Surficial Geology of Grantfork Quadrangle, Madison County, Illinois

              Illinois Geologic Quadrangle Map
IGQ Grantfork-SG
Base map compiled by Illinois State Geological Survey from digital data provided by the United States Geological Survey. Topography by photogrammetric methods from aerial photographs taken 1973. Field checked 1974.
North American Datum of 1927 (NAD 27)
Projection: Transverse Mercator
10,000-foot ticks: Illinois State Plane Coordinate system, west zone (Transverse Mercator)
1,000-meter ticks: Universal Transverse Mercator grid system, zone 16
Recommended citation:
Grimley, D.A., and A.C. Phillips, 2006, Surficial Geology of Grantfork Quadrangle, Madison County, Illinois: Illinois State Geological Survey, Illinois Geologic Quadrangle Map, IGQ Grantfork-SG, 1:24,000.
Geology based on field work and data compilation by D. Grimley and A. Phillips, 2004–2005.
Digital cartography by J. Carrell and J. Domier, Illinois State Geological Survey.
The Illinois State Geological Survey, the Illinois Department of Natural Resources, and the State of Illinois make no guarantee, expressed or implied, regarding the correctness of the interpretations presented in this document and accept no liability for the consequences of decisions made by others on the basis of the information presented here. The geologic interpretations are based on data that may vary with respect to accuracy of geographic loca­tion, the type and quantity of data available at each location, and the scientific and technical qualifications of the data sources. Maps or cross sections in this document are not meant to be enlarged.
IGQ Grantfork-SG Sheet 1 of 2
SURFICIAL GEOLOGY OF GRANTFORK QUADRANGLE
MADISON COUNTY, ILLINOIS
David A. Grimley and Andrew C. Phillips
20061°APPROXIMATE MEANDECLINATION, 2006MAGNETIC NORTHTRUE NORTHROAD CLASSIFICATIONPrimary highway,hard surfaceSecondary highway,hard surfaceLight-duty road, hard orimproved surfaceUnimproved roadInterstate RouteU.S. RouteState Route
ADJOINING
QUADRANGLES
1 Worden
2 New Douglas
3 Sorento South
4 Marine
5 Pocahontas
6 St. Jacob
7 Highland
8 St. Rose
BASE MAP CONTOUR INTERVAL 10 FEET
SUPPLEMENTARY CONTOUR INTERVAL 5 FEET
NATIONAL GEODETIC VERTICAL DATUM OF 1929
For more information contact:Illinois State Geological Survey 615 East Peabody Drive
Champaign, Illinois 61820-6964
(217) 244-2414
http://www.isgs.uiuc.edu12345678
Released by the authority of the State of Illinois: 2006
7
000 FEET10001000020003000400050006000.51 KILOMETER10SCALE 1:24,0001/2101 MILE
Illinois Department of Natural Resources
ILLINOIS STATE GEOLOGICAL SURVEY
William W. Shilts, Chief
dg
cprpl(o)g&b-lb-opl-hb-cInterpretationMan-made fill or excavations; includes large areas of disturbed sediment and borrow areas such as near interstate highways or damsAlluvium (river deposits) in stream valley floodplains; derived from reworking and sorting of loess, diamicton, and sand and gravel exposed in uplands and slopes; includes some historical depositionLoess (windblown silt); includes redeposited loess in sloping areas; the Peoria and Roxana Silts are generally not easily differentiated due to similar physical properties, alteration, and thinness of unitsIce-contact sediment; upper portion may contain Sangamon Geosol; includes debris flows, inclusions of older material, fractures or faults, and possible buried remnants of eskers or kames; intertongues with the Glasford Formation; contact lines are not shown on map where unit is buriedOutwash (proglacial sediment); occurs near surface along Sugar Creek in the southeast and Corlock Branch in the southwest; occurs underneath the Cahokia Formation in Sand Creek, Sugar Fork, and East Fork Silver Creek valleysTill and ice-marginal sediment; upper few feet of diamicton typically contains Sangamon Geosol solum; upper portion may include sand and gravel lenses and supraglacial deposits; lower portion is mainly basal till; crops out along steep slopesAccretionary sediment in former shallow depressions including shallow lake, stream, and slope deposits (colluvium); the Yarmouth Geosol is developed throughout the unit but may be truncatedTill and ice-marginal sediment; generally contains evidence of Yarmouth Geosol weathering or oxidation in upper 10 feet; the alteration zone may or may not be truncatedAlluvium and