Glacial Drift in Illinois: Thickness and CharacterEntry ID: IGDNR_DRIFTTHK
Abstract: This is an SDE feature dataset showing drift thickness in Illinois. Data are originally from ISGS Circular 490 by Piskin and Bergstrom (1975), Plate 1. Contours (lines) are coded with thickness, and polygons (areas between contours) are coded with range of thickness. Nominal scale is 1:500,000.
Unconsolidated deposits, mainly glacial drift, overlie the bedrock surface in most of Illinois. Glacial ... drift ranges from less than a few feet to approximately 600 feet in thickness. The thickest drift occurs in major preglacial valleys cut into the bedrock and filled with glacial sediments. Regionally thick drift occurs in the N.E. portions of the state. The thinnest drift, less than 25 feet thick and intersected by numerous bedrock outcrops, occurs widely in southern and western portions of the State. Drift, as shown on this map, may include any of the following: unconsolidated deposits, glacial drift, Wisconsinan deposits, Illinoian deposits, till, glaciofluvial deposits, glaciolacustrine deposit, wind-blown deposits (loess).
Purpose: These data may be used to determine approximate depth to bedrock in regional areas of the state (eg. townships). The data are not of sufficient detail for use in determining drift thickness for specific locations. The data can be used for physical or environmental models of the state's unconsolidated geologic materials, eg. coupled with geophysical information, satellite imagery, air photos, ... hydrologic data, or other data in a Geographic Information System at a statewide scale of 1:500,000.
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.
Data Set Citation
Dataset Originator/Creator: Illinois State Geological Survey
Dataset Title: Glacial Drift in Illinois: Thickness and Character
Dataset Series Name: ISGS GIS Database
Dataset Release Date: 1994
Dataset Release Place: Champaign, Illinois
Dataset Publisher: Illinois State Geological Survey
Issue Identification: driftthk
Data Presentation Form: mapOnline Resource: http://clearinghouse.isgs.illinois.edu/data/geology/glacial-drift-t...
Paleo Temporal Coverage
Access Constraints none
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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 the appropriate
custodial division within 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. These data are not to be used for commercial profit.
Data Set Progress
Distribution Media: Online
Distribution Size: 164KB
Distribution Format: Arc/Info export format
Fees: No fees
Role: DIF AUTHOR
Role: TECHNICAL CONTACT
Email: stiff at geoserv.isgs.uiuc.edu
Illinois State Geological Survey 615 East Peabody Drive U.S.A.
Province or State: Illinois
Postal Code: 61820
Extended Metadata Properties
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Creation and Review Dates
Last DIF Revision Date: 2018-05-11