.1 6.85 TURN RIGHT (easterly) on approach to SR 336. 
 
 0.3 7.15 CAUTION. Enter SR 336 and move to the 
 
 inside (left) lane as soon as possible. 
 
 0.3 7.45 Prepare to turn left. 
 
 0.2 7.65 CAUTION. TURN LEFT (west) at gravel cross- 
 
 over to southbound lanes. NOTE: keep in 
 LEFT lane on the gravel cross-over and TURN 
 LEFT (south) on to the blacktop emergency 
 parking strip. PARK as close to the edge of 
 the parking strip as possible; leave your 
 vehicle ONLY on the DRIVER'S SIDE. CAUTION: 
 Cross to the west side of the highway and 
 walk north about 400 feet to the exposure. 
 
 10 
 
STOP Glacial deposits and sinkholes in SR 336 
 
 rri roadcut (SE 1/4 SE 1/4 SE 1/4 Sec. 16, 
 
 LfJ T. 2 S., R. 8 W., 4th P.M. Quincy East 
 
 7.5-minute Quadrangle). The following 
 discussion is adapted from the Wand Spring 
 Section of J. T. Wickham (1979). 
 
 This roadcut through the Burlington Limestone shows the solution effects of 
 percolating groundwater on jointed, soluble bedrock strata covered by glacial 
 deposits and soil layers (fig. 5). The larger sinkholes and open joints are 
 filled with dark red clay and chert residuum, characteristic residual deposits 
 left behind from intense chemical weathering of a cherty limestone. Sand is 
 also present in some of the fillings. None of these materials occurs above 
 the bedrock surface here, indicating that they were in place before glaciation 
 and that the glaciers did not excavate the small sinkhole depressions to 
 remove these deposits. Instead, some of the sinkholes are partially blocked 
 at the top by jumbled bedrock blocks. Some of the blocks may have been ripped 
 from the bedrock surface by the overriding glaciers and then smeared into the 
 sinkholes. 
 
 Do you suppose that surface water percolating downward through these glacial 
 deposits and moving downward and laterally through the Burlington Limestone 
 might be coming out of the hillside at Wand Spring a little more than 0.15 
 miles east-southeast of this locality? Would you expect this water to have 
 been filtered much in passing through this bedrock unit? Why? 
 
 Glacial deposits near the north end of the roadcut truncate the upper part of 
 the bedrock (fig. 5). Part of the section shown in figure 6 is within the 
 large sinkhole extending downward from this till section. The Pleistocene 
 deposits here are correlated with the Aurora Till Member of the Pre-Illinoian 
 Wolf Creek Formation also observed at Stop 1. 
 
 Miles to Miles from 
 next point starting point 
 
 0.0 7.65 Leave Stop 2. CAUTION: CONTINUE AHEAD 
 
 (southerly) and move into the outside (right) 
 lane as soon as possible. 
 
 0.4 8.05 BEAR RIGHT (westerly) at exit ramp from 
 
 SR 336 toward SR 96. 
 
 STOP. TURN LEFT (south) on SR 96. 
 
 Cross SR 336 overpass and CONTINUE AHEAD 
 (south). 
 
 Cross Mill Creek. 
 
 Cross Burton Creek. Burlington Limestone is 
 exposed to the left in the creek. 
 
 0.4 
 
 8.45 
 
 0.1 
 
 8.55 
 
 0.25 
 
 8.8 
 
 1.15 
 
 9.95 
 
 11 
 
(m) (ft) 
 20-i 
 
 10- 
 
 50 m 
 
 50 100 150 ft 
 
 ISGS 1979 
 
 Figure 5. Diagram of Wand Spring Section. Datum is road level. 
 
 J covered 
 
 
 
 ^^^^^ ■ ■■ ■ ■ " ' 'i i 
 
 /v^oV^T 
 
 
 
 /\ N/ *N 
 
 
 
 Wolf Creek Formation 
 
 
 /\/ / / / / 
 
 I , / ^ / / v o 
 
 / ' N N * y / 
 
 Aurora Till Member 
 
 
 Till, loam, light olive brown (2.5Y 5/4) to yellowish brown (10YR 5/4); 
 
 
 calcareous; jointed with reduced zones down the joints; contains calcium 
 
 UJ 
 
 carbonate nodules; has a higher mositure content at the base. 
 
 < 
 
 t- 
 </) 
 
 z 
 
 
 < 
 o 
 
 y .o \ / n o 
 
 
 z 
 
 -J 
 _l 
 
 UJ 
 
 or. 
 
 
 ^ Calcium carbonate ledge, consolidated zone in base of til| 
 
 ^— ■"" " — 7"~'"T* — r"*~* • ~~. ■ • ; 
 
 Iron oxide cemented sand; coarse sand, granules; some angular chert fraa- 
 
 /•••.;. • • .• ...'.• . 
 
 \ ments; very sharp upper contact, uneven lower contact grades into coarse to 
 
 Q- 
 
 /.•••..... - # . . .• . 
 
 \ medium iron-stained sand. 
 
 
 /•♦• ••♦ •• • . . • 
 ■ •••*••* ** 
 
 Sand, coarse, iron-stained, calcareous; some bedding; small amount of fine 
 
 
 material. 
 
 
 
 (m) (ft) 
 
 
 
 2- 
 
 -5 
 
 
 
 1- 
 
 
 
 1 slump 
 
 
 
 
 
 0- 
 
 -0 
 
 
 
 ISGS 1979 
 
 
 Figure 6. Stop 7. Wand Spring Section. 
 
 12 
 
1.2 11.15 Prepare to turn right. 
 
 0.2 11.35 TURN RIGHT (south) on the gravel road across 
 
 from the Haunted Tavern. 
 
 1.1 12.45 STOP at crossroads. Slightly to the left 
 
 the higher part of the Kansan till plain 
 extends more than 2 miles southeast to Payson, 
 TURN RIGHT and head west for 2.5 miles. 
 
 2.0 14.45 Panoramic view to left (south) and straight 
 
 ahead (west) toward the Mississippi River 
 valley. View from the partially dissected 
 Kansan till plains down across the rugged 
 dissected till plains to the river valley. 
 
 0.35 14.8 Park to the right as far as possible without 
 
 getting in the ditch. 
 
 STOP Sinkhole to the right (north). (SE 1/4 
 
 SW 1/4 NW 1/4 Sec. 4, T. 3 S., R. 8 W. , 
 4th P.M. Marblehead 7.5-minute Quadrangle) 
 
 m 
 
 On the uplands in this vicinity there are several circular depressions called 
 sinkholes. To the right about 500 feet is a large sinkhole that frequently 
 has water standing in the bottom. We will pass several others in a short 
 while after we leave this stop. 
 
