Geologic Map and Map Database of Eastern Sonoma and Western Napa Counties, California By R.W. Graymer, E.E. Brabb, D.L. Jones, J. Barnes, R.S. Nicholson, and R.E. Stamski Pamphlet to accompany SCIENTIFIC INVESTIGATIONS MAP 2956 2007 U.S. Department of the Interior U.S. Geological Survey Digital Publication and Database Description Introduction This publication includes, in addition to cartographic and text products, geospatial (GIS) databases and other digital files. These files are published on the Internet through the U.S. Geological Survey publication web site (http://pubs.usgs.gov). The database files are particularly useful because they can be combined with any type of other geospatial data for purposes of display and analysis. The other files include digital files that support the databases, and digital plot files that can be used to display and print the cartographic and text products included in this publication. Following is the digital publication and database description. It contains information about the content and format of the digital geospatial databases used to create this digital geologic map publication. This information is not necessary to use or understand the geologic information in the map and preceding geologic description. This chapter mostly contains information useful for those who intend to use the geospatial databases. However, it also contains information about how to get digital plot files of the map and geologic pamphlet via the Internet, information about how the map sheet and pamphlet were created, and information about getting copies of the map sheet and text from the U.S. Geological Survey. In addition, in 1999, the USGS adopted policies regarding revision of publications, introducing the concept of version numbers similar to those used in the computer industry. The following chapter contains information about the version system and about how to access a revision list explaining changes from version 1.0, if any have been made. The digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution and orientation of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (eswnsim.txt, eswnsim.pdf, or eswnsim.ps), the database provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:62,500 or smaller. The content and character of the database, as well as three methods of obtaining the database, are described below. For those who don't use digital geologic map databases For those interested in the geology of the mapped area who do not use an ARC/INFO compatible Geographic Information System (GIS), we have provided two sets of plotfiles (PostScript format and another in Adobe Acrobat PDF format); each set contains an image of a geologic map sheet and explanation, and an explanatory pamphlet (see the sections "PostScript plot files" and "PDF plot files" below). Those interested who have computer capability can access the plot file packages in any of the three ways described below (see the section "Obtaining the digital database and plotfile packages"). However, it should be noted the plot file packages do require gzip and tar utilities to access the plot files. Therefore additional software, available free on the Internet, may be required to use the plot files (see section "Tar files"). Those without computer capability can obtain plots of the map files through USGS Map-On-Demand service for digital geologic maps (see section "Obtaining plots from USGS Map On Demand Services") or from an outside vendor (see section "Obtaining plots from an outside vendor"). SIM 2956 Digital Contents This report consists of three digital packages. The first is the PostScript Plotfile Package, which consists of PostScript plot files of a geologic map, explanation sheet, and geologic description. The second is the PDF Plotfile Package, and contains the same plotfiles as the first package, but in Portable Document Format (PDF). The third is the Digital Database Package, and contains the geologic map database itself and the supporting data, including base maps, map explanation, geologic description, and references. PostScript plotfile package This package contains the images described here in PostScript format (see below for more information on PostScript plot files): eswnmap.ps A PostScript plotfile containing an image of the geologic map and base maps at a scale of 1:100,000 along with a map key including terrane map, index maps, and correlation chart. eswnsim.ps A PostScript plotfile that contains an image of the pamphlet containing detailed unit descriptions and geological information, a description of the digital files associated with the publication, plus references cited. PDF plotfile package This package contains the images described here in PDF format (see below for more information on PDF plot files): eswnmap.pdf A PDF file containing an image of the geologic map and base maps at a scale of 1:100,000, along with a map key including terrane map, index maps, and correlation