Hunton Limestone Megagroup Ancell Group Prairie du Chien Group Ironton-Galesville Sandstone Elmhurst-Mt. Simon Sandstone
The scale of these data is 1:500,000.
These data are appropriate for use in regional thematic analysis. The data are not appropriate as a geodetic, legal or engineering base. The datasets were not and are not intended as a substitute for surveyed locations, such as can be determined by a registered Public Land Surveyor. Although useful in a GIS, the data have no legal basis in the definition of boundaries or property lines.
The source coverage (edition 2.0) was entirely reconstructed from the source hand-drafted map, making the previous version (coverage edition 1.0) obsolete. This edition retains the edition 2.0 data.
Some information used to compile this map was obtained from well log data on file at the Illinois State Geological and Water Surveys. A variety of well/boring data were used, including:
water wells oil wells (active and abandoned) gas wells (active and abandoned) Secondary and Tertiary oil recovery wells air injection wells service wells waste disposal wells observation wells (disposal sites) observation wells (water resources) gas storage operational wells water test holes coal test holes mineral test holes structure test holes stratigraphic test holes engineering test holes
Links to these are 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, email@example.com. License fees and a license agreement may be required, depending on the proposed usage.
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.
The features were imported into the ISGS SDE enterprise database following steps outlined in ISGS procedure GISDB_0009.
Attributes COUNT-FED-FIPS and SYMBOL were dropped. They were unnecessary items leftover from previous processing.
CODE - Discriminates polygon on basis of water quality 0 - Major bedrock aquifers containing more than 10,000 mg/L total dissolved solids 1 - Major bedrock aquifers containing from 2,500 to 10,000 mg/L total dissolved solids 2 - Major bedrock aquifers containing less than 2,500 mg/L total dissolved solids
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
Illinois Natural Resources Geospatial Data ClearinghouseGenerated by mp version 2.8.25 on Wed Apr 08 08:29:04 2009