DESCRIPTION OF DIGITAL FILES FOR PRELIMINARY GEOLOGIC MAP OF THE BLACK MOUNTAIN AREA NORTHEAST OF VICTORVILLE, SAN BERNARDINO COUNTY, CALIFORNIA (U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT 2006-1347)

By Paul Stone

INTRODUCTION

The results of this preliminary map compilation of the geology of the Black Mountain area 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; a Portable 
Document Format (PDF) file of the geologic map and descriptive text; 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
bm.tar.gz; see section below titled, SOFTWARE UTILITIES.

ARC/INFO			Coverage		Contains 	
Interchange file

bm_geo.e00			bm_geo		Contacts, faults, and rock units
bm_str.e00			bm_str		Folds; attitudes and dip values
bm_beds.e00			bm_beds		Conglomerate beds
bm_sct.e00			bm_sct		Lines of geologic cross sections
bm_anno.e00			bm_anno		Geologic unit labels (with leaders) 

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		bm_geo.pat
Arc attribute tables		bm_geo.aat, bm_str.aat, bm_beds.aat,
					bm_sct.aat, bm_anno.aat
Point attribute table		bm_str.pat 


FILES FOR VIEWING AND PLOTTING

OF2006-1347.pdf			A Portable Document Format (PDF) file for viewing
					and plotting the geologic map at full scale.  The 
					map sheet includes the description of map units 
					and brief interpretive notes.  The plot is 
					approximately 36 x 36 inches in size.

METADATA

bm_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/of/2006/1347 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 bm.tar.gz			gzip -d bm.tar.gz (or use gzip 
to bm.tar					utility of choice)

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

Extract the Black Mountain		tar -xvof {path to tar file}/bm.tar
directory from the tar file		(or use tar utility of choice)

This process will create a directory, bm/, 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.  

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 file is accessed using Adobe Reader software, available free 
from the Adobe website http://www.adobe.com.  Follow instructions at the website 
to download and install the software.