chart. eswnsim.pdf A PDF file that contains an image of the pamphlet containing detailed unit descriptions and geological information, a description of the digital files associated with the publication, plus references cited. Digital database package The database package includes geologic map database files for the map area. The digital maps, or coverages, along with their associated INFO directory have been converted to uncompressed ARC/INFO export files. ARC export files promote ease of data handling, and are usable by some Geographic Information Systems in addition to ARC/INFO (see below for a discussion of working with export files). The ARC export files and the associated ARC/INFO coverages and directories, as well as the additional digital material included in the database, are described below: ARC/INFO Resultant Description of Coverage export file Coverage -------------- ----------- -------------------------------- eswn-geol.e00 eswn-geol/ Polygon and line coverage showing faults, depositional contacts, and rock units in the map area. eswn-strc.e00 eswn-strc/ Point and line coverage showing strike and dip information and fold axes. eswn-xsl.e00 eswn-xsl/ Line coverage showing the trend of the cross section (eswn-xsa described below) The database package also includes the following ARC coverages, and files: ARC Coverages, which have been converted to uncompressed ARC/INFO export files: ARC/INFO Resultant Description of Coverage export file Coverage -------------- ----------- -------------------------------- eswn-quad.e00 eswn-quad/ Polygon, line, and annotation coverage showing index map of quadrangles in the map area. eswn-corr.e00 eswn-corr/ Polygon and line coverage of the correlation table for the units in this map database. This database is not geospatial. eswn-so.e00 eswn-so/ Polygon and line coverage showing sources of data index map for this map database. eswn-terr.e00 eswn-terr/ Polygon and line coverage of the index map of tectonostratigraphic terranes in the map area. (Terranes are described eswnsim.txt, eswnsim.pdf, or eswnsim.ps) eswn-xsa.e00 eswn-xsa/ Polygon and line coverage of SW to NE trending cross section. ASCII text files, including explanatory text, ARC/INFO key files, PostScript plot files, and a ARC Macro Language file for conversion of ARC export files into ARC coverages: eswnsim.ps A PostScript plotfile that contains an image of the pamphlet containing detailed unit descriptions and geological information, a description of the digital files associated with the publication, plus references cited. eswnsim.pdf A PDF version of eswnsim.ps eswnsim.txt A text-only file containing an unformatted version of eswnsim.ps without figures. eswnfig1.tif A TIFF file of Figure 1 from eswnsim.ps eswnfig2.tif A TIFF file of Figure 2 from eswnsim.ps eswnso.txt ASCII text-only file containing sources of data related to coverage eswn-so import.aml ASCII text file in ARC Macro Language to convert ARC export files to ARC coverages in ARC/INFO. sim2956d.met A parsable text-only file of publication level FGDC metadata for this report. sim2956e.rev A text-only file describing revisions, if any, to this publication. The following supporting directory is not included in the database package, but is produced in the process of reconverting the export files into ARC coverages: info/ INFO directory containing files supporting the databases. Tar files The three data packages described above are stored in tar (UNIX tape archive) files. A tar utility is required to extract the database from the tar file. This utility is included in most UNIX systems, and can be obtained free of charge over the Internet from Internet Literacy's Common Internet File Formats Webpage (http://www.matisse.net/files/formats.html). Both tar files have been compressed, and may be uncompressed with gzip, which is available free of charge over the Internet via links from the USGS Public Domain Software page (http://edcwww.cr.usgs.gov/doc/edchome/ndcdb/public.html). In addition, several common proprietary freeware programs such as Stuffit Expander (http://www.aladdinsys.com/expander/index.html) and shareware programs such as WinZip (http://www.winzip.com) can handle both tar file extraction and gzip uncompression. When the tar file is uncompressed and the data is extracted from the tar file, a directory is produced that contains the data in the package as described above. The specifics of the tar files are listed below: Name of Size of Directory Data package compressed compressed produced when contained tar file tar file extracted from (uncompressed) tar file ------------ ------------- ------- ---------------------- sim2956a.tgz 17 MB (48 MB) eswnps PostScript Plotfile Package sim2956b.tgz 28 MB (29 MB) eswnpdf PDF Plotfile Package sim2956c.tgz 59 MB (82 MB) eswngeo Digital Database Package PostScript plot files For those interested in the geology of the map area who don't use an ARC/INFO compatible GIS system we have