Herzog, B.L.. B.J. Stiff, C.A. Chenoweth, K.L. Warner, J.B. Sievering, C. Avery 1994 20040331 map ISGS GIS Database GISDB_BEDGEO.IL_Bedrock_Topography_1994_Ln Champaign, Illinois Illinois State Geological Survey Scale is 1:500,000. This is the digital version of ISGS Map Series, Illinois Map 5. http://www.isgs.illinois.edu/ http://illinois.edu The Buried Bedrock Surface of Illinois map represents the first revision of the bedrock topography map since the second edition was published by the Illinois State Geological Survey (Horberg, 1957). The map is useful for the regional and statewide studies such as groundwater resource planning and geologic mapping. The data included on this map were compiled by many downhole logging and surface studies. This information was combined to revise the bedrock topography map for the entire state. Since some of the most extensive and productive aquifers in the state are located in thick glacial sediments of major buried bedrock valleys, special attention was given to data for known bedrock valleys. The revised map was published by the ISGS (Herzog et al, 1994) and much of the following text appears on the published map. The bedrock topography is shown as 50-foot (15-meter) contours of bedrock elevation above mean sea level (msl). Bedrock elevations range from less then 250 feet (76 meters) in southern Illinois to more than a 1000 feet (300 meters) in the northwestern part of the state. Several major bedrock valleys are found across the state. The greatest control for the present bedrock surface configuration was probably the preglacial surface configuration. The interpretations of bedrock topography have been modified since the 1950's. Horberg contoured his map with the philosophy that the bedrock surface map represented the preglacial topography modified by glacial erosion, which formed U-shaped valleys. The current map, showing narrow valley channels and bedrock knobs in wide channels, indicates complex preglacial and glacial erosion primarily from running water. The major valleys were formed before the minor valleys that appear as tributaries. Streams that formed during successive glaciations probably eroded to bedrock and produced the small tributary valleys to the main channels. The bedrock surface was less likely to be eroded as sediments accumulated during each successive glaciation. Applications are regional or statewide studies, preferably at a scale of 1:500,000. The Buried Bedrock Surface of Illinois will be useful in fields such as groundwater resource planning, engineering geology and earthquake hazard mapping. Data shown on this map were compiled from geologic data from drill holes, samples, surface observations and geophysical data from downhole logging and surface studies. The data are not appropriate as a geodetic, legal or engineering base. The data set was not and is not intended as a substitute for surveyed locations, such as can be determined by a registered Public Land Surveyor. Although useful in a GIS as a reference base layer for maps, the data set has no legal basis in the definition of boundaries or property lines. The dataset was transferred for storage into the ISGS Enterprise GIS (SDE) in March, 2004. At that time the edition number was changed from 1.0 to 20040331. 1994 publication date Complete Irregular -91.58050943 -87.38825182 42.49669441 36.9521143 none geology bedrock topography none Illinois ISGS information must be obtained directly from the ISGS or from an authorized distributor. Be aware that ISGS information obtained from an unauthorized third party may have been altered subsequent to original distribution, or may no longer be current. Any access to these data, Web sites, computer systems, electronic services, and electronic networks is governed by University and campus policies, in particular, but not limited to, the Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign, the ISGS Terms of Use document available at the ISGS Web site, and the University of Illinois Web Privacy Notice. Links to these are provided in the Cross References section. ISGS information is the property of and copyrighted by the Board of Trustees of the University of Illinois with all rights reserved.  