DESCRIPTION OF DIGITAL FILES FOR GEOLOGY, TEPHROCHRONOLOGY, RADIOMETRIC AGES, 
AND CROSS SECTIONS OF THE MARK WEST SPRINGS 7.5' QUADRANGLE, SONOMA AND NAPA 
COUNTIES, CALIFORNIA

By V.R.G. Levin, Z.C. Valin, R.S. Nicholson, and R.E. Stamski


ISBN:  0-607-94088-3

INTRODUCTION

The results of this mapping of the geology of the Mark West Springs 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 two map sheets 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
SIM2858.tar.gz; see section below titled, SOFTWARE UTILITIES.

ARC/INFO                    Coverage          Contains
Interchange file

mws-geo.e00               mws-geo          Faults, depositional contacts, and
                                           rock units
mws-str.e00               mws-str          Folds; attitudes and dip values
mws-hyd.e00               mws-hyd          Hydrothermal alteration units
mws-pnt.e00               mws-pnt          Point locations
mws-lds.e00               mws-lds          Directional landslide arrows
mws-smb.e00               mws-smb          Strike and dip information associated
                                           with faults, including arrows and bar
                                           and ball symbols
mws-tph.e00               mws-tph          Tephra and geochronology sample
                                           locations

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

Polygon attribute tables      mws-geo.pat, mws-hyd.pat
Arc attribute tables          mws-geo.aat, mws-str.aat, mws-lds.aat
Point attribute tables        mws-str.pat, mws-pnt.pat, mws-smb.pat, mws-tph.pat

Other files:

SIM2858-readme.txt            This document (ASCII text file)
import.aml                    An ARC/INFO Arc Macro Language file for importing
                              the above coverages

FILES FOR VIEWING AND PLOTTING

SIM2858-sheet1.pdf            A Portable Document Format (PDF) file for viewing
                              and plotting sheet 1 at full scale.  The
                              plot is approximately 36 x 48 inches in size.

SIM2858-sheet2.pdf            A Portable Document Format (PDF) file for viewing
                              and plotting sheet 2 at full scale.  The
                              plot is approximately 36 x 48 inches in size.

SIM2858-pamphlet.pdf          A Portable Document Format (PDF) file for viewing
                              and printing a geologic pamphlet that accompanies
                              the map.

METADATA

SIM2858-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/sim/2004/2858 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 SIM2858.tar.gz          gzip -d SIM2858.tar.gz (or use gzip utility
to SIM2858.tar                     of choice)

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

Extract the Mark West Springs      tar -xvof {path to tar file}/SIM2858.tar
directory from the tar file        (or use tar utility of choice)

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

CONVERTING THE ARC/INFO INTERCHANGE 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.