included a digital data package containing two PostScript plot files. One file (eswnmap.ps) contains a color plot of the geologic map at 1:100,000 scale, along with a terrane map, index maps, correlation chart, and map key. A second file (eswnsim.ps) contains the geologic and digital publication description and discussion (this pamphlet). The PostScript image of the geologic map and map explanation is 36 inches wide by 50 inches high, so it requires a large plotter to produce paper copies at the intended scale. In addition, some plotters, such as those with continual paper feed from a roll, are oriented with the long axis in the horizontal direction, so the PostScript image will have to be rotated 90 degrees to fit entirely onto the page. Some plotters and plotter drivers, as well as many graphics software packages, can perform this rotation. The pamphlet is on 8.5 by 11 inch pages. The PostScript plotfiles for maps were produced by the 'postscript' command with compression set to zero in ARC/INFO version 8.1. The PostScript plotfiles for pamphlets were produced in Microsoft Word 10, Adobe Illustrator CS, and Adobe Arcrobat 6.0 on a Macintosh computer using the Destination PostScript File option from the Print command. PDF plot files A second digital package contains PDF versions of the map sheet and pamphlet described above. Adobe Acrobat PDF (Portable Document Format) files are similar to PostScript plot files in that they contain all the information needed to produce a paper copy of a map or pamphlet and they are platform independent. PDFs require less memory to store than PostScript files and are therefore quicker to download from the Internet. In addition, PDF files allow for printing of portions of a map image on a printer smaller than that required to print the entire map without the purchase of expensive additional software. All PDF files in this report have been created from PostScript plot files using Adobe Acrobat Distiller. In test plots we have found that paper maps created with PDF files contain almost all the detail of maps created with PostScript plot files. We would, however, recommend that those users with the capability to print the large PostScript plot files use them in preference to the PDF files. To use PDF files, the user must install a copy of Adobe Acrobat Reader, which is available free from the Adobe website (http://www.adobe.com). Please follow the instructions given at the website to download and install this software. Once installed, the Acrobat Reader software contains an on-line manual and tutorial. There are two ways to use Acrobat Reader in conjunction with the Internet. One is to use the PDF reader plug-in with your Internet browser. This allows for interactive viewing of PDF file images within your browser. This is a very handy way to quickly look at PDF files without downloading them to your hard disk. The second way is to download the PDF file to your local hard disk, and then view the file with Acrobat Reader. We strongly recommend that large map images be handled by downloading to your hard disk, because viewing them within an Internet browser tends to be very slow. To print a smaller portion of a PDF map image using Acrobat Reader, it is necessary to cut out the portion desired using Acrobat Reader and the standard cut and paste tools for your platform, and then to paste the portion of the image into a file generated by another software program that can handle images. Most word processors (such as Microsoft Word) will suffice. The new file can then be printed. Image conversion in the cut and paste process, as well as changes in the scale of the map image, may result in loss of image quality. However, test plots have proven adequate. The full version of Adobe Acrobat (not free) can crop out a section of a PDF map image without loss of resolution. An alternative that maintains the high resolution of the PDF map image is to use a raster image editor (such as Photoshop Elements) that can handle PDF files. This can take a long time and produces a large file (>100 MB), but results in a raster image file that can be cropped as desired. Tests with this method have provided excellent results. Obtaining the Digital Database and Plotfile Packages The U.S. Geological Survey now 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 USGS is: http://www.usgs.gov The Web server for digital publications from the Western Region is: http://geopubs.wr.usgs.gov Go to: http://pubs.usgs.gov/sim/2007/2956 to access this publication. This web page provides access to the digital dabase files, and also affords easy access to the PostScript and PDF plot files for those who do not use digital databases. Obtaining plots from a commercial vendor Those interested in the geologic map, but who use neither a computer nor the Internet, can still obtain the information. Many vendors can download the plotfiles via the Internet. Important information regarding file formats is