 A landscape with numerous sinkholes is known as karst topography. Sinkholes 
 develop in regions that are underlain by thick, highly jointed limestone. 
 Downward percolating rainwater takes up organic acids from the soils, enters 
 the joints, and dissolves the limestone. As time passes, underground drainage 
 increases, and a network of subterranean channels and caverns is formed. 
 Sinkholes are formed both by surface solution and by collapse of the roofs of 
 near-surface caverns. 
 
 Four conditions contribute to the development of karst topography. (1) There 
 must be at or near the surface a soluble rock, such as limestone, and the 
 limestone should be flat-lying or nearly so. (2) The limestone should be 
 dense, highly jointed, and preferably thinly bedded. The limestone should not 
 be porous, because under such conditions the rainwater would be absorbed and 
 move through the whole body of the rock, rather than be concentrated along 
 joints and bedding planes to form channels and caverns. These first two 
 conditions are satisfied by the Mississippian limestone strata underlying the 
 uplands in the Quincy area. (3) There must be entrenched major stream valleys 
 below the uplands. These valleys act as outlets toward which the ground water 
 can move in the subsurface. The Mississippi River satisfies this condition. 
 (4) There must be ample rainfall. 
 
 13 
 
Miles to Miles from 
 next point starting point 
 
 0.0 14.8 Leave Stop 3. CONTINUE AHEAD (west) and 
 
 prepare to turn right. 
 
 0.15 14.95 TURN RIGHT (north) at crossroads (903 E). 
 
 0.2 15.15 The depression to the north of the farmhouse 
 
 on the right was a waterfilled sinkhole until 
 a ditch was dug into it to drain it. 
 
 0.1 15.25 North of the house on the left is a water- 
 
 filled sinkhole. 
 
 1.2 16.45 To the right is a low terrace in the field. 
 
 0.45 16.9 CAUTION. One-lane bridge across Burton Creek, 
 
 0.1 17.0 You are crossing the terrace level noted 
 
 previously. 
 
 0.05 17.05 T-road from right. CONTINUE STRAIGHT AHEAD 
 
 (north) . 
 
 0.05 17.1 The low mound to the right in the field is a 
 
 sand dune. 
 
 0.1 17.2 CAUTION. Cross Mill Creek on one-lane bridge, 
 
 0.3 17.5 T-road from left. TURN LEFT (west) on 800 N 
 
 across from the Country Store. On the 
 northwest side of the intersection and about 
 100 feet west of the road is Cole Spring on 
 the west side of the creek. 
 
 0.85 18.35 STOP. TURN LEFT (south) on blacktop. 
 
 1.05 19.4 On the right overgrazing has ruined the sod 
 
 cover, facilitating rapid gullying of the 
 slope. 
 
 0.4 19.8 Crossroad. TURN LEFT (south) on gravel road. 
 
 1.3 21.1 Park on west side of road close to the ditch 
 
 across from the entrance gate of Adams Stone 
 and Materials Company. Walk to the office to 
 get permission for entering this property. 
 CAUTION in crossing the one-lane bridge. 
 
 STOP Quarry in Mississippian Burlington Limestone 
 
 (S 1/2 SE 1/4 SE 1/4 Sec. 31, T. 2 S. , 
 R. 8 W., 4th P.M. Marblehead 7.5-minute 
 Quadrangle) . 
 
 m 
 
 14 
 
Marblehead Lime Company opened this quarry in the 1880s and operated it until 
 1920. Much of its production was from adits driven back into the hillside 
 in the high purity "Quincy Lime." Portions of several of these old adits are 
 now used for storage and shop facilities by the present owners. In the late 
 1920s and early 1930s the former owners sank a shaft down through the under- 
 lying Hannibal Shale into the Louisiana Limestone and used this stone for the 
 manufacture of rock wool for a short time. Much of the stone used in the 
 construction of Lock and Dam 21 at Quincy came from this quarry. The quarry 
 was dormant from the late 1930s until 1975 when Adams Stone and Materials 
 Company purchased the property and reopened the quarry. 
 
 The Burlington Limestone is composed of massive- to thick-bedded, coarse- 
 to medium-grained, highly fossil iferous limestone which generally is more than 
 80 feet thick in the subsurface throughout this area. The top 20 to 40 feet 
 (coarse-grained, wery fossil iferous, glauconitic, and slightly cherty) is 
 called the Cedar Fork Member. The middle 30 to 50 feet, a medium-grained lime- 
 stone locally interbedded with dolomitic limestone and thin shale partings, 
 contains some glauconite and some chert nodules and beds. This limestone is 
 called the Haight Creek Member. The lower part of the Burlington (the Dolbee 
 Creek Member) is an exceptionally pure, white, coarse-grained, thick- to 
 massive-bedded, stylolitic limestone 10 to 40 feet thick containing chert 
 beds and nodules, especially in the upper part. The "Quincy Lime" is contained 
 in the Dolbee Creek Member. 
 
 About 60 feet of the Burlington is exposed in this quarry. The upper 25 to 
 30 feet has a high chert content and is used mainly for the base course in road 
 construction. The less cherty parts of the quarry are used for agstone and for 
 construction aggregates. Crinoid and brachiopod remains are common in the lime- 
 stone here. 
 
 Miles to 
 
 Mi 
 
 les from 
 
 next point 
 
 starting point 
 
 0.0 
 
 
 21.1 
 
 0.5 
 
 
 21.6 
 
 0.05 
 
 
 21.65 
 
 Leave Stop 4. CONTINUE AHEAD (south and west). 
 
 STOP. TURN LEFT (northerly) on SR 57. 
 
 Burlington Limestone containing pronounced 
 chert masses is exposed to the right. 
 
 3.1 24.75 CAUTION. Enter underground mine area of Calcium 
 
 Carbonate Company, Plant No. 3. Note adits into 
 the Burlington Limestone in the bluff to the 
 right. 
 
 0.55 25.3 CAUTION. Railroad crossing. CONTINUE AHEAD 
 
 (north) and prepare to turn right. 
 
 0.15 25.45 CAUTION. BEAR RIGHT (northerly). 
 
 0.05 25.5 PARK to the left close to the north entrance 
 
 to SR 57 from the Underground Warehouse area. 
 
 ' u 'N0iS STATE 
 VOLQGtCM SURVEY 15 
 
 UBRW 
 
ST0P Storage facilities of Underground Warehouse, 
 
 fcl Inc. (NE 1/4 NW 1/4 NE 1/4 Sec. 23, 
 
 Lil T. 2 S., R. 9 W., 4th P.M. Quincy West 
 
 7.5-minute Quadrangle). NOTE: We will not 
 enter the facilities here. BE ALERT for 
 traffic moving in and out of this facility. 
 
