IGQ Columbia-SG Sheet 2 of 2
hgbedrockc(s)ggprprc(c)prgc(s)prprprpbggprccpbcccc(c)c(f)c(s)dgremoved earthdgb-ltrbedrock004292165930660 (quarry exposure)22283227682224622295263162243430671 (roadcut)2761825910275512635503297017252489430662, 30663 (outcrops)Monroe CountySt. Clair CountyI-255US Route 50State Route 3300400500600300400500600700700Elevation(feet)AAWestEast200200004530272023198 (outcrop)23180 (outcrop)2234222317223182487923200 (outcrop)0045723177 (outcrop)2166700454223192275123218 (outcrop)2144422352227532275222754geprhc(s)gcprc(f)ecprpbcprccggccprprggprprc(c)dgbedrockbedrock60070080090060070080090010001000Elevation(feet)BBWestEastSt. Clair CountyMonroe CountyState Route 300103004592211900441002080060322564002122173200523209312274823196 (excavation)2276720712206492270622750ggprprprhc(f)c(s)prprpbprcc(c)cbedrockbedrocktrtrtrtr300400500600300400500600700700Elevation(feet)CCWestEastMississippi River ValleyState Route 3
Introduction
The Columbia Quadrangle, located in southwestern Illinois about 15 miles south of St. Louis, contains predominantly glaciated and loess-covered uplands, as well as an area of the Mississippi River valley in the western quarter of the map. Near-surface deposits on the uplands are dominated by thick loess (15 to 50 feet on uneroded uplands) deposited during the last glaciation (Wisconsin Episode) and underlain by glacial till of the penultimate glaciation (Illinois Episode). In the Mississippi River valley, up to about 110 feet of waterlain clay, silt, sand, and gravel (Wisconsin Episode and postglacial) is found above bedrock.
Methods
This surficial geologic map is based in part upon soil series parent materials compiled from the St. Clair County (Wallace 1978) and Monroe County (Higgins 1984) soil surveys, but was considerably modified based upon field observations, Illinois State Geological Survey (ISGS) field notes, and subsurface data obtained from well log data, coal test boring data, Illinois Department of Transportation boring records, boring logs from local consulting companies (particularly Shively Geotechnical, Inc. and Philip Services Corporation), E.D. McKay’s thesis (1977), and drilling operations performed as part of this STATEMAP project. Areas of near-surface till and postglacial alluvium are based in part on soil parent material data of Wallace (1978) and Higgins (1984). Subsurface boring data on file at the ISGS and new outcrop studies were utilized for drafting of the three cross sections.
Quaternary Geology
Uplands
The underlying bedrock in the Columbia Quadrangle is predominantly Mississippian limestone with some Pennsylvanian shale, limestone, sandstone, and coal in the Columbia syncline (Devera 2000). Bedrock outcrops occur along much of the Mississippi River valley bluffs and also along many high-gradient streams that have eroded through surficial deposits. Some of the Herrin Coal in this area has been mined from outcrops and in the subsurface during the past century (Damberger et al. 1997). Bedrock residuum is occasionally preserved in the subsurface at the interface between bedrock and Quaternary sediments. Pre-Illinois Episode till was not found in outcrop or reliably in core samples. Some thin deposits of pre-Illinois alluvium, loess, colluvium, and/or lacustrine deposits appear to be present in a few cores, but the age of these sediments is not entirely clear due to erosional truncation of the Yarmouth Geosol, an interglacial paleosol that separates pre-Illinois Episode from Illinois Episode sediments. In one core (no. 22768; Sec. 4, T1S, R10W), 6 feet or more of noncalcareous, silt loam to silty clay with rare pebbles (probable Yarmouth or pre-Illinois Episode accretionary deposits) is present below calcareous Illinois Episode deposits. This unit, classified as the Lierle Clay Member of the Banner Formation (b-l, Willman and Frye 1970), is shown only in cross section A–A9, but is likely found locally in other areas as well. The Lierle may have originated from resedimented loess and thin till deposits in surrounding uplands.
