DESCRIPTION OF DIGITAL FILES FOR GEOLOGIC MAP OF THE CERRO GORDO PEAK 7.5’ 
QUADRANGLE, INYO COUNTY, CALIFORNIA

By Zenon C. Valin and Paul Stone

INTRODUCTION

The results of this mapping of the geology of the Cerro Gordo Peak quadrangle 
are presented as a digital geologic map database.  This document describes the 
types and contents of files comprising the database.  Information on how to 
extract and plot the map also is provided.

This publication includes ARC/INFO (Environmental Systems Research Institute, 
http://www.esri.com) version 8.1.2 coverages and associated tables; Portable 
Document Format (PDF) files of the geologic map (which includes two structural 
cross sections) and an accompanying geologic pamphlet; and a text file of FGDC- 
compliant metadata for the report.
 
GEOLOGIC MAP DATABASE FILES AND ASSOCIATED FILES

All files listed in this section are in a compressed tar file named
SIM2851.tar.gz; see section below titled, SOFTWARE UTILITIES.

ARC/INFO			Coverage		Contains 	
Interchange file

cerro_geo.e00		cerro_geo		Contacts and faults
cerro_str.e00		cerro_str		Folds; attitudes and dip values
cerro_anno.e00		cerro_anno		Geologic unit labels (with leaders);
							fault names
cerro_sample.e00		cerro_sample	Sample localities
cerro_xs.e00		cerro_xs		Cross-section lines

The directory, info/, is produced in the process of importing interchange files 
to ARC coverages in ARC/INFO.  The info/ directory contains:

Polygon attribute table		cerro_geo.pat
Arc attribute tables		cerro_geo.aat, cerro_str.aat, cerro_xs.aat
					cerro_anno.aat
Point attribute tables		cerro_str.pat, cerro_sample.pat

Tar file also includes:

import.aml				An ARC/INFO Arc Macro Language file for importing
					the above coverages

FILES FOR VIEWING AND PLOTTING
       
SIM2851_map.pdf			A Portable Document Format (PDF) file for viewing
					and plotting the geologic map at full scale.  The
					plot is approximately 36 x 42 inches in size.

SIM2851_pamphlet.pdf		A Portable Document Format (PDF) file for viewing
					and printing a pamphlet that accompanies the map.
					The pamphlet contains a geologic interpretation
					and the description of map units.

METADATA

cerro_met.txt			Federal Geographic Data Committee (FGDC) compliant
					metadata file derived from the digital database

SOFTWARE UTILITIES

Files that have the .gz file extension were compressed using gzip.  Gzip 
utilities are available free of charge via the Internet at the gzip home page, 
http://www.gzip.org.

The data package is additionally bundled into a single tar (tape archive) file.  
The individual files must be extracted using a tar utility, available free of 
charge via the Internet through links on the Common Internet File Formats page, 
http://www.matisse.net/files/formats.html.  One such utility is WinZip, 
available at http://www.winzip.com (WinZip can also decompress files).

HOW TO OBTAIN THE DIGITAL FILES

The digital files constituting the geologic map database of this report may be 
obtained via the Internet from the U.S. Geological Survey publications website.  
Go to the web page at http://pubs.usgs.gov/sim2004/2851 and follow the 
directions to download the files.

EXTRACTING THE GEOLOGIC MAP DATABASE FROM THE TAR FILE

After downloading the files, they must be uncompressed using a gzip utility such 
as gzip itself or WinZip.  The data files must then be extracted using the 
appropriate tar utility.

To do this					Type this at the Unix command prompt

Uncompress SIM2851.tar.gz		gzip -d SIM2851.tar.gz (or use gzip utility
to SIM2851.tar				of choice)

Go to the directory that will		cd local_directory
hold the directory cerro/ (if 
different from local_directory)

Extract the Cerro Gordo Peak		tar -xvof {path to tar file}/SIM2851.tar
directory from the tar file		(or use tar utility of choice)

This process will create a directory, cerro/, that contains the ARC/INFO 
interchange files and supporting files.

CONVERTING THE ARC/INFO EXPORT FILES

ARC interchange (.e00) files are converted to ARC coverages using the ARC 
command IMPORT with the option COVER.  To ease conversion and maintain naming 
conventions, we have included an ASCII text file in ARC Macro Language that will 
convert all of the export files in the database into coverages and create the 
associated INFO directory.  With the workspace set to the directory containing 
the ARC export files, from the ARC command line type:

Arc: &run import.aml

ARC interchange files also can be read by some other Geographic Information 
Systems.  Please consult your GIS documentation to see if you can use ARC 
interchange files and to determine the procedure for importing them.

PORTABLE DOCUMENT FORMAT (PDF) FILES

The PDF files are accessed using Adobe Acrobat Reader software, available free 
from the Adobe website http://www.adobe.com.  Follow instructions at the website 
to download and install the software.  Acrobat Reader contains an on-line manual 
and tutorial.