 Calcium Carbonate Company, a division of the Huber Corporation, started 
 operations here in 1918. The adits into the bluff on the east side of the 
 Mississippi Valley open into four different quarries owned and operated by 
 this company. Three of the quarries are connected underground so that it is 
 possible to travel about a mile from north to south in the mine. The works 
 extend about 1/4 mile back into the bluff from the face. The lower, more 
 pure Dolbee Creek Member ("Quincy Lime") of the Burlington Limestone is mined 
 in this vicinity. The mined portion here is 28 feet thick and the quarries 
 have a "soapstone" floor, the Hannibal Shale. Temperature in the mines is a 
 constant 60°F. 
 
 This high purity limestone is used in the manufacture of rubber, putty, 
 plasterboard (drywall), paint, plastics, floor tile, animal feed supplements 
 and blacktop for roads. As much as 30 carloads a week are used for the 
 white filler in the manufacture of floor tiles. 
 
 The Underground Warehouse, opened in 1969, is the only facility of its kind in 
 Illinois at the present, and is an excellent example of sequential land use. 
 There are actually six separate warehouses here that extend back about 1/4 
 mile from the bluff face. One room has an area of 5.25 acres. The warehouse 
 is served by two railroad tracks and also has facilities for handling trucks. 
 Commodities stored here include beer, musical organs, sugar, air filters, 
 thermos equipment and products, and tires. The constant temperature and 
 humidity are ideal for storing these products. 
 
 Miles to Miles from 
 next point starting point 
 
 0.0 25.5 STOP. BEAR RIGHT (northerly) on SR 57. 
 
 1.7 27.2 Intersection with Jackson Street. The 
 
 building to the right on the northeast 
 corner of the intersection is constructed 
 of native stone from this area. It is owned 
 by the Sass Brothers Pattern Shop, Inc. 
 CONTINUE AHEAD (north) and prepare to turn 
 left. 
 
 0.35 27.55 STOPLIGHT at Jefferson Street. CAUTION. 
 
 TURN LEFT (west) and cross two railroad 
 tracks. 
 
 0.05 27.6 STOP. TURN RIGHT (north) on Great River 
 
 Road. CAUTION. This is an industrial area. 
 
 16 
 
0.15 27.75 Slightly to the right (north-northeast) on 
 
 the bluff is a mosque-type structure, the 
 Villa Katherine, now abandoned but located 
 in a park of the same name. 
 
 0.6 28.35 Go under the Mississippi River highway bridge, 
 
 0.25 28.6 STOP. The Quincy Sand Company is located 
 
 to the left at the foot of Broadway. This 
 company uses a dredge to win sand from river 
 bars; the material is sized on the dredge 
 and then loaded on to an accompanying 
 barge. The over- and under-sized material 
 is discharged into the river. The barge is 
 towed in to the loading facility here, where 
 it is loaded into the overhead hoppers for 
 easy truck loading. TURN RIGHT (east) on 
 Broadway and ascend the hill to just beyond 
 the Burlington Northern (BN) Railroad 
 trestle. 
 
 0.1 28.7 TURN LEFT (north) on North 2nd Street. 
 
 0.5 29.2 TURN LEFT (west) at Chestnut Street 
 
 entrance to Riverview Park and BEAR RIGHT. 
 
 0.05 29.25 Memorial statue of General George Rogers 
 
 Clark on the right. CONTINUE AHEAD (west 
 and north) . 
 
 0.1 29.35 PARK along curb. LUNCH. After lunch 
 
 assemble at the overlook on the west side 
 of the street. 
 
 STOP Overview and discussion of the Mississippi 
 
 River Valley (Near C W 1/2 SW 1/4 SW 1/4 
 NW 1/4 Sec. 35, T. 1 S., R. 9 W., 4th P.M. 
 Quincy West 7.5-minute Quadrangle). 
 
 m 
 
 The Mississippi River Valley, the most prominent topographic feature in the 
 field trip area, is approximately 6 miles wide. The bedrock floor of the 
 valley is less than 300 feet mean sea level (m.s.l.) while the 
 surface of the floodplain here is about 470 feet m.s.l. There is, therefore, 
 a considerable amount of valley fill in this vicinity. 
 
 The Mississippi River we see today south of the Rock Island area generally 
 follows a large preglacial valley southward to its juncture with the pre- 
 sent Illinois River. Prior to the diversion during Wisconsinan time, this 
 large valley was occupied by the preglacial Iowa River, which appears to have 
 headed in southern Minnesota and flowed southward across eastern Iowa to 
 Muscatine, where it turned southward. The Ancient Mississippi River, on the 
 
 17 
 
ISGS 1980 
 
 18 
 
other hand, followed its present course ilong what is now northwestern 
 Illinois to the vicinity of Fulton, whet \ it swung southeastward toward 
 Princeton and the present "Big Bend" of he Illinois River. From the Big 
 Bend southward, the Ancient Mississippi ;ssentially followed the present 
 Illinois River course to Calhoun County vhere it was joined by the preglacial 
 Iowa River. 
 
 The valley is entrenched 200 to 500 feel below the adjacent bedrock uplands, 
 here largely into fairly resistant Mississippian limestone strata which have 
 helped to maintain a relatively narrow, ;teep-walled configuration. 
 
 Although both the preglacial Iowa River md the Ancient Mississippi River 
 may have formed before glacial times, th»n'r valleys were deepened and widened 
 by meltwaters from the Nebraskan and Kansan glaciers. Deposits attributable 
 to these periods of glaciation have been found in the deeper parts of the 
 bedrock valleys. During the Illinoian glaciation, the preglacial Iowa River 
 was again forced from its valley to a westerly course in Iowa. However, this 
 Illinoian diversion was only temporary, and when the ice had melted away the 
 river resumed its older southward course. Tremendous volumes of meltwater 
 from the receding Illinoian glacier and the later Wisconsinan glaciers 
 removed any Illinoian glacial deposits that were in the valley. During the 
 Woodfordian advance of the Wisconsinan glaciation (note small maps in the 
 attached Pleistocene giaciations in Illinois), the Ancient Mississippi River 
 was forced westward and permanently diverted into the preglacial Iowa Valley 
 when meltwater over-topped a bedrock divide at Cordova in Rock Island County. 
 The Ancient Mississippi Valley to the Big Bend was buried by drift and 
 permanently abandoned. The Illinois River then assumed the valley of the 
 Ancient Mississippi southward to southern Calhoun County. 
 
 Miles to Miles from 
 next point starting point 
 
 0.0 29.35 Leave Stop 6. CONTINUE AHEAD (north). 
 
 0.05 29.4 BEAR LEFT (northerly) down the hill. 
 
 0.1 29.5 The slumped loess to the right over the 
 
 stone retaining wall is the result of 
 children's digging in it farther up the 
 slope. 
 