colluvium; nonglacial; immediately underlain by bedrock, shale; may contain one or more paleosols, particularly in upper few feetInterpretationBedrock or near-surface bedrock (within 5 feet of land surface); mapped in the northeastern and southwestern portions of quadrangle and in many areas along Highland Silver Lake QUATERNARY DEPOSITSUnitHUDSON EPISODE (~12,000 years before present (B.P.) to today)Disturbed groundCahokia FormationWISCONSIN EPISODE (~75,000–12,000 years B.P.)Peoria and Roxana Silts(where > 5 feet thick)ILLINOIS EPISODE (~200,000–130,000 years B.P.)Hagarstown Member, Pearl Formation(< 5 feet of loess cover)(stipples where buried)Pearl Formation(outwash facies)(< 5 feet of loess cover)Glasford Formation(< 5 feet of loess cover)PRE-ILLINOIS EPISODE (~700,000–450,000 years B.P.)Lierle Clay Member,Banner Formation(cross sections only)Omphghent member,Banner Formation(cross sections only)Canteen member,Banner Formation(cross sections only)PRE-QUATERNARY DEPOSITSUnitPennsylvanianbedrockDescriptionFill or removed earth; sediment of various types; up to 30 feet thickSilty clay loam, silty clay, silt loam, and loam; occasional sand and gravel beds; dark brown to gray; massive to well stratified; noncalcareous; up to 25 feet thickSilt to silt loam; yellowish brown to gray to brown; massive to blocky structure; friable; noncalcareous; contains modern soil solum in upper 3 to 5 feet; up to 12 feet thickIntermixed loam, sand and gravel, diamicton, and silty clay; high variability with zones of well-sorted sand and gravel in some areas; strong brown to yellowish brown to light olive-gray; upper 10 to 15 feet commonly more fine grained and weathered; soft to moderately stiff; fractured and faulted in places; noncalcareous to calcareous; up to 65 feet thickSand with some gravel; may include silty or clayey beds; gray to yellowish brown; stratified; moderately to well sorted; up to 15 feet thickPebbly loam diamicton; may contain sand and gravel lenses; light olive-brown to dark gray; main portion is generally massive, very stiff to hard, calcareous, and contains 5–10% pebbles (typically < 2-inch diameter); upper few feet weathered to brown or yellowish brown and softer with more clay (silty clay loam); up to 60 feet thick Silty clay to silty clay loam; few pebbles; crudely to well stratified; moderately stiff; greenish gray to olive-gray to dark gray to yellowish brown; noncalcareous; up to 15 feet thickPebbly silty clay loam to loam diamicton; may contain thin sand and gravel lenses (up to 5 feet thick); light olive-brown to dark olive-gray to dark gray; massive to weakly laminated; moderately stiff to stiff; noncalcareous to calcareous; up to 45 feet thickSilty clay loam to pebbly clay loam diamicton; olive-gray to greenish gray to brown; massive, bedded, or laminated; contains subrounded, commonly platy chert pebbles; noncalcareous; oxidized in upper few feetDescriptionShale, sandstone, and limestone; ranges from greenish gray to light gray to yellow-brown to black; laminated to bedded to massive; noncalcareous to calcareous; limestone beds ~3 feet thick (Carthage Limestone member, Bond Formation) underlain by black shale are common along northern Highland Silver Lake regionAA􀀁􀄤$T"e"e"e$T"e"kSG26211OutcropOutcrop in field notes (ISGS archives)Stratigraphic boringWater well boringEngineering boringOther boring, including oil and gasLabels indicate samples (S) or geophysical log (G). Boring and outcrop labels indicate the county number.Dot indicates boring or outcrop is to bedrock.ContactInferred contactLine of cross sectionData TypeNote: The county number is a portion of the 12-digit API number on file at the ISGS Geological Records Unit. Most well and boring records are available online at the ISGS Web site.ABA􀀁􀅂B􀀁􀄣#"kS"kS"k"k"k"e"e"e"e"e"e"k"e"k"k"k"k"k"e"k"e"e"k"k"k"e"e"e"kS"kS"k"k"k"kS"k"k"e"kS"kS"e"e"e"kG"kG"kG"kG"kG"kG"kG"kG"kG"kG"kG"kG#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0"eSG"eSG"kS"e"k"kS"kS#0#0#0#0"SGT#0"eSG"e"k"k"k"k"k"kS"k"k"e"k"kS"kS"e"kS"kS"kS"e"kS"k#0"e"kS"kS"SG#0"e"e"e"e"e"kS"e"ekk"kkk#T#T#T#T#T#T#T#T#T#T#T#T#T#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&gggggggggdgdgprprcg&ggdgggcgpl-h&gggggggggpl-h&gggggggggdgcc&ggcgcgggggpl-hgggcgggg&pl(o)&pl-hgpl(o)gg&prgggggcpl(o)cdgprpl(o)g&g&cg&pl-hg&&&dgpl-hgccccprprprccccprprcprprprprprpl-h