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.
In April 2004 the source coverage was transitioned to storage in an Oracle RDBMS using the ArcSDE geodatabase model. The result (this version) is designated edition 20040408. Prior to this time the feature classe was stored as a coverage in the ISGS GISDB archive.
Edition 2.0 differed from edition 1.0 in that some sinkhole polygons in northwestern Illinois were deleted after field examination suggested that the depressions may have an origination other than by sinkhole formation. In addition, additional sinkhole area polygons were added in southern, southwestern, and western Illinois.
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, firstname.lastname@example.org. 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.
Source map underwent ISGS peer review. Line accuracy was checked by overlay of digital print-outs to original compilation maps. Lines within one line-width of source maps were deemed acceptable. Attribute accuracy was verified against source maps.
Prior to import, the spatial reference of the data set was changed to Geographic, decimal degrees, NAD83 in double precision.
Also at this time, this metadata file was updated.
KARST - a value of "y" indicates polygon represents a karst area
SQMILES - area of the polygon in square miles
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 Thu Apr 02 09:54:11 2009