Surficial Geology of Ames Quadrangle, Monroe and Randolph Counties, Illinois

              Illinois Geologic Quadrangle Map
IGQ Ames-SG
Base map compiled by the Illinois State Geological Survey from digital data (Raster Fea­ture Separates) provided by the United States Geological Survey. Topography compiled from imagery dated 1968. Field checked 1970.
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 15
Recommended citation:
Grimley, D.A. and G.A. Shofner, 2008, Surficial Geology of Ames Quadrangle, Monroe and Randolph Counties, Illinois: Illinois State Geological Survey, Illinois Geologic Quad­rangle Map, IGQ Ames-SG, 2 sheets, 1:24,000.
Geology based on field work and data compilation by David A. Grimley 2006–2007 and Greg A. Shofner, 2002–2004.
Digital cartography by Jennifer E. Carrell, Zahra Golshani, and Jane E.J. Domier, Illinois State Geological Survey.
This map was funded in part by the U.S. Geological Survey, National Cooperative Geologic Mapping Program under USGS award number 06HQAG0053. The views and conclusions contained in this document are those of the authors and should not be interpreted as neces­sarily representing the official policies, either expressed or implied, of the U.S. Government.
The Illinois State Geological Survey and the University 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 Ames-SG Sheet 1 of 2
SURFICIAL GEOLOGY OF AMES QUADRANGLE
MONROE AND RANDOLPH COUNTIES, ILLINOIS
David A. Grimley and Greg A. Shofner
2008MAGNETIC NORTHAPPROXIMATE MEANDECLINATION, 2008TRUE NORTH / °12ROAD CLASSIFICATIONPrimary highway,hard surfaceSecondary highway,hard surfaceLight-duty road, hard orimproved surfaceUnimproved roadState Route
ADJOINING
QUADRANGLES
1 Waterloo
2 Paderborn
3 New Athens West
4 Renault
5 Red Bud
6 Bloomsdale
7 Prairie du Rocher
8 Evansville
BASE MAP CONTOUR INTERVAL 20 FEET
NATIONAL GEODETIC VERTICAL DATUM OF 1929
12
345678
© 2008 by The Board of Trustees of the University of Illinois. All rights reserved.
7000
FEET10001000020003000400050006000.51 KILOMETER10SCALE 1:24,0001/2101 MILE
Institute of Natural Resource Sustainability
William W. Shilts, Executive Director
ILLINOIS STATE GEOLOGICAL SURVEY
E. Donald McKay III, Interim Director
For more information contact:
Institute of Natural Resource Sustainability
Illinois State Geological Survey
615 East Peabody Drive
Champaign, Illinois 61820-6964
(217) 244-2414
http://www.isgs.illinois.edu
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ceprgbM(ls)M(ss)M(sh)pyQUATERNARY DEPOSITSUnitHUDSON EPISODE (~12,000 years before present (B.P.) to today)Disturbed groundCahokia FormationPeyton FormationWISCONSIN EPISODE (~55,000–12,000 years B.P.)Equality Formation Areas where buriedPeoria and Roxana Silts(>5 feet thick)ILLINOIS EPISODE (~200,000–130,000 years B.P.)Glasford FormationPRE-ILLINOIS EPISODE (~700,000–400,000 years B.P.)Banner Formationundifferentiated(cross sections only)MISSISSIPPIAN BEDROCKUnitMississippianlimestoneMississippiansandstoneMississippianshale DescriptionFill or removed earth; sediment of various types; up to 15 feet thickSilt loam to loam to sandy loam to gravelly sand; sand and gravel beds are more common in lower portions of unit or as a basal lag (<2 feet thick); dark brown to dark yellowish brown to brownish gray; massive to well-stratified; medium to stiff consistency; noncalcareous; up to 20 feet thickSilt loam to pebbly silt loam to pebbly silty clay loam diamicton; brown to yellow brown; massive to crudely stratified; pebbles and cobbles are generally angular and typical of local sedimentary bedrock; noncalcareous; up to 10 feet thickSilty