 STOP. TURN LEFT (west) on Cedar Street. 
 
 STOP just beyond BNRR overpass. TURN 
 RIGHT (north) on the Great River Road. 
 
 CAUTION. Guarded BNRR crossing. 
 
 BNRR trestle above. CAUTION. Road is wavy 
 ahead. 
 
 0.1 
 
 29.6 
 
 0.2 
 
 29.8 
 
 0.15 
 
 29.95 
 
 0.35 
 
 30.3 
 
 19 
 
0.2 
 0.35 
 
 0.15 
 
 0.35 
 1.0 
 
 0.2 
 
 30.5 
 30.85 
 
 31.0 
 
 31.35 
 32.35 
 
 32.55 
 
 CAUTION. Jog right and then left across 
 unguarded BNRR crossing. 
 
 Abandoned quarry and cave adits in the 
 Burlington Limestone to the right in Lenane 
 Park. 
 
 TURN RIGHT (east) and ascend hill on Bluff 
 Road (1400 N). 
 
 STOP. TURN LEFT (north) on North 5th Street, 
 
 STOP. TURN LEFT (west) on 1500 N. Prepare 
 to stop near the crest of the bluff. 
 
 PARK to the right as far as possible so that 
 you have to get out on the driver's side. 
 
 STOP 
 
 m 
 
 North Quincy loess section (NW 1/4 NE 1/4 
 NW 1/4 Sec. 23, T. 1 S. , R. 9 W. , 4th P.M. 
 Quincy West 7.5-minute Quadrangle). 
 
 NORTH QUINCY SECTION 
 
 Measured in roadcuts in NW 1/4 NE 1/4 NW 1/4 Sec. 23, 
 T. 1 S., R. 9 W., Adams County, Illinois, 1961. 
 
 Pleistocene Series Thickness 
 
 Wisconsinan Stage (feet) 
 
 Woodfordian Substage 
 Peoria Loess - surface soil developed in top; 
 loess below is yellow- tan, coarse, 
 calcareous, massive, friable, and 
 contains occasional fossils; becomes 
 clayey and mottled gray and tan with 
 brown spots in lower 9 feet. 37.0 
 
 Altonian Substage 
 Roxana Silt - silt with some clay, purplish 
 brown to tan-brown with slight 
 pinkish cast in lower part, non- 
 calcareous; becomes sandy and 
 massive downward and contains 
 some angular chert fragments. 4.0 
 
 Sangamonian Stage 
 
 111 inoian Stage 
 
 Sangamon Soil developed in sand and gravel, 
 dark red with some gray and brown 
 mottling, clayey, locally 
 cemented; covered in lower part. 15.0 
 
 56.0 
 
 20 
 
Miles to Miles from 
 next point starting point 
 
 0.95 
 
 36.4 
 
 0.05 
 
 36.45 
 
 0.2 
 
 36.65 
 
 0.0 32.55 Leave Stop 7. CONTINUE AHEAD (west). 
 
 0.05 32.6 STOP. TURN RIGHT (north) at foot of bluff. 
 
 1.3 33.9 Cross Homan Creek. Note alluvial deposits 
 
 in the creek bank to the right. 
 
 1.55 35.45 Very cherty Keokuk Limestone that overlies 
 
 the Burlington Limestone in roadcut to 
 right. 
 
 Cross bridge and prepare to turn right. 
 
 TURN RIGHT (east) on gravel road (1850 N). 
 
 CAUTION. Sharp S-curve across narrow 
 concrete bridge. 
 
 0.35 37.0 View to left of cascade over limestone out- 
 
 crop in pasture. 
 
 Undercut limestone ledge to left. 
 
 STOP at SR 96. CONTINUE STRAIGHT AHEAD 
 (east). 
 
 CAUTION. Narrow concrete bridge. 
 
 TURN RIGHT (east) on 1903 N. 
 
 Gravels exposed in the ditches here are 
 Kansan in age and probably are reworked 
 Cretaceous gravels. 
 
 Occasional banded quartzite cobbles can 
 be found along with abundant chert; 
 occasional geodes i frequent siliceous 
 masses that look somewhat like geodes 
 correlated with certain fossil types, and 
 occasional granite and other igneous rocks. 
 
 0.05 40.75 CAUTION. Narrow iron bridge over Rock 
 
 Creek. 
 
 0.5 41.25 Small draw to the left (north) along the 
 
 south edge of the feedlot shows Warsaw Shale 
 containing geodes overlain by gravel, some 
 of which may be reworked Cretaceous material, 
 
 0.1 
 
 37.1 
 
 1.05 
 
 38.15 
 
 1.7 
 
 39.85 
 
 0.2 
 
 40.05 
 
 0.65 
 
 40.7 
 
 21 
 
R9W 
 
 R8W 
 
 22 
 
0.05 41.3 CAUTION. Crossroads. TURN LEFT (north) 
 
 on 1000 E. 
 
 0.6 41.9 Cross Sand Branch. 
 
 0.25 42.15 Warsaw limestone exposed in cut bank to 
 
 right. Overlain by chert gravels. No 
 igneous materials noted. May be Cretaceous 
 gravels. 
 
 CAUTION. Narrow concrete bridge. 
 
 CAUTION. Narrow iron bridge. About 3 feet 
 of gray Warsaw Shale is exposed in the 
 creek on the right (east) side of the bridge, 
 
 STOP at SR 61. TURN RIGHT (east) and pre- 
 pare to turn left. 
 
 TURN LEFT (north) on gravel road and 
 immediately cross unguarded BNRR crossing. 
 
 TURN RIGHT (east). 
 
 TURN LEFT (north). 
 
 Jog left and then right at 2400 N. 
 
 PARK to right; do not block driveway. 
 
 STOP Abandoned quarry in limestone and shale of 
 
 •— I the Warsaw. (N 1/2 SW 1/4 NW 1/4 Sec. 27, 
 
 181 T. 2 N., R. 8 W., 4th P.M. Mendon 15-minute 
 
 Quadrangle). You MUST have permission to 
 enter this area. Walk west down the lane 
 to the quarry on the south side of Grind- 
 stone Creek. 
 
 The quarry face exposes about 30 feet of cherty and shaly limestone of the 
 Warsaw. From the quarry floor to the creek, about 4 feet, the shaly lime- 
 stone is interbedded with purer fossil iferous limestone which may constitute 
 a gradation from the Warsaw above to the underlying Keokuk Limestone. 
 
 The quarry floor represents a moment in Mississippian time. It is covered 
 with the shells of the ancient sea life which lived there more than 330 
 million years ago. Several kinds of brachiopods are abundant as are portions 
 of crinoid stems. 
 
