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Title: Geologic map of north-central Nevada
Author: John H. Stewart and John E. Carlson
Year: 1976
Series: Map 50z
Version:
Format: digital file only, 514 MB, zipped (includes PDF, 43 x 41 inches, full color)
Scale: 1:250,000
Regional geologic map showing 66 units; on topographic base with township and range grid; description of stratigraphic units mapped, sources of data by county, and references. Prepared in cooperation with the U.S. Geological Survey.
Order as M050 for the paper version (see "Related items" on this page for link).
About the Digital Files
From ReadMe file (April 29, 2015)
This directory contains the digital version of Map 50.
Please read the METADATA for detailed information on the geology in the METADATA directory. The METADATA for the USGS files (DRGs) can be found on the FGDC metadata clearinghouse (http://www.fgdc.gov).
This digital conversion project was undertaken by the Nevada Bureau of Mines and Geology in cooperation with the U.S. Geological Survey STATEMAP Program.
Folders Containing Files
m050z
|\data
| |\geodatabase (contains the ESRI geodatabase files for the map)
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| |\images (contains different types of images)
| |\DRG (USGS Digital Raster Graphics file of the area mapped)
| |\georeferenced (georeferenced map that was converted to GIS)
| |\Original (original paper map)
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| |\layerfiles (ESRI ArcGIS layer files of each layer in the table of contents of the ArcMap MXD file)
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| |\shapefiles (ESRI shape files for each layer in the ArcMap table of contents of the ArcMap MXD file)
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| \docs (metadata folder)
| |\metadata (contains the metadata as a text file (.txt) for:
| | Geodatabase
| | FeatureDataSet
| | Each FeatureClass in the Geology FeatureDataSet
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|\maps (contains the final ESRI ArcGIS 9.3.1 ArcMap MXD file, and PDF of final map)
The symbol and image files listed above contain graphic symbol information about associated line, point, and polygon features found on the published map but that may not have been fully identified in the present format of the feature line, point, or polygon attribute file. The layer files are provided here for use with the geologic map digital conversion as an aid to a graphic presentation of the full data set. The files can be utilized in ESRI ArcGIS 9.3 sp1 version.
Conversion Process
The original paper map that had been scanned on a large format table scanner, then the .tiff image was georeferenced using 4 reference points. Then, the map was digitized using ArcGIS ArcMap 9.3.1 for all features (lines, points, and cross sections). Then, polygons (GeoPolys) were created from the lines (GeoLines) and points (GeoPoints) to define the geologic unit polygons. Other point features on the printed map were digitized as points (GeoPoints) and defined using a definition query to define the type of point. Line errors were checked using two Topology rules: Lines Must Not Have Dangles, Lines Must Not Have Pseudo Nodes. The features were digitized in real world coordinates with the projection of: UTM projection, units in meters, zone 11, and a datum of NAD83. Polygon units (GeoPoints) were digitized and attributed in ArcGIS 9.3.1 and joined to the domain database. All work was checked for accuracy by NBMG staff members other than the person who digitized the work.
Original Product Code: M50 dox
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