clay loam to silty clay; brown to grayish brown to dark gray; massive to faintly laminated; soft to medium consistency; leached to calcare-ous; up to 15 feet thickSilt loam to silty clay loam; brown to yellowish brown to grayish brown (upper part) to slightly pinkish brown (lower part); massive to blocky struc-ture; friable; medium to stiff consistency; mainly leached of carbonates; more clayey and more soil structure in upper few feet (modern soil); up to 15 feet thickPebbly silty clay loam, silty clay, or clay loam diamicton (within 5 feet of surface); contains few sand and gravel bodies; yellowish brown to light olive-brown to dark gray (at depth); diamicton is generally massive; stiff to very stiff; commonly fractured or jointed; leached (upper portion) to calcareous (lower portion); contains sandstone, shale, carbonate, and coal pebbles (typically <2 inches); few igneous/metamorphic erratics; upper few feet may be weath-ered to reddish brown or mottled with blocky structure; up to 60 feet thickPebbly clay to clay loam diamicton; includes some sand and gravel bodies; yellowish brown to grayish brown; mas-sive to weakly laminated; stiff to very stiff; noncalcareous to calcareous (at depth); up to 15 feet thick DescriptionLimestone bedrock (outcrops or within 5 feet of surface); yellowish brown to brownish gray; stratified; hard; commonly contains marine fossils such as crinoids, bryozoans, brachio-pods, blastoids, and gastropods; calcareous; includes areas or interbeds of sandstone, chert, and/or shaleSandstone bedrock (outcrops or within 5 feet of surface); orange-brown to pale olive to light gray; generally fine grained; laminated to bedded to cross-bedded; hard where unweath-ered (otherwise somewhat friable); may contain herring-bone structure; mainly noncal-careous with zones having calcite cement; includes few areas of limestone and/or shaleShale bedrock (outcrops or within 5 feet of surface); reddish brown to gray; laminated to bedded; very stiff to hard; may be fractured; mainly noncalcareous with some calcareous zones; includes areas or interbeds of limestone, chert, and/or sand-stoneInterpretationMan-made fill or excavations; includes small areas of disturbed sediment in the northeast quarter of the map near the town of Red BudAlluvium (river deposits); in stream valley floodplains; derived from fluvial reworking and sorting of loess, diamicton, sand, and bedrock exposed in uplands and slopes; coarser alluvium is more common in higher-gradient western water-sheds such as Dry Fork and South ForkColluvium (deposited by gravity along slopes); derived from creep, slumping, or land-slides of local materials (loess, diamicton, sand, and/or bedrock) exposed in sloping areas; also common in areas with sinkholes (karst)Lake deposits; likely deposited as slackwater sediment in Horse Creek during peak glacial aggradation of the Mississippi River; terraces occur up to about 420 feet above sea level; includes up to a 4-foot cover of loess; also occurs below Cahokia Formation alluviumLoess (windblown silt); includes areas of redeposited loess along sloping areas and in sinkholes; mapped where >5 feet thick; approximately upper two-thirds of unit is Peoria Silt (where uneroded) and lower one-third is Roxana Silt (slightly pinkish brown); generally thickest in uneroded areas to the southwestTill and ice-marginal sedi-ment; upper few feet of diamic-ton may contain Sangamon Geosol alteration; although mainly till, this unit includes minor occurrences (generally <10 feet thick) of proglacial outwash, supraglacial deposits, and lake deposits; crops out along steep