included in the sections "Tar files," "PostScript plot files," and "PDF plot files" above, so be certain to provide a copy of this document to your vendor. Obtaining plots from USGS Map On Demand Services U.S. Geological Survey provides a plot-on-demand service for maps. In order to obtain plots of this map, contact Map On Demand Services at: U.S. Geological Survey Information Services Box 25286 Federal Center Denver, CO 80225-0046 (303) 202-4200 1-888-ASK-USGS FAX: (303) 202-4695 e-mail: infoservices@usgs.gov Be sure to include with your request the SIM number and the exact names, as listed in the Database Contents section above, of the plotfiles you require. Revisions and version numbers From time to time, new information and mapping, or other improvements, will be integrated into this publication. Rather than releasing an entirely new publication, the USGS has adopted a policy of using version numbers similar to that used in the computer industry. The original version of all publications will be labeled Version 1.0. Subsequent small revisions will be denoted by the increase of the numeral after the decimal, while large changes will be denoted by increasing the numeral before the decimal. Pamphlets and map products will be clearly marked with the appropriate version number. Information about the changes, if any, that have been made since the release of Version 1.0 will be listed in the publication revision file. This file will be available at the publication web site (see above), and will also be included in the digital database package. A simplified version of the revision list will be included in the publication metadata. Digital database format The databases in this report were compiled in ARC/INFO, a commercial Geographic Information System (Environmental Systems Research Institute, Redlands, California), in part with version 3.0 of the menu interface ALACARTE (Fitzgibbon and Wentworth, 1991, Fitzgibbon, 1991, Wentworth and Fitzgibbon, 1991). The files are in either GRID (ARC/INFO raster data) format or COVERAGE (ARC/INFO vector data) format. Coverages are stored in uncompressed ARC export format (ARC/INFO version 7.x). ARC/INFO export files (files with the .e00 extension) can be converted into ARC/INFO coverages in ARC/INFO (see below) and can be read by some other Geographic Information Systems, such as MapInfo via ArcLink and ESRI's ArcView (version 1.0 for Windows 3.1 to 3.11 is available for free from ESRI's web site: http://www.esri.com). The digital compilation was done in version 8.1 of ARC/INFO. Converting ARC export files ARC export 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. From the ARC command line type: Arc: &run import.aml ARC export files can also be read by some other Geographic Information Systems. Please consult your GIS documentation to see if you can use ARC export files and the procedure to import them. Digital compilation The geologic map information was digitized from stable originals of the geologic maps at 1:62,500 scale. The author manuscripts (pen on mylar) were scanned using a Altek monochrome scanner with a resolution of 800 dots per inch. The scanned images were vectorized and transformed from scanner coordinates to projection coordinates with digital tics placed by hand at quadrangle corners. The scanned lines were edited interactively by hand using ALACARTE, color boundaries were tagged as appropriate, and scanning artifacts visible at 1:24,000 were removed. The maps were further edited and new information was added by on-screen digitizing using 1:24,000 scale raster images of standard U.S. Geological Survey topographic maps (DRGs) for reference. Structural data was digitized by on-screen digitizing using scanned and vectorized 1:62,500-scale maps described above or by digitizing from 1:24,000-scale field sheets using a digitizing table or on-screen using 1:24,000-scale DRGs for reference. Base maps Base Map layers were derived from published digital maps (Aitken, 1997) obtained from the U.S. Geological Survey Geologic Division Website for the Western Region (http://wrgis.wr.usgs.gov). Please see the website for more detailed information about the original databases. Because the base map digital files are already available at the website mentioned above, they are not included in the digital database package. Faults and landslides This map is intended to be of general use to engineers and land-use planners. However, its small scale does not provide sufficient detail for site development purposes. In addition, this map does not take the place of fault-rupture hazard zones designated by the California State Geologist (Hart and Bryant, 1999). Similarly, because only some of the landslides in the mapped area are shown, the database cannot be used to completely identify or delineate landslides in the region. For a more complete depiction of landslide distribution, see Nilsen and others (1979), Ellen and others (1997), and Wentworth and others (1997). 