 1.8 
 
 43.95 
 
 0.25 
 
 44.2 
 
 0.75 
 
 44.95 
 
 0.05 
 
 45.0 
 
 0.5 
 
 45.5 
 
 0.1 
 
 45.6 
 
 1.0 
 
 46.6 
 
 1.8 
 
 48.4 
 
 23 
 
The Warsaw in western central Illinois and adjacent states is characterized 
 by an abundance of geodes— roughly rounded masses of chalcedony and quartz 
 found throughout the shaly limestone. Many of the geodes are hollow and are 
 lined with crystals of quartz and other minerals. The majority of the geodes 
 here in the quarry are solid chalcedony. Best collecting areas are along 
 Grindstone Creek 1/2 mile above and below the quarry. (NOTE: you MUST 
 obtain permission from the various property owners to collect in those 
 localities too). 
 
 Miles to 
 next point 
 
 Miles from 
 starting point 
 
 0.0 
 0.3 
 
 0.9 
 
 48.4 
 48.7 
 
 49.6 
 
 Leave Stop 8. CONTINUE AHEAD (northeast). 
 
 T-road intersection. TURN LEFT (north) on 
 1350 E and immediately cross narrow 
 concrete bridge over Grindstone Creek. 
 
 Note the gentle walls of the valley into 
 which we are descending. This fairly wide 
 valley has a stream in it too small to have 
 produced this size valley. This may have 
 been a temporary course for Bear Creek at 
 one time. 
 
 0.45 
 
 0.05 
 
 50.05 
 
 50.1 
 
 The north valley wall is steeper than the 
 south. The north slope is supported by 
 bedrock ledges of Mississippian St. Louis 
 Limestone. 
 
 PARK along the east side of the road. Do 
 NOT block the gate to the pig lot. 
 
 STOP 
 
 Discussion of Bear Creek drainage. (NW 1/4 
 SW 1/4 SE 1/4 Sec. 15, T. 2 N., R. 8 W., 
 4th P.M. Mendon 15-minute Quadrangle). 
 
 The St. Louis 
 ledges in the 
 valley remnan 
 gives the val 
 at the same e 
 mouth of Bear 
 time that it 
 several miles 
 
 Limestone, which lies above the Warsaw, is exposed here as low 
 
 road and the barnyard. The view south and east is over an old 
 t without a stream. The rounded contour of the valley walls 
 ley a mature appearance. The valley floor is in rock and lies 
 levation (560 feet m.s.l.) as the terraces to the west at the 
 
 Creek. Bear Creek probably occupied this valley at the same 
 built the flood plain now represented by the terrace remnants 
 
 to the west where it joins the Mississippi Valley. 
 
 Later Bear Creek or a tributary working northward found part of an ancient, 
 preglacial, drift-filled valley in the bedrock. There it was able to erode 
 its channel downward more rapidly, so that in time it abandoned the rock- 
 floored valley to the south. 
 
 24 
 
END OF FIELD TRIP. Have a safe journey home. 
 
 Retrace route to SR 61 west of Mendon (5 miles), or continue ahead (north) 
 for about 1.25 miles to the blacktop; turn left and follow 4 miles to 0.75 
 miles south of Lima, SR 96; or turn right (east) and follow blacktop 5.5 
 miles east and south to Loraine, thence south 1.5 miles to SR 61. 
 
 PROPERTY OWNERS 
 
 Stop 1: Mr. Sieg Halfpap, St. Anthony Road, R. R. 5, Quincy, IL 62301 
 
 Stop 4: Adams Stone and Materials Company, R. R. 5, Quincy, IL 62301 
 
 Stop 5: Underground Warehouse. Calcium Carbonate Company, Front and 8th 
 Streets, Quincy, IL 62301 
 
 Stop 8: Mr. Henry R. Cannell, Mendon, IL 62351 
 BIBLIOGRAPHY 
 
 Collinson, C, 1964, Western Illinois: 28th Annual Tri-State Geological 
 
 Field Conference, Illinois State Geological Survey Guidebook Series 6, 
 30 p. 
 
 Cote, W. E., et al., 1966, Quincy Area: Illinois State Geological Survey 
 guide leaflet 1966-B, 21 p. 
 
 Frye, J. C, H. D. Glass, and H. B. Willman, 1962, Stratigraphy and 
 
 mineralogy of the Wi scons i nan loesses of Illinois: Illinois State 
 Geological Survey Circular 334, 55 p. 
 
 Frye, J. C, H. B. Willman, and H. D. Glass, 1964, Cretaceous deposits and 
 the Illinoian glacial boundary in Western Illinois: Illinois State 
 Geological Survey Circular 364, 28 p. 
 
 Goodwin, J. H., 1979, A Guide to selecting an agricultural limestone product: 
 Illinois State Geological Survey Illinois minerals notes 73, 7 p. 
 
 Goodwin, J. H. , and R. D. Harvey, 1980, Limestone resources of Adams and 
 Brown Counties, Illinois: Illinois State Geological Survey Circular 
 512, 20 p. 
 
 Hayes, J. B., 1964, Geodes and concretions from the Mississippian Warsaw 
 Formation, Keokuk Region, Iowa, Illinois, Missouri: Journal of 
 Sedimentary Petrology, v. 34, no. 1 , p. 123-133. 
 
 Horberg, C. L., 1950, Bedrock topography of Illinois: Illinois State 
 Geological Survey Bulletin 73, 111 p. 
 
 25 
 
Horberg, C. L., 1956, Pleistocene deposits along the Mississippi Valley in 
 central western Illinois: Illinois State Geological Survey Report of 
 Investigations 192, 39 p. 
 
 Lamar, J. E. , et al., 1934, Rock wool from Illinois mineral resources: 
 Illinois State Geological Survey Bulletin 61, 262 p. 
 
 Lamar, J. E., 1967, Handbook on limestone and dolomite for Illinois quarry 
 operators: Illinois State Geological Survey Bulletin 91, 119 p. 
 
 Leighton, M. M. , 1937, The glacial history of the Quincy, Illinois, region: 
 Illinois Academy of Science Transactions (1936), v. 29, no. 2, p. 172-176. 
 
 Leighton, M. M., G. E. Ekblaw, and C. L. Horberg, 1948, Physiographic divisions 
 of Illinois: Illinois State Geological Survey Report of Investigations 
 129, 19 p. 
 
 Lineback, J. A., 1979, The status of the Illinoian glacial stage: Midwest 
 Friends of the Pleistocene 26th Field Conference, Illinois State 
 Geological Survey Guidebook Series 13, p. 69-78. 
 
 McKay, E. D., 1979, Wisconsinan loess stratigraphy of Illinois: Midwest 
 Friends of the Pleistocene 26th Field Conference, Illinois State 
 Geological Survey Guidebook Series 13, p. 95-108. 
 