University copyright policy is stated in the General Rules Concerning University Organization and Procedure, Article III, Section 4. A link is provided in the Cross References section. Individuals or entities may make fair use of copyrighted ISGS material, such as reproducing a single figure or table, or using a brief text quotation, without obtaining formal permission, but in all cases the Illinois State Geological Survey must be credited as the source of the material. To reproduce ISGS information beyond the fair use standard, permission must be obtained from the ISGS Information Office, 615 East Peabody Drive, Champaign, Illinois 61820, 217-333-4747, isgs@isgs.illinois.edu. License fees and a license agreement may be required, depending on the proposed usage. Any use of these data is governed by University and campus policies, in particular, but not limited to, the Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign, the ISGS Terms of Use document available at the ISGS Web site, and the University of Illinois Web Privacy Notice. Links to these are provided in the Cross References section. Map information is to be used at a scientifically and cartographically appropriate scale, that is, at a scale no greater than indicated on the map or as described in the documentation of the map or map data.  Map information is not appropriate for, and is not to be used as, a geodetic, legal, or engineering base. Map information has no legal basis in the definition of boundaries or property lines and is not intended as a substitute for surveyed locations such as can be determined by a registered Public Land Surveyor. The data do not replace the need for detailed site-specific studies. Please refer to the Distribution Information section. ArcSDE 9.1 on Oracle 10g http://www.isgs.illinois.edu http://www.vpaa.uillinois.edu/policies/web_privacy.cfm http://www.uillinois.edu/trustees/rules.cfm#sec34 http://www.fs.uiuc.edu/cam/CAM/viii/viii-1.1.html The published geological map (ISGS Illinois Map 5, 1994) was the source for feature attributes. Attribute code assignments were reviewed by both the ISGS and the USGS and are believed to be fully representative of the source document. When in coverage format, this data set was checked for complete chain-node topology (no dangling arcs, except where appropriate), boundary values appropriate for map projection and map units, and appropriate "fuzzy" tolerances. There are no known arc attribute values outside the appropriate value domains. This data set depicts the buried bedrock surface of Illinois. Areas where the bedrock surface is exposed at the surface are not shown (e.g. the northwest Illinois driftless area, and much of southern Illinois). Horizontal positional accuracy of this data with respect to the source map was verified by ISGS and USGS personnel by visual comparison (manual overlay) of source mylars and hard-copy plots. Arcs within one line-width of source mylars were deemed acceptable. Herzog, B.L.. B.J. Stiff, C.A. Chenoweth, K.L. Warner, J.B. Sievering, C. Avery 1994 map ISGS Illinois Map series 5 Champaign, Illinois Illinois State Geological Survey 500000 paper 1994 publication date none contour attributes (elevation values) Herzog, B.L.. B.J. Stiff, C.A. Chenoweth, K.L. Warner, J.B. Sievering, C. Avery 1994 map Champaign, Illinois Illinois State Geological Survey unpublished material 500000 mylar 1994 publication date none contour lines Anderson, R.C. 1980 report ISGS Circular 510 Champaign, Illinois Illinois State Geological Survey 35 p. not available paper 1980 publication date none not available Berg, R.C., J.P. Kempton, A. Stecyk 1984 report ISGS Circular 531 Champaign, Illinois Illinois State Geological Survey 69 p. not available paper 1984 publication date none not available Bristol, B.B. and P.R. Seaber 1973 report Champaign, Illinois Illinois State Geological Survey not available paper 1973 not available none not available Curry, B.B. and P.R. Seaber 1990 report Contract/Grant Report 1990-1 Champaign, Illinois Illinois State Geological Survey not available paper 1990 publication date none not available Greasse, A.M., R.A. Bauer, B.B. Curry, R.C. Vaiden, W.G. Dixon, Jr., J.P. Kempton 1988 report ISGS Environment notes 123 Champaign, Illinois Illinois State Geological Survey not available paper 1988 publication date none not available Heigold, P.C. and R.W. Ringler 1979 report ISGS Circular 507 Champaign, Illinois Illinois State Geological Survey 18 p. not available paper 1979 publication date none not available Horberg, L. 1950 report ISGS Bulletin 73 Champaign, Illinois Illinois State Geological Survey not available paper 1950 publication date none not available Horberg, L. 1957 map Champaign, Illinois Illinois State Geological Survey 500000 