The data include name and modifier for geologic unit, map symbol, and a qualitative statement on the relative accuracy of the mapped location of unit boundaries.
The data were published in 1999 on an ISGS Illinois Geologic Quadrangle entitled Surficial Geology Map, Alton Quadrangle (Illinois Portion) Madison County, Illinois by David Grimley. These data do not include all the information on the published map. Refer to the published map for a complete explanation of the Quaternary geology of the Alton quadrangle.
The nominal scale is 1:24,000.
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.
These data should not be used at scales greater than 1:24,000.
Data automation: D. Grimley, C. Abert, D. Nelson GIS processing: D. Grimley, C. Abert, D. Nelson Documentation: D. Nelson QA/QC: D. Nelson
Data set was DESCRIBED and coverage files listed to determine the feature types present. In this data set, the following feature types were found and checked: polygons, arcs, labels, and nodes. The presence of spatial indices was also checked.
For PAT and AAT files, each ITEM was checked for the following:
- DOMAIN of allowable values - adherence of values to the DOMAIN - definition of ITEMS - requirement of all UNIQUE values for an item - logic of ITEMS REDEFINED over other ITEMS - length of ITEM name as regards conversion to shape fileBUILD statuses of data sets were checked, as were LABELERRORS and NODEERRORS (where appropriate), and PROJECTION definition.
The presence of a DBLBND file was verified.
The presence and location of TICS were checked.
Polygon and chain-node topology present. There are no dangling arcs. There is one polygon label per polygon, except for universe polygon. Boundary values appropriate for map projection and map units. "Fuzzy" tolerance is zero and therefore meaningless. Unneeded .AAT and .PAT items were dropped and tics were replaced. Coverage was DISSOLVED to join polygons with like attributes. COVER-ID values were recalculated to be unique. There are no attribute values outside the appropriate domains.
Polygon attributes:
GEOUNIT: The name(s) of the geologic unit
UNITSUFFIX: Additional text modifying the geologic unit
MAPSYMBOL: The abbreviation for the geologic unit from the published map
SYMBOL: Numeric designation that relates to an ArcView 3x legend file (.avl)
Line attributes:
CONTACT: A qualitative statement of the positional accuracy of the placement of a unit boundary
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.