Illinois Episode deposits commonly include till, lacustrine sediment, waterlain sand, and loess. Such deposits have remained largely intact in relatively flat landscapes because the Illinois Episode was the last (and perhaps only) glaciation in this area. However, in the high-relief western areas, these units were more apt to have been eroded and were likely initially thinner due to thin glacial ice or a limited duration of glaciation near the Illinoian ice margin. The Glasford Formation till, typically a pebbly silt loam to silty clay loam diamicton, is as much as 65 feet thick in the eastern areas of the map. However, the Glasford thins to 5 to 10 feet thick in some western areas. Striations (N 77º W) in a sandstone at site 23198, southwest of the town of Columbia, indicate ice directional advance from slightly south of east. Spruce or larch wood fragments were found in lacustrine silt below unoxidized till and above the Lierle Clay Member in a stratigraphic test core (no. 22768). This core was drilled into a preglacial lowland or ancestral bedrock valley (Panno et al. 2008a) near Hill Creek. This silt (Petersburg Silt) was also found immediately underlying the Glasford Formation in many outcrops and boreholes in bedrock valleys and lowlands several miles northeast of this quadrangle (Grimley and McKay 2004). The Petersburg Silt and Glasford Formation are not separated by a buried interglacial-quality soil (no evidence of B horizon or leaching zone). Thus, ice advance into shallow proglacial or slackwater lakes is interpreted to have immediately followed deposition of the lake deposits, which occur up to ~450 to 475 feet elevation in ancestral bedrock valleys or lowlands. Silty lake deposits or loess above the Glasford Formation, classified as the Teneriffe Silt, are also present in many areas, but such deposits are relatively thin (<10 feet). The Teneriffe Silt, principally a weathered loess but containing waterlain beds in places, was found to be 5 to 10 feet thick in a few stratigraphic test holes and is thus shown as a blanketing layer above the Glasford Formation in cross sections A–A9 and C–C9. The Sangamon Geosol, which is ubiquitous over uneroded upland areas of the quadrangle, was developed into the Glasford Formation and/or Teneriffe Silt subsequent to deposition of these units. Soil development, resulting in increased soil structure and clay content, continued until loess deposition was initiated during the following ice age.
Loess deposits (windblown silt, Wisconsin Episode) are up to 50 feet thick on upland crests along the Mississippi River valley bluffs but thin dramatically to the southeast to less than 15 feet on uplands. The source of the loess was eolian deflation from outwash sediment in the broad American Bottoms in the Mississippi River valley in the western part of this quadrangle and further west. Loess deposits consist of Peoria and Roxana Silts; the Peoria Silt is between ~30 to 100% thicker than the Roxana Silt (McKay 1977). Both units are predominantly silt, typically with less than 5% sand and less than 20% clay when relatively unweathered. Roxana Silt was deposited between about 55,000 and 28,000 radiocarbon (14C) years before present, whereas Peoria Silt was deposited between about 25,000 and 12,000 14C years before present (McKay 1977, Grimley et al. 1998). In areas of numerous sinkholes in the north-central and southwestern portion of the map (Panno et al. 2008b), loess deposits drape thin till and limestone bedrock; loess in the sinkhole fills has been remobilized and resedimented by colluvial and fluvial processes.
Mississippi River Valley
Deposits in the Mississippi River valley (locally known as the American Bottoms) consist of several sequences of waterlain deposits with a general fining-upward sequence. The oldest and coarsest Mississippi River deposit is a basal sand and gravel (Henry Formation, Hansel and Johnson 1996), which is as much as 50 feet thick and deposited during the last glaciation (Wisconsin Episode). Fluvial sediment associated with Illinois and pre-Illinois Episode glaciations were presumably eroded prior to or concurrent with Henry Formation deposition, although unmappable remnants may remain. Above the Henry Formation is a well-sorted medium to fine sand unit with little gravel. This middle layer is interpreted to be Cahokia Formation (postglacial river deposits), based on textural changes and previous studies of the valley sediments (Bergstrom and Walker 1956, Willman and Frye 1970). The upper third of deposits in the valley (cross section A–A9) consists of a mixture of sandy point bar deposits and silty clay swale fills (backswamp and abandoned channel deposits of the Mississippi River). Channel abandonment occurred between about 6,000 and 2,500 14C years before present based on the regional stratigraphy and radiocarbon dates on material in the younger Goose Lake meander (White et al. 1984, Booth and Koldehoff 1999). Young alluvial fan deposits, containing silty redeposited loess, reach out onto the valley adjacent to the major creeks emanating from the bluffs (Carr Creek, Little Carr Creek, and Palmer Creek). The fan deposits appear to overlie backswamp deposits and thus are presumably less than 2,500 14C years old, based on ages determined for abandoned channels in the American Bottoms (White et al. 1984, Booth and Koldehoff 1999). As much as 6 feet of silt in fan deposits near Edgemont originated during historical times as a result of upland erosion by deforestation, farming, and construction of suburban subdivisions (Booth and Koldehoff 1999). In most of the stream valleys east of the Mississippi River valley, a mainly silty and sandy fluvial sediment (Cahokia Formation) is found to be generally 5 to 30 feet thick. The Cahokia Formation in small tributary valleys has a large component of redeposited Peoria and Roxana Silts. Erosion of these loess units from uplands and redeposition in lowlands has been accelerated due to human activity in historical times.