paper 1957 publication date none not available Hunt, C.S. and J.P. Kempton 1971 report ISGS Environmental Geology Notes 83 Champaign, Illinois Illinois State Geological Survey 42 p. not available paper 1971 publication date none not available Jacobs, A.M. (compiler) 1971 report ISGS Circular 465 Champaign, Illinois Illinois State Geological Survey 35 p. not available paper 1971 publication date none not available Kempton, J.P., W.H. Johnson, P.C. Heigold and K. Cartwright 1991 report Geological Society of America (GSA) Special Paper 285 p. 91 not available paper 1991 publication date none not available Kempton, J.P., W.H. Morse, and A.P. Visocky 1982 report Cooperative Groundwater/Resources Report 8 Champaign, Illinois Illinois State Geological Survey not available paper 1982 publication date none not available Kempton, J.P., R.W. Ringler, P.C. Heigold, K. Cartwright, V.L. Poole 1981 Environmental Groundwater/Resources Report 13 Champaign, Illinois Illinois State Geological Survey 36 p. not available paper 1981 publication date none not available Kempton, J.P. A.P. Visocky 1992 Cooperative Groundwater/Resources Report 13 Champaign, Illinois Illinois State Geological Survey 42 p. not available paper 1992 publication date none not available Kolata, D.R., T.C. Buschbach and J.D. Treworgy 1978 report ISGS Circular 505 Champaign, Illinois Illinois State Geological Survey Figure 2 not available paper 1978 publication date none not available Larsen, J.I 1973 report ISGS Circular 481 Champaign, Illinois Illinois State Geological Survey 43 p. not available paper 1973 publication date none not available Larson, D.R., B.L. Herzog, R.C. Vaiden, C.A. Chenoweth and R.C. Anderson 1994 report Champaign, Illinois Illinois State Geological Survey 43 p. not available paper 1994 publication date none not available Larson T.H. and V.L. Poole 1989 report ISGS Contract/Grant Report 1989-2 Champaign, Illinois Illinois State Geological Survey 51 p. not available paper 1989 publication date none not available Lineback, J.A. 1979 map ISGS map same as title Champaign, Illinois Illinois State Geological Survey 500000 paper 1989 publication date none not available Palmer, R.A. (compiler) 1983 report Geology, v 11 no. 9 p. 503-504 not available paper 1989 publication date none not available Piskin, K. and R.E. Bergstrom 1975 map and report ISGS Circular 490 Champaign, Illinois Illinois State Geological Survey 35 p. 500000 paper 1975 publication date none not available Richmond, M.R. and D.S. Fullerton 1986 Quaternary Science Review v5 p. 130 not available paper 1975 publication date none not available Walker W.H., R.E. Bergstrom and W.C. Walton 1965 report Cooperative Groundwater/Resources Report 3 Champaign, Illinois Illinois State Geological Survey 61 p. not available paper 1975 publication date none not available H. B. Willman, John C. Frye, Jake A. Simon, Kenneth E. Clegg, D. H. Swann, Elwood Atherton, Charles Collinson, Jerry Lineback, and T. C. Buschbach. 1967 map ISGS map same as title Capitol Heights, MD Williams and Heintz Map Corp. 500,000 mylar map 1967 publication date none not available Willman, H.B., and J.C. Frye 1980 map and report ISGS Circular 511 Champaign, Illinois Illinois State Geological Survey 23 p. 500000 paper 1975 publication date none not available Note: This entire section is taken directly from the published Buried Bedrock Surface map (Herzog et al, 1994). Horberg's work was updated by incorporating more detailed, published maps and unpublished data. This map was prepared for publication by combining computer techniques with traditional methods. 1994 Well log data from the ISGS files were entered into an ISGS computer database created for this project. Data compilation concentrated on areas where Horberg mapped bedrock valleys. More well information was available for the northern 35 counties, where many densely populated communities depend on groundwater supplies, than for the rest of the state. 1994 Well locations with bedrock elevation data plotted by computer at a scale 1:250000. Bedrock topography was manually contoured for separate maps of the northern, central, and southern parts of the state, then the maps were manually combined. Anomalous bedrock elevation data were rechecked with the original source and compared with other data for the area, Horberg's maps, and previously published regional local bedrock topography maps. Glacial margins are from Lineback (1979). The style of Horberg (1957) was followed by not contouring bedrock elevation beyond the glacial margin, except where the bedrock surface is overlain by thick river alluvium and outwash. Sizeable areas are shown where the bedrock surface within and beyond the glacial margin is within approximately 20 feet (6 meters) or less of the ground surface. Beyond the glacial margin, the bedrock surface may be covered by river alluvium, outwash, loess, or residuum. 