Illinois State Geological Survey 1994 20040331 vector digital data ISGS GIS Database GISDB_BEDGEO.IL_Bedrock_Valleys Champaign, Illinois Illinois State Geological Survey The map scale is 1:500,000 This feature class shows continuous lines representing the lowermost elevations/locations of (buried) bedrock valleys in the state of Illinois. Scale is 1:500,000. Several major bedrock valleys are found across the state. The greatest control for the present bedrock surface configuration was probably the preglacial surface configuration. 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. These data were derived from the Buried Bedrock Surface of Illinois (GISDB_BEDGEO.IL_Bedrock_Topography_1994_Ln). Applications are regional or statewide studies, preferably at a scale of 1:500,000. Bedrock valley data can be used in conjunction with the buried bedrock surface information, which will be useful in such fields as groundwater resource planning, engineering geology and earthquake hazard mapping. 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. Recent updates to the data: In March 2004 edition 1.0 of the data set was transitioned to storage in an Oracle RDBMS using the ArcSDE geodatabase model. The result (this version) is designated Edition 20040331. 1994 publication dates of digital sources Complete None planned -91.5826823 -87.38401652 42.49563968 36.95351896 none geology bedrock valley Illinois basin none Illinois none Tertiary Cretaceous Pennsylvanian Mississippian Devonian Silurian Ordovician Cambrian none Reproduction or redistribution of copyrighted digital data sets or products derived therefrom outside of licensee's organization or entity is expressly forbidden. The only exception is redistribution to consultants working for the licensee, and then only for purposes, related to work for the licensee. Such consultants may not further reproduce or redistribute these data sets. None of these data shall be electronically duplicated on magnetic or optical media for use by others, in whole or in part, without permission of DNR. Any hardcopies utilizing DNR data sets shall clearly indicate their source. If the licensee has modified the data in any way they are obligated to describe the types of modifications they have performed on the hardcopy map. Licensee specifically agrees not to misrepresent DNR data sets, nor to imply that changes they made were approved by DNR. Please refer to distribution information. ArcGIS 9.1 on Windows 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. This data set depicts the buried bedrock valleys of Illinois. Only major valleys are included. Although this version has updated the major valleys since Horberg (1950), that source also shows smaller-scale tributary valleys which are not included in this dataset. 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 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. 500000 online 1994 publication date none linework and attributes 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 stable-base material 1994 publication date none contour lines Horberg, L. 1950 report ISGS Bulletin 73 Champaign, Illinois Illinois State Geological Survey not available paper 1950 publication date none not available Initial information was digitized from ISGS Bulletin 73. Unknown Updates to information were made corresponding to the creation of ISGS Illinois Map Series Plate 5. Refer to Process Step Entries for GISDB_BEDGEO.IL_Bedrock_Topography_1994_Ln for detailed information about creation of the source data set. 1994 The source coverage data for the feature classes were reprojected from the customary ISGS Lambert projection, NAD27 to geographic coordinates, NAD83, double-precision. The line features were imported into the ISGS SDE enterprise database, following steps outlined in ISGS procedure GISDB_0009. The source coverage was bedval. The annotation feature class was imported into SDE from the source coverage using the method in an article entitled Converting Annotation from Coverage to Geodatabase Format (Colin Childs, ArcUser Magazine, October-December 2001, pp. 22-23) and the companion tutorial (referenced in the article.) Prior to using the steps in the tutorial, a TAT coverage file had to be generated for the coverage. This was done in ArcInfo Workstation 7.2.1 with the following commands. Arc: copyfeatures bedval anno bedval anno.anno Arc: build bedval annotation.anno 20040331 Vector String 55 0.000001 0.000001 Decimal degrees North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 IL_Bedrock_Valleys_Ln FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Coordinates defining the features. NAME File attribute items are in typical SDE feature class format. The following arc items require additional explanation: NAME - name of bedrock valley 1 - ancient Mississippi (Lower and Middle Illinois and Princeton) 2 - Mahomet (Teays) 3 - Kaskaskia 4 - Paw Paw and Rook 5 - Troy 6 - Pecatonica 7 - Onarga 8 - Little Wabash 9 - Embarras 10 - Skillet Fork 11 - Saline 12 - Big Muddy 13 - Macoupin 14 - Cache 200 - Carthage, Lower Spoon, Ticona, Danvers, Middletown, Pesotum, Danville 300 - Kempton and Chatsworth 400 - Kirkwood, Athens, Wyoming, plus four unnamed tributary channels (Pecatonica [2], Rook [1], Danville [1]) 999 - state boundary Annotation features are included to display the bedrock valley name. none Illinois State Geological Survey, Bedrock Geology Section mailing and physical address

615 East Peabody Drive

Champaign Illinois 61820 USA 217-333-4747 217-785-0211 isgs@isgs.uiuc.edu 8:00 a.m. - 4:30 p.m., Monday - Friday, U.S. Central Time The Illinois Department of Natural Resources (DNR) provides these geographic data "as is." DNR makes no guarantee or warranty concerning the accuracy of information contained in the geographic data. DNR further makes no warranties, either expressed or implied as to any other matter whatsoever, including, without limitation, the condition of the product, or its fitness for any particular purpose. The burden for determining fitness for use lies entirely with the user. Although these data have been processed successfully on computers of DNR, no warranty, expressed or implied, is made by DNR regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty. In no event shall the DNR have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including, but not limited to, any loss of profits arising out of use of or reliance on the geographic data or arising out of the delivery, installation, operation, or support by DNR. The data are intended for use with GIS software. The ISGS uses ESRI ArcGIS software, however, the ESRI shapefile format can be imported into many different GIS software packages. It is expected that customers who order this data have the technical expertise to use GIS software. The ISGS does not provide software support of any kind. 20061017 Please refer to the distribution information. FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time None None http://www.esri.com/metadata/esriprof80.html ESRI Metadata Profile