Material Resources
Sand and Gravel
As much as 120 feet of sand and gravel (but mostly sand) occurs in the Mississippi River valley (cross section A–A9). Dredging for sand and gravel is currently in operation in the American Bottoms several miles northeast of this quadrangle (Grimley and McKay 2004). Sand is obtained from about 60 to 90 feet depth (below clayey or fine sand alluvium) and is used for fill and construction uses. However, the gravel content is low, somewhat limiting the use of this sediment by the construction industry. As indicated by data from water wells located in the floodplain (see cross sections), more desirable coarse river sand (Henry Formation) is commonly buried by 50 feet of clay, silt, dirty sand, or fine to medium sand (Cahokia Formation).
Groundwater
Henry Formation sand and gravel and Cahokia Formation sand in the Mississippi River floodplain constitute the most significant Quaternary aquifer of this quadrangle (cross sections and Bergstrom and Walker 1956). Yields from this aquifer are high; however, the potential for contamination is generally high because of the relatively thin and discontinuous covering of silt and clay (0–50 feet). The potential for contamination also depends on hydraulic gradients and overall position in the three-dimensional groundwater flow system. In upland areas, groundwater supplies are primarily from bedrock aquifers (Panno et al. 1997). Sand and gravel lenses within the local till are not sufficiently thick or extensive for more than a low-yield water supply and, in some cases, may be unsaturated due to high relief and lower water levels.
Environmental Hazards
Karst (Sinkhole and Cavern Development)
Karst topography is evident at the surface in many areas of the quadrangle where limestone bedrock is within ~25 feet of land surface. In such areas, where thin loess and residuum overlie pure limestone, such as the Salem or St. Louis Formations (Devera 2000), sinkhole and underground cavern development is most prevalent (Panno et al. 1997, Panno et al. 2008b). Underground drainage in karstic areas, such as near Alton, Illinois, can be rapid (>0.5 mile/day) and commonly follows joint sets toward the Mississippi River valley (Lamar 1928). Bedrock aquifers underlying karstic regions are thus highly susceptible to contamination because groundwater recharge flows quickly into cavernous bedrock and is not filtered through soil, clay, or slowly permeable bedrock (Panno et al. 1997, Panno and Weibel 1998). Karstic regions also pose a hazard to building structures because of the danger of sinkhole collapse and widening.
Mass Wasting
Erosion, undercutting, and slumping of thick loess deposits at bluff edges are a potential hazard (Killey et al. 1985). Slumping commonly occurs in this area when water collects at the base of relatively permeable loess on top of the clayey Sangamon Geosol/Glasford Formation, at the Peoria/Roxana Silt contact, or at other permeability contrasts. Higher-pore water pressures in such perched water tables increase the likelihood of slumping or failure along steep slopes. Natural slumps in glacial materials have been noted along several creek cutbanks, such as at outcrop sites 23182 (upper Carr Creek Valley), 23189 (Hill Lake Creek valley), 23190 (Palmer Creek valley), and 23201 (Prairie du Long Creek valley).
Soil Erosion
Steep slopes along ravines and bluffs are subject to severe soil erosion due to the nature of loessal soils. Areas mapped as Peoria and Roxana Silt have loose, windblown, near-surface silt deposits that are soft and weakly cohesive and thus have a low shear resistance. These loess deposits are easily eroded by running water during heavy rainfalls. Runoff during rainstorms can quickly erode into and enlarge rills and gullies, thereby accelerating the process of erosion, as water is channeled into the growing drainage system. Mass wasting processes (slumping) and agricultural practices also greatly contribute to the amount of sediment eroded into creek watersheds.
Acknowledgments
Discussions with Michael Barnhardt, Steven Brown, Joseph Devera, and Andrew Phillips aided considerably with this mapping project and report. Madalene Cartwright aided with drilling and sample descriptions. Dale Meyer (Meyer Drilling) obtained for us high-quality continuous cores from several locations. Janet Jacoby (Shively Geotechnical, Inc.) and William Graham (Philip Services Corp.) were instrumental in providing several high-quality engineering boring data. This research was supported in part by the U.S. Geological Survey (USGS) National Cooperative Geologic Mapping Program (STATEMAP) under USGS award number 99HQAG0166.
References
Bergstrom, R.E., and T.R. Walker, 1956, Groundwater geology of the East St. Louis Areas, Illinois: Illinois State Geological Survey, Report of Investigation 191, 44 p.
Booth, D.L., and B. Koldehoff, 1999, The emergency watershed project: Archeological investigations for the 1998 Metro East ditch cleanout project in Madison and St. Clair Counties, Illinois, T.E. Emerson, ed.: Urbana-Champaign, Illinois, Illinois Transportation Archeological Research Program, Research Reports no. 62, 417 p.
