U.S. Geological Survey 
Open-File Report 97-93
Springdale, Nevada 7.5’ Quadrangle
1:24,000-Scale Geologic Map Database
On-Line User Instructions and Information
(04/97)

The Springdale geologic database was initially developed in Geographic Resource 
Analysis System (GRASS), a public-domain Geographical Information System (GIS).  
The database was imported into ARC/INFO for final editorial changes and output 
formatting.  The geologic data files comprising this database are available here in ASCII 
(ARC/INFO UNGENERATE) and ARC/INFO EXPORT (non-compressed) formats.  
These various data files and several additional files are bundled together in the tar file 
spgdale.tar that accompanies this readme file.  After uncompressing the tar file (see 
instructions below), the ASCII and EXPORT data files are located in the spgdale 
directory under the ascii and export subdirectories.  The Springdale database consists of 
five map layers or coverages:  (1) polygons, (2) faults, (3) structatts, (4) topo, and (5) 
base.  ASCII files having the extensions .pol, .lin, .lab, and .txt contain the polygon line, 
non-polygon line, point, and attribute data, respectively.  All EXPORT files have the 
extension .e00.  Metadata for the polygon, faults, structatts, and topo map 
layers/coverages are found in the polymeta.txt, fltsmeta.txt, structmeta.txt, and 
topometa.txt ascii text files, respectively, located in the metadata subdirectory.  Postscript 
versions of these metadata files have the extension .ps.  The metadata files include 
definitions of map feature attribute codes used in the map database. A description of map 
units and other informative text are located in the files mapunits.txt (ascii text) and 
mapunits.ps (Postscript), which are located in the maptext subdirectory.  An ARC/INFO 
graphics file (spgdale.gra) and a plot file (spgdale.rtl), which are included for color, hard-
copy output of the geologic map, are located in the plot subdirectory.  The resulting plot 
includes a correlation of map units, two geologic cross sections, an explanation of map 
symbols, and a location map.  
In displaying the geologic compilation it is important to note that the map data set 
is considered accurate when depicted at a scale of about 1:24,000; displaying the 
compilation at scales significantly larger than this may result in apparent distortions and 
(or) mislocations of the data.

Uncompressing Tar File  

	The data file was compressed with the GNU utility gzip.  This utility is available 
from any of the GNU source sites.  Versions of the software are available for UNIX 
systems, PCs running DOS, and DEC VMS systems.  A “tar” utility is also available for all 
three systems.  The command sequences shown below are in UNIX “C” shell (csh).  The 
sequences are the same for other operating systems, but the form of the commands are 
different.  
To uncompress the data enter:  
	UNIX% gunzip spgdale.tar
To access the data, enter:
	UNIX% tar vxf spgdale.tar
The data will then be available under the subdirectories indicated above.  

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Geologic and technical inquires should be directed to the database manager:  

Scott Minor 
U.S. Geological Survey
P.O. Box 25046, MS 913
Denver, CO  80225

E mail:  sminor@usgs.gov

(303)236-0303 
FAX (303)236-0214