 Odom, I. E. , et al., 1960, Quincy Area: Illinois State Academy of Science 
 geology and botany field trip: Illinois State Geological Survey Guide 
 Leaflet No. 60, 18 p. 
 
 Piskin, K. , and R. E. Bergstrom, 1975, Glacial drift in Illinois: thickness 
 and character: Illinois State Geological Survey Circular 490, 35 p. 
 
 Raasch, G. 0., 1950, Quincy Area: Illinois State Geological Survey Guide 
 Leaflet 1950-E, 9 p. 
 
 Samson, I., Illinois mineral industry in 1978 and review of preliminary 
 mineral production data for 1979: Illinois State Geological Survey 
 Illinois Minerals Notes (in preparation). 
 
 Wickham, J. T., 1979, Pre-Illinoian till stratigraphy in the Quincy, 
 
 Illinois, area: 43rd Annual Tri-State Geological Field Conference, 
 Illinois State Geological Survey Guidebook Series 14, p. 69-90. 
 
 Willman, H. B., and J. C. Frye, 1970, Pleistocene stratigraphy of 
 Illinois: Illinois State Geological Survey Bulletin 94, 204 p. 
 
 Willman, H. B., et al., 1975, Handbook of Illinois stratigraphy: Illinois 
 State Geological Survey Bulletin 95, 261 p. 
 
 Worthen, A. H., 1870, Geology and paleontology: Adams County: Geological 
 Survey of Illinois, v. IV, p. 43-61. 
 
 26 
 
PLEISTOCENE GLACIATIONS IN ILLINOIS 
 
 Origin of the Glaciers 
 
 During the past million years or so, the period of time called the 
 Pleistocene Epoch, most of the northern hemisphere above the 50th parallel has 
 been repeatedly covered by glacial ice. Ice sheets formed in sub-arctic regions 
 four different times and spread outward until they covered the northern parts 
 of Europe and North America. In North America the four glaciations, in order 
 of occurrence from the oldest to the youngest, are called the Nebraskan, Kansan, 
 Illinoian, and Wisconsinan Stages of the Pleistocene Epoch. The limits and 
 times of the ice movement in Illinois are illustrated in the following pages 
 by several figures. 
 
 The North American ice sheets developed during periods when the mean 
 annual temperature was perhaps 4° to 7° C (7° to 13° F) cooler than it is now 
 and winter snows did not completely melt during the summers. Because the cooler 
 periods lasted tens of thousands of years, thick masses of snow and ice accumu- 
 lated to form glaciers. As the ice thickened, the great weight of the ice and 
 snow caused them to flow outward at their margins, often for hundreds of miles. 
 As the ice sheets expanded, the areas in which snow accumulated probably also 
 increased in extent. 
 
 Tongues of ice, called lobes, flowed southward from the Canadian 
 centers near Hudson Bay and converged in the central lowland between the Appa- 
 lachian and Rocky Mountains. There the glaciers made their farthest advances 
 to the south. The sketch below shows several centers of flow, the general 
 directions of flow from the centers, and the southern extent of glaciation. 
 Because Illinois lies entirely in the central lowland, it has been invaded by 
 glaciers from every center. 
 
 Effects of Glaciation 
 
 Pleistocene glaciers and the waters melting from them changed the 
 landscapes they covered. The glaciers scraped and smeared the landforms they 
 
 overrode, leveling and filling many of the minor 
 valleys and even some of the larger ones. Moving 
 ice carried colossal amounts of rock and earth, 
 for much of what the glaciers wore off the ground 
 was kneaded into the moving ice and carried along, 
 often for hundreds of miles. 
 
 The continual floods released by melting 
 ice entrenched new drainageways , deepened old ones, 
 and then partly refilled both with sediments as 
 great quantities of rock and earth were carried 
 beyond the glacier fronts. According to some 
 estimates, the amount of water drawn from the sea 
 and changed into ice during a glaciation was 
 probably enough to lower sea level more than 300 
 feet below present level. Consequently, the 
 melting of a continental ice sheet provided a 
 tremendous volume of water that eroded and trans- 
 ported sediments. 
 
1. The Region Before Glaciation - Like most of Illinois, the region illustrated is under- 
 lain by almost flat-lying beds of sedimentary rocks — layers of sandstone ( ••••••" ), limestone 
 
 ( ' i ' i " ) , and shale ( ^-— ) . Millions of years of erosion have planed down the bedrock (BR), 
 creating a terrain of low uplands and shallow valleys. A residual soil weathered from local 
 rock debris covers the area but is too thin to be shown in the drawing. The streams illus- 
 trated here flow westward and the one on the right flows into the other at a point beyond 
 the diagram. 
 
 1 . ! i ! ,i ! 5 
 
 ' ' . ■ ' ■ D ^ ■ ■ ■ ' ■ ' ^-r-^r-L-r-^; 
 
 7*77??^ P. 7??= . ! ..' .■■,■,',, ■ - ; .■'. .:. ■'■ ' ~/.. ' . ' . T :i r? 
 
 2. The Glacier Advances Southward - As the glacier (G) spreads out from its snowfield, it 
 scours (SC) the soil and rock surface and quarries (Q)--pushes and plucks up--chunks of bed- 
 rock. These materials are mixed into the ice and make up the glacier's "load." Where 
 roughnesses in the terrain slow or stop flow (P) , the ice "current" slides up over the 
 blocked ice on innumerable shear planes (S). Shearing mixes the load very thoroughly. As 
 the glacier spreads, long cracks called "crevasses" (C) open parallel to the direction of 
 ice flow. The glacier melts as it flows forward, and its meltwater erodes the terrain in 
 front of the ice, deepening (D) some old valleys before the ice covers them. Meltwater 
 washes away some of the load freed by melting and deposits it on the outwash plain (OP). 
 The advancing glacier overrides its outwash and in places scours much of it up again. The 
 glacier may be 5000 or so feet thick , except near its margin. Its ice front advances per- 
 haps as much as a third of a mile per year. 
 
3. The Glacier Deposits an End Moraine - After the glacier advanced across the area, the 
 climate warmed and the ice began to melt as fast as it advanced. The ice front (IP) is now 
 stationary, or fluctuating in a narrow area, and the glacier is depositing an end moraine. 
 
 As the top of the glacier melts, some of the sediment that was mixed in the ice accumu- 
 lates on top of the glacier. Some is carried by meltwater onto the sloping ice front (IP) 
 and out onto the plain beyond. Some of the debris slips down the ice front in a mudflow (PL), 
 Meltwater runs through the ice in a crevasse (C). A superglacial stream (SS) drains the top 
 of the ice, forming an outwash fan (OP). Moving ice has overridden an immobile part of the 
 front on a shear plane (S). All but the top of a block of ice (B) is buried by outwash (0). 
 
