SURFICIAL GEOLOGY OF WHEELING QUADRANGLE ILLINOIS STATE GEOLOGICAL SURVEY LAKE AND COOK COUNTIES, ILLINOIS STATEMAP Wheeling-SG E. Donald McKay III, Interim Director Michael L. Barnhardt 2008 w c c c e e e w w c QUATERNARY DEPOSITS w w w w Description Unit Interpretation e e c e w w gp w w w HUDSON EPISODE (~12,000 years before present (B.P.) to today) w w w w e dg w e Fill, compacted land, or other Disturbed ground Human-disturbed deposits w e c w disturbed material; highly variable modified during construction of e w in grain size (may range from clay to dg buildings, roads, and landfills; c w w gravel), and may contain construc- w e includes excavations in gravel pits c w dg tion and mining debris. Typical (present over underlying unit) and quarries. w e e c w thickness: variable e e w e w c h-u e c gp c e Silt and clay; occasional sand Cahokia Formation Postglacial (modern) stream w gp lenses; trace gravel; stratified; brown (floodplain deposits) sediments deposited on active w c c e e c to yellowish brown; loose to floodplains; derived mainly from gp c gp compact; may be mottled and eroded loess and diamicton; overlies c w gleyed; some bedding; organic-rich outwash sand and gravel along Des c h-u w e w h-u e c in places. Typical thickness: 1 to 20 Plaines River; may overlie or feet. interfinger with lacustrine silt and k" k"00457 28834 e clay; includes silty slopewash c w c w deposits along footslope and minor c w e drainageways on moraines. w w gp e w c e Peat, muck, marl, and organic-rich Grayslake Peat Organic-rich sediments accumu- e sediment; may contain interbeds of lated in low-lying depressions, k" silt, clay, and very fine to fine sand; gp drainageways, and on floodplains; 35167 e w black to dark brown; sediment may may include small areas of open e w be gleyed and mottled; soft to firm; water; locally intertongued with c w w snail shells common. Typical modern alluvium, or lake sediment; e thickness: 1 to 10 feet. commonly found around lakes and c c e w e marshes and channels connecting e" k"50815 bodies of water. e 28501 c w e w w w c WISCONSIN EPISODE (Late) (~25,000 years - 12,000 B.P.) c k" 47302 w c gp w w e Silt and clay; massive to bedded; Equality Formation Postglacial and glacial proglacial h-u e e dark gray to light gray; calcareous; lake deposits that infill low-lying gp " h-u k"k" k 28917 soft to hard; compact; may be sticky e areas, or depressions in drainage 28496 e e 28859 and plastic; very fine and fine sand channels and where water was e gp e w common along bedding planes; impounded along the fronts of gp e occasional inclusions and lenses of moraines, such as between w e w w w light gray to white silt; some wood moraines of the Lake Border c e fragments; very few clasts; generally Morainic System; at the surface, c h-u abrupt upper and lower contacts. these sediments may interfinger e Typical thickness: 5 to 25 feet. with or be overlain by alluvium; k" 29672 w c k" h-u 28898 e" 48631 e Sand and gravel; stratified; Henry Formation Proglacial fluvial (outwash) 29474 c w c k" e occasionally massive; yellowish to undifferentiated sediments exposed along the Des w w h-u h-u grayish brown; calcareous; loose; Plaines River floodplain and as gp c w gp sand is very fine to very coarse, h-u terraces above present stream level; w w very well to poorly sorted; gravel is deposited as a valley train by gp gp w e c w w very fine to coarse, very well to very meltwater along the glacier termi- c w w e poorly sorted; trace to little amounts nus. w w e e c w of silt and clay, frequently as thin w w beds. Typical thickness: 5 to 120 c 30434k" feet. 47304 k" c c dg c w h-u w h-u Diamicton; silty clay loam to silty Wadsworth Formation Subglacial and ice-marginal gp w 42176 w k" c w w w clay; dark gray to yellowish brown; sediments (till) deposited from w massive; calcareous; compact; firm w Wadsworth glacial ice; sediment that e w w 40228 k" to very hard; pebbly with occasional melted out on top of the glacier or w w w cobbles and boulders; commonly along the ice margin and was w e e e w contains silt and sand inclusions reworked by slope processes and dg and sand and/or gravel lenses; may water; laminated sequences may be c c w gp w e contain pebble-free, silty and clayey more than 40 feet thick, but their c e zones with strongly expressed areal extent