DESCRIPTION OF DIGITAL FILES FOR GEOLOGIC MAP OF THE SANTA ROSA 7.5' QUADRANGLE, SONOMA COUNTY, CALIFORNIA 

Database by Craig A. McCabe

INTRODUCTION

        This readme document serves to introduce and describe the digital files that are included in this publication. They are available for downloading at http://pubs.usgs.gov/of/2008/1009/ and include both Geographic Information System (GIS) software files (both raster and vector data) that are viewable with an Environmental Systems Research Institute (ESRI) compatible commercial GIS (or with ESRI’s ArcReader utility; a free map viewer with no editing capabilities) as well as Portable Document Format (PDF) files that are viewable with a reader or web browser plug-in available for free on the internet. Two download packages are available (see the section entitled “Open-File Report 2008-1009 Digital Contents” below for details) depending on the resources available to the user. For those interested only in a paper plot of the Open-File Report, please see the section entitled "Obtaining Paper Plots" below. 
        This digital map publication, generated from new mapping by the author, shows the general distribution of bedrock and surficial deposits in the Santa Rosa 7.5' quadrangle. Together with the accompanying geologic description pamphlet, it presents current knowledge of the geologic structure and stratigraphy of the area covered. The database identifies map units that are classified by general age and lithology following the stratigraphic nomenclature used by the U.S. Geological Survey. The scale of the source map limits the spatial resolution (scale) of the database to 1:24,000 or smaller. The content and character of the digital publication, as well as methods of obtaining the digital files, are described below. 

OPEN-FILE REPORT 2008-1009 DIGITAL CONTENTS 

The digital data for this Open-File Report consists of: 
1. A Geodatabase package that contains geologic vector and table data stored as data objects within an ESRI format personal geodatabase, raster data stored as ESRI format DRG-TIFF, an ESRI map document for use with ArcGIS 9.2 which allows full control of editing and rendering of the data sources, an ESRI published map document for use with ArcReader which allows viewing and querying of the source data along with metadata and an ArcGIS style for symbolizing the map. 
2. A Shapefile package that contains shapefiles exported from the personal geodatabase, and the same ESRI DRG-TIFF as in the Geodatabase package along with supporting files including metadata. Annotation layers are not included due to software limitations. 
3. PDF files of the map sheets and geology pamphlet.

Each package has been compressed into a single file (.zip extension) using WinZip, a freely downloadable compression software utility (download from http://www.winzip.com . Each compressed file will uncompress into a folder containing the associated files. 

If you: 
* Have access to ArcGIS 9.2, download the Geodatabase package and open the map document         (.mxd extension) from ArcGIS.
* Have access to ArcView 3.2 (or a GIS that can read shapefiles), download the Shapefile package. 
* Do not have access to a GIS but wish to view and query the data, download the Geodatabase package and open the published map document (.pmf extension) from ArcReader (free download from http://www.esri.com ). 
* Do not have access to a GIS and only wish to print the map sheet or parts of it, download the PDF package and open them from Adobe Reader 7.0 or later (free download from http://www.adobe.com). Note that each map sheet is approximately 36 x 54 inches and will require a large-format plotter. 


1) GEODATABASE PACKAGE 

Geodatabase data objects 	Description

sr_quat_cam.mdb 			An ESRI personal geodatabase with simple feature 					classes

Feature Classes 
    sr-poly 			A polygon feature class representing geologic 						units
 
    sr-line 			A line feature class representing the contacts and 					faults of the geology

    sr-ls				A line feature class representing landslide 						movement direction and unit leaders

    sr-xsec				A line feature class representing lines of cross-					section

    sr-mag				A line feature class representing magnetic 						contours

    sr-grav				A line feature class representing gravity contours

    sr-struc			A point feature class representing bedding 						measurements
 
    sr-tephra			A point feature class representing chemistry data

    sr-geochron			A point feature class representing radiometric 						data

    sr-text				A text feature class representing fault throw 						direction 

    sr-strucAnno			An annotation feature class (feature-linked) 						representing the dip of beds

    sr-polyAnno			An annotation feature class (feature-linked) 						representing map unit symbols of the geologic 						units

