THESE DATA SHOULD NOT BE USED AT MAP SCALES LARGER THAN 1:100,000.
During the analog-to-digital conversion process a few errors were discovered on the original analog map. An empty unit [no fill, no label] needed to be identified; an area which should have been open water was printed as part of an adjacent geologic unit. These errors were corrected in the Geologic Unit Areas and Geologic Line Features. Any discrepancies between open-water areas of the digital hydrography file and the printed map were coded to match the original publication. Arrows appear on the map, but are not described in the explanation. These arrows indicate 'direction of flow of premodern streams.' This information was added to the 'MapText' field of Geologic Point Features and to the metadata for that feature class.
On the original map, the Powers Bluff chert fan was represented by dashed lines defining the axis and margins of the feature. In the digital data, the chert fan was represented by a single polygon feature, with lateral boundaries coinciding with the margin lines on the map.
A film positive of the scribecoat used to produce the original linework, without shorelines, was scanned and saved as a black-and-white tif image (wd_pl_lns_nb.tif). The TIFF image was then registered to Wisconsin Transverse Mercator NAD 1983 HARN (WTM 83/91) coordinates using ESRI ArcGIS software, referencing 1:100,000-scale county boundary corners in WiDNR 1998. The resulting file was used when vector-tracing the linework in ArcMap.
During the analog-to-digital conversion process a few errors were discovered on the original analog map. An empty unit [no fill, no label] needed to be identified; an area which should have been open water was printed as part of an adjacent geologic unit. These errors were corrected in the Geologic Unit Areas and Geologic Line Features. Any discrepancies between open-water areas of the digital hydrography file and the printed map were coded to match the original publication. Arrows appear on the map, but are not described in the explanation. These arrows indicate 'direction of flow of premodern streams.' This information was added to the 'MapText' field of Geologic Point Features and to the metadata for that feature class.
On the original map, the Powers Bluff chert fan was represented by dashed lines defining the axis and margins of the feature. In the digital data, the chert fan was represented by a single polygon feature, with lateral boundaries coinciding with the margin lines on the map.
THESE DATA SHOULD NOT BE USED AT A SCALE LARGER THAN 1:100,000.