Damberger, H.H, B.J. Stiff, and J.K. Hines, 1997, Coal industry in Illinois: Illinois State Geological Survey, Illinois Map 9, 1:500,000.
Devera, J., 2000, Bedrock geology of Columbia Quadrangle, Monroe and St. Clair Counties, Illinois: Illinois State Geological Survey, USGS STATEMAP contract report, Illinois State Geological Survey, http://www.isgs.uiuc.edu/maps-data-pub/maps.shtml.
Grimley, D.A., L.R. Follmer, and E.D. McKay, 1998, Magnetic susceptibility and mineral zonations controlled by provenance in loess along the Illinois and central Mississippi valleys: Quaternary Research, v. 49, p. 24–36.
Grimley, D.A., and E.D. McKay, 2004, Surficial geology of French Village Quadrangle, St. Clair County, Illinois: Illinois State Geological Survey, Illinois Geologic Quadrangle Map, IGQ French Village-SG, 1:24,000.
Hansel, A.K., and W.H. Johnson, 1996, Wedron and Mason Groups: Lithostratigraphic reclassification of deposits of the Wisconsin Episode, Lake Michigan Lobe: Illinois State Geological Survey, Bulletin 104, 116 p.
Higgins, S.K., 1984, Soil survey of Monroe County: University of Illinois Agricultural Experiment Station and United States Department of Agriculture, 174 p.
Killey, M.M., J.K. Hines, and P.B. DuMontelle, 1985, Landslide inventory of Illinois: Illinois State Geological Survey, Circular 534, 27 p.
Lamar, J.E., 1928, Karst topography and sanitary engineering at Alton, Illinois: Transactions of the Illinois Academy of Science, v. 20, p. 261–264.
McKay, E.D., 1977, Stratigraphy and zonation of Wisconsinan loesses in southwestern Illinois: University of Illinois at Urbana-Champaign, Ph.D. thesis, 242 p.
Panno, S.V., J.C. Angel, D.A. Grimley, C.P. Weibel, and B.J. Stiff, 2008a, Bedrock topography of Columbia Quadrangle, Monroe and St. Clair Counties, Illinois: Illinois State Geological Survey, Illinois Geologic Quadrangle Map, IGQ Columbia-BT, 1:24,000.
Panno, S.V., J.C. Angel, D.O. Nelson, C.P. Weibel, and D.E. Luman, 2008b, Sinkhole distribution and density of Columbia Quadrangle, Monroe and St. Clair Counties, Illinois: Illinois State Geological Survey, Illinois Geologic Quadrangle Map, IGQ Columbia-SD, 1:24,000, report, 6 p.
Panno, S.V., I.G. Krapac, C.P. Weibel, and J.D. Bade, 1997, Groundwater contamination in karst terrain of southwestern Illinois: Illinois State Geological Survey, Environmental Geology 151, 43 p.
Panno, S.V., and C.P. Weibel, 1998, Karst landscapes of Illinois: Dissolving bedrock and collapsing soil: Illinois State Geological Survey, Geobit 6, 4 p.
Wallace, D.L., 1978, Soil survey of St. Clair County, Illinois: University of Illinois Agricultural Experiment Station and United States Department of Agriculture, 114 p.
White, W.P, S. Johannessen, P.G. Cross, and L.S. Kelly, 1984, Environmental setting, in C.J. Bareis and J.W. Porter, eds., American Bottom archeology: A summary of the FAI-270 project contribution to the culture history of the Mississippi Valley: Urbana, Illinois, University of Illinois Press, p. 13–33.
Willman, H.B., and J.C. Frye, 1970, Pleistocene stratigraphy of Illinois, Illinois State Geological Survey, Bulletin 94, 204 p.
Cross SectionsDiamicton, massive silt, or other fine-grained sedimentLaminated silt and clayMainly fine to very fine sand with some silt and clay and medium sandMainly medium sand with some fine and coarse sandMedium to coarse sand with gravelContactInferred contactBoring within 1,000 feet of line of cross sectionBoring projected more than 1,000 feet to line of cross sectionHorizontal scale: 1 inch = 2,000 feetVertical scale: 1 inch = 100 feetVertical exaggeration: 20×Cahokia FormationDisturbed groundCahokia Formation (silty fan deposits)Cahokia Formation(clayey facies)Cahokia Formation (sandy facies)Equality FormationHenry Formation Peoria and Roxana Siltsdgcprehc(f)c(c)c(s)gpbb-ltrTeneriffe SiltGlasford FormationPetersburg SiltLierle Clay Member, Banner FormationNear-surface bedrock