slopes in much of the quadrangle; locally covered by <5 feet of loessTill and ice-marginal sedi-ment; upper 10 feet or so may contain weathering or oxidation attributed to the Yarmouth Geosol; this alteration zone may be partially eroded or truncated by younger units; distribution in subsurface is patchy and may include zones of proglacial outwash or residuum; overlain by Glasford FormationInterpretationShallow marine environment; includes St. Louis and St. Genevieve Limestones in western areas (with karst), Renault Limestone in central and southern areas, and undifferentiated Chesterian limestones in northeastern areasDeltaic or fluvial environment; includes some tidal sequences; predominantly Aux Vases Sandstone in western areas with minor areas of Cypress Sandstone in eastern areasMarine or deltaic environ-ment; includes areas of Paint Creek Formation and Yankee-town Formation; outcrops mainly in south-central areasAA􀀁􀄤$T"e"e"e"e"kSG26211OutcropStratigraphic boringWater well boringEngineering boringOther boring, including oil and gasLabels indicate samples (S) or geophysical log (G). Boring and outcrop labels indicate the county number.Dot indicates boring is to bedrock.Unit Contact TypeHorizontal accuracy generally within 200 feet Horizontal accuracy may exceed 200 feetApproximate border of Illinois Episode till. Glasford Formation till has not been found south or west of this line.Approximate border of pre-Illinois Episode till. Banner Formation till has not been found south or west of this line. This line is based on limited data, and the Banner till is patchy in distribution northeast of this line. Line of cross sectionData TypeNote: The county number is a portion of the 12-digit API number on file at the ISGS Geological Records Unit. Most well and boring records are available online from the ISGS Web site."e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e"e$e$T$T$T$T$T"e"e"e"e$T$TRed BudIllinois Episode till borderm"ek"k"k"k"k"k"k"k"k"k"k"k"k"k"k"k"k"k"kS"eS"kS"eS"k"k$T"k"k"k"k"k"k"k"k"e"k"k"e"k"k"k"k#0#0#0#0#0#0#0#0#0#0#0#0#0#0#0$T$T#0$T$T$T$T$T$T$T$T$T$T$T$T#0#0$T#0$T#0$T$T#0$T$T$T#0#0#0$T$T#0"kS$0$T"kSG"kSG"kS#0"kS$T$T$T$T$T$T$T$T$T$T$T$T$T$T$TprprprprprprprprprprprprcprprprccgcgcgggprccggccgM(ss)cggggggcgggggggcggggpyM(ss)M(ss)cgpygM(ss)gggM(ss)cggpygggcpygeggggcgggcgggM(ls)gM(ss)ggprgggggggcgpycM(ss)M(ss)M(ss)gcgcgegggprggggcggcgM(ls)gpycgggpygggM(ls)epycgegggcggM(ss)M(ls)pygpyecgprgggcM(ss)M(ss)pyegcggcgggM(ls)M(ls)gcpycdgccpygcpregM(ls)gggcggpypygM(ls)ggpycgprcceggM(ls)gpyepygggcprgdgggM(ls)gM(ss)M(ss)M(ss)M(ls)ceM(ls)pyggM(ls)dgpyggggM(ls)M(ls)pygdgpyM(ls)M(ls)M(ls)pyM(ls)M(ls)prgM(ls)cM(ls)pygM(ls)M(ls)gpypygM(ls)M(ss)M(ls)cM(ss)pyprpyM(sh)M(ls)M(ls)M(sh)gM(ls)pyM(ss)ggpyprM(sh)M(ls)M(ss)cM(ls)M(ls)M(ls)cM(sh)M(sh)M(sh)M(ls)M(ls)gM(ls)M(ss)M(ss)M(ss)M(ss)M(ls)M(ls)prcggcgcccggAA􀀁􀅂BB􀀁􀄲230662306523062230612306026525265232652226521265242652026518230592305823054230572651723055230532305223051230502304923056230482347265152651426513230462304523043230412303923038230372303623035230342303323032230312308123091230902308823078230762307523102230973096230822308023079265292652826527230892309523094230932308623083265262310123100230982308423112231112311023109231072653023106231523103231042311326496224262299623029229412284722871228702640026399210332255321996212632125320873218562077820693262712274020647043422568261542615125879257852578425713256692534225335230950220800049230632306426519230442304223040230302309223077230742308523092308723108224242299122995229932299023012229882299720683006070053820710257832578225267approximate Pre-Illinois Episode till border