 Sediment from the melted ice of the previous advance (figure 2) was left as a till layer 
 (T) , part of which forms the till plain (TP). A shallow, marshy lake (L) fills a low place 
 in the plain. Although largely filled with drift, the valley (V) remained a low spot in the 
 terrain. As soon as its ice cover melted, meltwater drained down the valley, cutting it 
 deeper. Later, outwash partly refilled the valley — the outwash deposit is called a valley 
 train (VT) . Wind blows dust (DT) off the dry floodplain. The dust will form a loess deposit 
 when it settles. 
 
 4. The Region after Glaciation - The climate has warmed even more, the whole ice sheet has 
 melted, and the glaciation has ended. The end moraine (EM) is a low, broad ridge between the 
 outwash plain (OP) and till plains (TP). Run-off from rains cuts stream valleys into its 
 slopes. A stream goes through the end moraine along the channel cut by the meltwater that 
 ran out of the crevasse in the glacier. 
 
 Slopewash and vegetation are filling the shallow lake. The collapse of outwash into the 
 cavity left by the ice block's melting has made a kettle (K) . The outwash that filled a 
 tunnel draining under the glacier is preserved in an esker (E). The hill of outwash left 
 where meltwater dumped sand and gravel into a crevasse or other depression in the glacier or 
 at its edge is a kame (KM). A few feet of loess covers the entire area but cannot be shown 
 at this scale. 
 
TIME TABLE OF PLEISTOCENE GLAC1ATION 
 
 STAGE 
 
 SUBSTAGE 
 
 NATURE OF DEPOSITS 
 
 SPECIAL FEATURES 
 
 HOLOCENE 
 
 Years 
 
 Before Present 
 7,000 — 
 Valderan 
 
 — 11,000 — 
 
 Twocreekan 
 
 — 12,500 — 
 
 WISCONSINAN 
 (4th glacial) 
 
 Woodfordian 
 
 — 22,000 - 
 Farmdalian 
 
 SANGAMONIAN 
 (3rd interglacial) 
 
 ILLINOIAN 
 (3rd glacial) 
 
 YARMOUTHIAN 
 (2nd interglacial) 
 
 KANSAN 
 (2nd glacial) 
 
 AFTONIAN 
 (1st interglacial) 
 
 NEBRASKAN 
 (1st glacial) 
 
 — 28,000 
 
 Altonian 
 75,000 
 
 175,000 
 
 Jubileean 
 
 Monican 
 
 Liman 
 
 300,000 
 600,000 
 700,000 
 
 900,000 
 
 Soil, youthful profile 
 of weathering, lake 
 and river deposits, 
 dunes , peat 
 
 Outwash, lake deposits 
 
 Outwash along 
 
 Mississippi Valley 
 
 Peat and alluvium 
 
 Ice withdrawal, erosion 
 
 Drift, loess, dunes, 
 lake deposits 
 
 Glaciation; building of 
 many moraines as far 
 south as Shelbyville; 
 extensive valley trains, 
 outwash plains, and lakes 
 
 Soil, silt, and peat 
 
 Ice withdrawal, weathering, 
 and erosion 
 
 Drift, loess 
 
 Glaciation in northern 
 Illinois, valley trains 
 along major rivers 
 
 Soil, mature profile 
 of weathering 
 
 Drift, loess 
 Drift, loess 
 Drift, loess 
 
 Glaciers from northeast 
 at maximum reached 
 Mississippi River and 
 nearly to southern tip 
 of Illinois 
 
 Soil, mature profile 
 of weathering 
 
 Drift, loess 
 
 Glaciers from northeast 
 and northwest covered 
 much of state 
 
 Soil, mature profile 
 of weathering 
 
 Drift 
 
 Glaciers from northwest 
 invaded western Illinois 
 
 1,200,000 or more 
 
 (Illinois State Geological Survey, 1973) 
 
SEQUENCE OF GLACIATIONS AND INTERGLACIAL 
 DRAINAGE IN ILLINOIS 
 
 NEBRASKAN 
 inferred glacial limit 
 
 AFTONIAN 
 major drainage 
 
 KANSAN YARMOUTHIAN 
 
 inferred glacial limits major drainage 
 
 LIMAN 
 glacial advance 
 
 MONICAN 
 glacial advance 
 
 JUBILEEAN 
 glacial advance 
 
 SANGAMONIAN 
 major drainage 
 
 ALTONIAN 
 glacial advance 
 
 WOODFORDIAN 
 glaciol advonce 
 
 WOODFORDIAN 
 
 Valparaiso ice and 
 
 Kankakee Flood 
 
 VALDERAN 
 drainage 
 
 (Prom Willman and Prye, "Pleistocene Stratigraphy of Illinois," ISOS Bull. 94, 
 fig. 5. 1970.) 
 
ILLINOIS STATE GEOLOGICAL SURVEY 
 John C.Frye, Chief Urbana, Illinois 61801 
 
 GLACIAL MAP OF ILLINOIS 
 
 H.B. WILLMAN and JOHN C. FRYE Jgjg 
 1970 
 
 Modified from maps by Leverelt (1899), |£-- 
 EKblow (1959), Leighlon ond Brophy (1961) 
 Willman et al.(l967), and others 
 
 EXPLANATION 
 HOLOCENE AND WISCONSINAN 
 
 Alluvium, sand dunes, 
 and gravel terraces 
 
 WISCONSINAN 
 
 Lake deposits 
 
 WOODFORDIAN 
 
 !;■ S;' : : S : :; ■:■'.. 
 
 Moraine 
 
 Front of morainic system 
 
 Groundmoraine 
 
 ALTONIAN 
 
 Till plain 
 
 ILLINOIAN 
 
 Groundmoraine 
 
 KANSAN 
 
 Till plain 
 
 DRIFTLESS 
 
 Modified from Bull- 94. — pi. 2 
 
 Moraine and ridged drift 
 
TILL PLAINS SECTION ! 
 
 PHYSIOGRAPHIC 
 DIVISIONS 
 
 OF 
 ILLINOIS 
 
 Reprinted 1978 
 
 GREAT LAKE 
 
 SECTION 
 
 Ozark Plateaus Province 
 Interior Low Plateaus Province 
 Central Lowland Province 
 Coastal Plain Province 
 
 
 SHAWNEE HILLS 
 SECTION 
 
 ILLINOIS STATE GEOLOGICAL SURVEV 
 
GEOLOGIC MAP 
 
 Pleistocene and 
 Pliocene not shown 
 
 Wjffl TERTIARY 
 
 CRETACEOUS 
 
 PENNSYLVANIAN 
 Bond ond Mottoon Formations 
 Includes narrow belts of 
 older formations along 
 La Salle Anticline 
 
 PENNSYLVANIAN 
 Carbondale and Modesto Formations 
 
 PENNSYLVANIAN 
 Caseyville, Abbott, and Spoon 
 Formations 
 
 MISSISSIPPIAN 
 Includes Devonian in 
 Hardin County 
 
 DEVONIAN 
 Includes Silurian in Douglos, 
 Champaign, and western 
 Rock Island Counties 
 
 SILURIAN 
 Includes Ordovician and Devonian in Calhoun, 
 Greene,and Jersey Counties 
 
 Pp|i ORDOVICIAN 
 I CAMBRIAN 
 
 ^} Des Plaines Disturbance - Ordovician to Pennsylvanian 
 ^-^~ Fault 
 
 i- ■■■■I". 
 