Map document files
 
    santarosa.mxd 	Map document created in ArcGIS 9.2 containing the data 				rendering and symbolization information that was used in 				the production of the Open-File Report. For this release, the layers 	were grouped logically and given aliases in order to be more usable 

    santarosa.pmf 	Published map document created from santarosa.mxd for 				use with ArcReader. It contains all of the same 					rendering and symbolization information that is in the 				original .mxd. Features may be queried with the identify 				tool in the same way they could in the .mxd, but there 				are no editing capabilities with this utility

    santarosa.style 	Custom style file used to symbolize lines, 						polygons, and points

    santarosa_drg.tif 	DRG base of USGS topographic map at 400 dpi 

    metadata.html 	Metadata created in ArcCatalog for this map 



2) SHAPEFILE PACKAGE 

Shapefiles 			Description

sr-poly.shp			A polygon shapefile of the sr-poly feature class 					exported from the geodatabase (see Geodatabase Package 				above)
 
sr-line.shp 		A line shapefile of the sr-line feature class exported 				from the geodatabase (see Geodatabase Package above)

sr-ls.shp			A line shapefile of the sr-ls feature class exported 					from the geodatabase (see Geodatabase Package above)

sr-xsec.shp			A line shapefile of the sr-xsec feature class exported 				from the geodatabase (see Geodatabase Package above)

sr-mag.shp			A line shapefile of the sr-mag feature class exported 				from the geodatabase (see Geodatabase Package above)

sr-grav.shp			A line shapefile of the sr-grav feature class exported 				from the geodatabase (see Geodatabase Package above)

sr-struc.shp		A point shapefile of the sr-struc feature class exported 				from the geodatabase (see Geodatabase Package above)

sr-tephra.shp		A point shapefile of the sr-tephra feature class 					exported from the geodatabase (see Geodatabase Package 				above)

sr-geochron.shp		A point shapefile of the sr-geochron feature class 					exported from the geodatabase (see Geodatabase Package 				above)

sr-text.shp			A text shapefile of the sr-text feature class exported 				from the geodatabase (see Geodatabase Package above)

Map document files 
   santarosa.style 		Custom style file used to symbolize lines, 						polygons, and points. 

   santarosa_drg.tif		DRG base of USGS topographic map at 400dpi 

   metadata.html			Metadata created in ArcCatalog for this map 


3) PORTABLE DOCUMENT FORMAT 

Files					Description

OFR2008-1009 sheet1.pdf 		A PDF file containing the geologic map
 
OFR2008-1009 sheet2.pdf		A PDF file containing an cross-sections, tables, 							and figures

OFR2008-1009 sheet3.pdf	A PDF file containing an isostatic gravity map and and an aeromagnetic map

OFR2008-1009 pamphlet.pdf	A PDF file of the geology pamphlet 

OBTAINING THE DIGITAL DATA 

TO OBTAIN THE FILES FROM THE U.S. GEOLOGICAL SURVEY WEB PAGES:  The U.S. Geological Survey supports a set of graphical pages on the World Wide Web. Digital publications (including this one) can be accessed via these pages. The location of the main Web page for the entire U.S. Geological Survey is http://www.usgs.gov . The Web server for digital publications is http://pubs.usgs.gov. To access files for this Open-File Report, go to http://pubs.usgs.gov/of/2008/1009/.


DIGITAL COMPILATION 
Several different feature classes were generated within a geodatabase during the construction of the Santa Rosa quadrangle geologic map. The topographic base map remains as a digital raster graphic (DRG) and is overlain on the geology feature class in ArcMap at a 60% transparency level. Some custom menus were used to project, transform, edit, tag, and build points in the map. A digital layout or map collar was made with Adobe Illustrator. The map was exported from the layout view in ArcMap as an Adobe Illustrator file and added to a single Adobe Illustrator file that also contained the description of map units, correlation of map units, cross sections, and an index map. Differences between the maps as they appear in the final map sheet and as they appear in the either the .mxd or .pmf files represent changes made in the Adobe Illustrator file to the symbology only and do not reflect any changes in the actual source data. The map is in UTM projection, zone 10, meters, and 1:24,000 scale. The explanatory geology pamphlet was saved to PDF from Microsoft Word.

BASE MAP 
The base map for the digital compilation is a Digital Raster Graphic (DRG) of the U.S. Geological Survey, 1:24,000-scale topographic map of the Santa Rosa 7.5' quadrangle (1980), which has a 20-foot contour interval. The image inside the map neatline is georeferenced to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map. The base map layer is a digital image, but no information other than location is attached to the lines. The base map is provided for reference only. 

SPATIAL RESOLUTION 
Uses of this digital geologic map should not violate the spatial resolution of the data. Although the digital form of the data removes the constraint imposed by the scale of a paper map, the detail and accuracy inherent in map scale are also present in the digital data. The fact that this database was edited at a scale of 1:24,000 means that higher resolution information is not present in the dataset. Plotting at scales larger than 1:24,000 will not yield greater real detail, although it may reveal fine-scale irregularities below the intended resolution of the database. Similarly, where this database is used in combination with other data of higher resolution, the resolution of the combined output will be limited by the lower resolution of these data. 

ACKNOWLEDGMENTS 
We thank Zenon Valin for a digital review of this database.