1994 After the map was assembled by hand, local and regional bedrock topography maps, published since Horberg (1957), were incorporated into this bedrock topography map. Unlike the state map, the regional and local maps used all data available for the areas under study at the time of publication. These maps were modified with new data and spliced into the hand-contoured map. Locations of these maps are shown in an inset map (figure 1) on the published (hardcopy) version of this map. Sources of the regional maps are listed in the references. 1994 The contours were first hand-drafted onto a 1:250000-scale base map. The base included reference points at latitude/longitude degree intersections. The manually drafted contours and reference points were scanned to convert the line to digital format. Because of size limitations of the equipment, the map was scanned in eight parts. The resulting digital images were converted to a vector format, spatially referenced, edited, labeled with elevation values, and combined to form one map. 1994 This data has gone though several review steps. The published version of the Buried Bedrock Surface Map went through an internal review process prior publication in 1993. Others involved in the review include Beverly Herzog (ISGS), Cheri Chenoweth (ISGS) and Kelly Warner (USGS). 1994 Source coverage (bedtopo) converted to double precision and reprojected to GCS_NAD83 using Workstation ArcInfo 7.2.1. The features were imported into the ISGS SDE enterprise database following steps outlined in ISGS procedure GISDB_0009. Metadata updated. 11214300 A user reported that the contour value for OBJECTID = 938 was in error. It was 600 but should be 550. The value was corrected. The correction was done with SQL directly against the business table, rather than use SDE versioned editing. The SQL statement used was: update GISDB.IL_Bedrock_Topography_1994_Ln set contour = 550 where objectid = 938; 20041004 Vector String 2620 0.000000 0.000000 Decimal degrees NAD27 CLARKE1866 6378206.4 meters 294.98 Attribute items are in typical SDE feature class format. Those requiring additional explanation are: CONTOUR The elevation above msl in Lambert feet. Values range from 200 to 1000 with a contour interval of 50 feet. A value of zero (0) is used to indicate the state boundary or areas where bedrock is at or near the surface. none Information Office, Illinois State Geological Survey (ISGS), a division of the Institute of Natural Resource Sustainability (INRS) of the University of Illinois mailing and physical address

615 East Peabody Drive

Champaign Illinois 61820 USA 217-333-4747 217-785-0211 isgs@isgs.illinois.edu 8:00 a.m. - 4:30 p.m., Monday-Friday, U.S. Central Time Refer to the Legal Notices of Terms and Conditions of the University of Illinois Web Privacy Policy (there is a link in the Cross References section) for policy statements regarding the following: Disclaimer of Liability Disclaimer of Warranties and Accuracy of Data Disclaimer of Endorsement Disclaimer for External Links Disclaimer of Duty to Continue Provision of Data Security Choice of Law By obtaining these data you agree to the provisions of the University of Illinois Web Privacy Policy, regardless of the manner in which the information was obtained. The data are intended for use with GIS software. The ISGS uses ESRI ArcGIS software, however, ESRI formats can be imported into many different GIS software packages. It is expected that customers who obtain these data have the technical expertise to use GIS software. The ISGS does not provide software support of any kind. 20090224 Please refer to the Distribution Information section. FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time The access constraints as stated for the data apply also to the metadata. Refer to the Access Constraints section of the Identification Information section. The use constraints as stated for the data apply also to the metadata. Refer to the Use Constraints section of the Identification Information section. http://www.esri.com/metadata/esriprof80.html ESRI Metadata Profile