MISSISSIPPIAN DEPOSITION 
 
 (The following quotation is from Report o<l Investigations 216: Classification of 
 Genevievian and Chesterian . . . Rocks of Illinois (1965) by D. H. Swann, pp. 11-16. 
 One figure and short sections of the text are omitted.) 
 
 During the Mississippian Period, the Illinois Basin was a slowly subsiding 
 region with a vague north-south structural axis. It was flanked by structurally 
 neutral regions to the east and west, corresponding to the present Cincinnati and 
 Ozark Arches. These neighboring elements contributed insignificant amounts of sedi- 
 ment to the basin. Instead, the basin was filled by locally precipitated carbonate 
 and by mud and sand eroded from highland areas far to the northeast in the eastern 
 part of the Canadian Shield and perhaps the northeastward extension of the Appala- 
 chians. This sediment was brought to the Illinois region by a major river system, 
 which it will be convenient to call the Michigan River (fig. 4) because it crossed 
 the present state of Michigan from north to south or northeast to southwest.... 
 
 The Michigan River delivered much sediment to the Illinois region during 
 early Mississippian time. However, an advance of the sea midway in the Mississippian 
 Period prevented sand and mud from reaching the area during deposition of the St. 
 Louis Limestone. Genevievian time began with the lowering of sea level and the 
 alternating deposition of shallow-water carbonate and clastic units in a pattern that 
 persisted throughout the rest of the Mississippian. About a fourth of the fill of 
 the basin during the late Mississippian was carbonate, another fourth was sand, and 
 the remainder was mud carried down by the Michigan River. 
 
 Thickness, facies, and crossbedding. . .indicate the existence of a regional 
 slope to the southwest, perpendicular to the prevailing north 65° west trend of the 
 shorelines. The Illinois Basin, although developing structurally during this time, 
 was not an embayment of the interior sea. Indeed, the mouth of the Michigan River 
 generally extended out into the sea as a bird-foot delta, and the shoreline across 
 the basin area may have been convex more often than concave. 
 
 ....The shoreline was not static. Its position oscillated through a range 
 of perhaps 600 to 1000 or more miles. At times it was so far south that land condi- 
 tions existed throughout the present area of the Illinois Basin. At other times it 
 was so far north that there is no suggestion of near-shore environment in the sedi- 
 ments still preserved. This migration of the shoreline and of the accompanying sedi- 
 mentation belts determined the composition and position of Genevievian and Chesterian 
 rock bodies. 
 
 Lateral shifts in the course of the Michigan River also influenced the 
 placement of the rock bodies. At times the river brought its load of sediment to the 
 eastern edge of the basin, at times to the center, and at times to the western edge. 
 This lateral shifting occurred within a range of about 200 miles. The Cincinnati 
 and Ozark areas did not themselves provide sediments, but, rather, the Michigan River 
 tended to avoid those relatively positive areas in favor of the down-warped basin axis 
 
 Sedimentation belts during this time were not symmetrical with respect to 
 the mouth of the Michigan River. They were distorted by the position of the river 
 relative to the Ozark and Cincinnati shoal areas, but of greater importance was sea 
 current or drift to the northwest. This carried off most of the mud contributed by 
 the river, narrowing the shale belt east of the river mouth and broadening it west 
 of the mouth. Facies and isopach maps of individual units show several times as 
 much shale west of the locus of sand deposition as east of it. The facies maps of 
 the entire Chesterian. . .show maximum sandstone deposition in a northeast-southwest 
 
MD - 2 
 
 belt that bisects the basin. The total thickness of limestone is greatest along the 
 southern border of the basin and is relatively constant along that entire border. 
 The proportion of limestone, however, is much higher at the eastern end than along 
 the rest of the southern border, because little mud was carried southeastward against 
 the prevailing sea current. Instead, the mud was carried to the northwest and the 
 highest proportion of shale is found in the northwestern part of the basin. 
 
 Genevievian and Chesterian seas generally extended from the Illinois Basin 
 eastward across the Cincinnati Shoal area and the Appalachian Basin. Little terri- 
 genous sediment reached the Cincinnati Shoal area from either the west or the east, 
 and the section consists of thin limestone units representing all or most of the 
 major cycles. The proportion of inorganically precipitated limestone is relatively 
 high and the waters over the shoal area were commonly hypersaline. . . Erosion of the 
 shoal area at times is indicated by the presence of conodonts eroded from the St. 
 Louis Limestone and redeposited in the lower part of the Gasper Limestone at the 
 southeast corner of the Illinois Basin... 
 
 The shoal area included regions somewhat east of the present Cincinnati 
 axis and extended from Ohio, and probably southeastern Indiana, through central and 
 east-central Kentucky and Tennessee into Alabama.... 
 
 Toward the west, the seaway was commonly continuous between the Illinois 
 Basin and central Iowa, although only the record of Genevievian and earliest Ches- 
 terian is still preserved. The seas generally extended from the Illinois and Black 
 Warrior regions into the Arkansas Valley region, and the presence of Chesterian out- 
 liers high in the Ozarks indicates that at times the Ozark area was covered. Althougl 
 the sea was continuous into the Ouachita region, detailed correlation of the Illinois 
 sediments with the geosynclinal deposits of this area is difficult. 
 
 Cincinnati 
 Shoal 
 
 Fig. 4 - Paleogeography at an 
 intermediate stage during 
 Chesterian sedimentation. 
 
 
BRYOZOANS 
 
 TRILOBITE 
 
 CRINOIDS BLASTOIDS 
 
 Phillipsia I x 
 
 Rhomboporo I x 
 
 Archimedes Ix 
 
 BRACHIOPODS 
 
 Plotycrmus \ x 
 
 Pentremites %■/■$ x 
 CORALS 
 
 Brachythyris I x 
 
 Pugnoides l x 
 
 Girtyella I x 
 
 Conmio 2/g x 
 
 Or t ho fetes I x 
 
 Schuchertelto I x 
 
 Echinoconchus I x 
 
ILLINOIS 
 
 GEOLOGICAL 
 
 SURVEY 
 
 7) 
 
 Geologic research and service for the citizens of Illinois since 190S