is irregular and difficult w w e w laminations that may be interbedded to delineate. with the diamicton; lenses of gp w w c w w saturated silt and very fine sand are gp w loose and runny. Typical thickness: gp c e e w c w 50 to 200 feet. w c w gp gp w c c e Sand and gravel; massive or Henry Formation Proglacial fluvial (outwash) gp e h-u h-u stratified; light yellowish brown to undifferentiated sediments deposited in front of w w grayish brown; calcareous; sand is (cross sections only) advancing Wadsworth glacial ice; c e typically fine-grained with trace fine individual beds are irregular and c w w c gravel; contains some silt beds; h-u discontinuous; more frequent near e w w c gp moderately well sorted; sometimes moraine fronts. water-bearing. e dg w Typical thickness: 3 to 60 feet. c c w Silt and clay; bedded to massive; Equality Formation Glacial proglacial lake deposits c e w c e w dark gray to light brown; calcareous; unnamed tongue that were deposited in front of gp h-u soft to hard; compressable when (cross sections only) Wisconsin Episode glacial ice; dg moist; compact; contains beds of irregular distribution; may interfinger c w very fine to fine sand; some e with sand and gravel or diamicton. w w w dropstones; occasionally deformed; w e common abrupt upper and lower e c contacts. Typical thickness: 5 to 40 w feet. c w w e c c h-u WISCONSIN EPISODE (early) (~25,000 years B.P.) to ILLINOIS EPISODE c c (~200,000 - 130,000 years B.P.) w w c w c Sand, gravel, diamicton, and silt; Older sediment Stratified glacial lake sediments, e w dg pebbly to cobbly sandy loam to silty undifferentiated older diamicton and outwash, and clay loam; light reddish brown to (cross sections only) weathered bedrock widespread but c w c w grayish brown; calcareous; compos- variable thickness and texture w os w ite unit quite variable in texture and makes it difficult to differentiate dg w dg w character; compact; hard to sediment type using drillers' extremely hard; silt is massive to descriptions w crudely stratified with some pebbles; h-u c sand and gravel is mostly composed c h-u w of dolomite clasts with some h-u c w c igneous pebbles and cobbles. w c Typical thickness: 5 to 25 feet. w e c c dg c c PRE-QUATERNARY DEPOSITS w c c dg h-u SILURIAN PERIOD (~443 to 416 million years B.P.) w e w w w dg Rock; predominantly dolomite Bedrock Bedrock associated with shallow w overlain locally by shale; upper marine environment of Silurian w e (cross sections only) c e w surface is commonly fractured with Period; buried by ~120–250 feet of h-u w w h-u crevices and solution cavities; some Quaternary sediments h-u oil staining e e c c c w h-u h-u h-u c e w w w e c c Data Type w w c w e" e Stratigraphic boring e e w c e w e" Water well boring c h-u e k" 26211 Dot indicates boring is to bedrock. gp gp h-u h-u w Contact c c w A A� Line of cross section w h-u e c Note: The county number is a portion of the 12-digit API number c on file at the ISGS Geological Records Unit. Most well and h-u c e w boring records are available online from the ISGS Web site. e w c e Base map compiled by Illinois State Geological Survey from digital data (500dpi DRG) SCALE 1:24,000 Geology based on field work by Michael L. Barnhardt and Jason F. Thomason. provided by the United States Geological Survey. Topography compiled 1988. Planimetry 1 1/ 2 0 1 MILE derived from imagery taken 1998 and other sources. Public Land Survey System and sur- Digital cartography by Jennifer E. Carrell and Jane E.J. Domier, Illinois State Geological 1000 0 1000 2000 3000 4000 5000 6000 7000 FEET vey control current as of 1992. Boundaries current as of 2002. Survey. 1 .5 0 1 KILOMETER North American Datum of 1983 (NAD 83) This research was supported in part by the U.S. Geological Survey National Cooperative Projection: Transverse Mercator Geologic Mapping Program (STATEMAP) under USGS award number 07HQAG0109. The 10,000-foot ticks: Illinois State Plane Coordinate system, east zone (Transverse Mercator) views and conclusions contained in this document are those of the authors and should not 1,000-meter ticks: Universal Transverse Mercator grid system, zone 16 BASE MAP CONTOUR INTERVAL 5 FEET be interpreted as necessarily representing the official policies, either expressed or implied, NATIONAL GEODETIC VERTICAL DATUM OF 1929 of the U.S.