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 1:62,500 means that higher resolution information is not present in the dataset. Plotting at scales larger than 1:62,500 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. Database specifics What follows is a brief and simple description of the databases included in this report and the data in them. For a comprehensive look at the database structure and content, please see the FGDC Metadata file, sim2956d.met, included in the database package and available separately at the publication web page. The map databases consist of ARC coverages and supporting INFO files, which are stored in a Universal Transverse Mercator (UTM) projection (Table 1). Digital tics define a 2.5 minute grid of latitude and longitude in the geologic coverages corresponding with quadrangle corners and internal tics. Table 1. Map Projection File The maps are stored in UTM projection. The following is a projection file of the type used in Arc/Info. PROJECTION UTM UNITS METERS ZONE 10 DATUM NAD27 SPHEROID CLARKE1866 PARAMETERS END The content of the geologic database can be described in terms of the lines, points, and areas that compose the map. Each line, point, or area in a map layer or index map database (coverage) is associated with a database entry stored in a feature attribute table. Each database entry contains both a number of items generated by Arc/Info to describe the geometry of the line, point, or area, and one or more items defined by the authors to describe the geologic information associated with that entry. Each item is defined as to the amount and type of information that can be recorded. Descriptions of the database items use the terms explained in Table 2. Table 2. Field Definition Terms ITEM NAME name of the database field (item) WIDTH maximum number of digits or characters stored OUTPUT output width TYPE B-binary integer, F-binary floating point number, I-ASCII integer, C- ASCII character string N. DEC. number of decimal places maintained for floating point numbers Because some of the database structure for is similar for all coverages, some descriptions apply to all coverages in the publication. In that case, the notation has been used to indicate the description is valid for any included coverage. The precise description for a particular coverage can be made by substituting the name of the coverage for . For example, - ID means that the description is the same for every coverage. The specific notation for a single coverage can be derived by replacing with the coverage name (ie. ESWN-GEOL-ID for the coverage eswn-geol). Lines The lines (arcs) are recorded as strings of vectors and are described in the arc attribute table (the format of the arc attribute table is shown in Table 3). They define the boundaries of the map units, the boundaries of open bodies of water, and the map boundaries. These distinctions, including the geologic identities of the unit boundaries, are recorded in the LTYPE field according to the line types listed in Table 4. Table 3. Content of the Arc Attribute Tables ITEM NAME WIDTH OUTPUT TYPE N. DEC FNODE# 4 5 B starting node of arc (from node) TNODE# 4 5 B ending node of arc (to node) LPOLY# 4 5 B polygon to the left of the arc RPOLY# 4 5 B polygon to the right of the arc LENGTH 4 12 F 3 length of arc in meters # 4 5 B unique internal control number -ID 4 5 B unique identification number LTYPE 35 35 C line type (see Table 4) FAULTNAME 35 35 C records the name of some faults (eswn-geol.aat only) Table 4. Line Types Recorded in the LTYPE Field eswn-geol and eswn-terr -------------------------------- contact, approx. located contact, certain contact, concealed contact, inferred fault, active fault, active_p fault, approx. located fault, certain fault, concealed fault, concealed, queried fault, inferred fault, inferred, queried map boundary reverse fault, certain scratch boundary thrust fault, approx. located thrust fault, certain thrust fault, concealed thrust fault, concealed, queried thrust fault, inferred thrust fault, inferred, queried water boundary eswn-strc -------------------------------- anticline, approx. located anticline, certain anticline, concealed syncline, approx. located syncline, concealed eswn-so and eswn-quad -------------------------------- contact, certain map boundary quad boundary source boundary eswn-corr ------------------ age, bracket box bracket leader outline protolith Note, not every line type listed is present in every coverage. For example, eswn- terr only has some of the fault types listed. The geologic linetypes are ALACARTE line types that correlate with the geologic line symbols in the ALACARTE line set GEOL.LIN according to the ALACARTE lines lookup table (GEOL.LUT). For more information on ALACARTE and its linesets, see Wentworth and Fitzgibbon (1991). Areas Map units (polygons) are described in the polygon attribute table (the format of the polygon attribute table is shown in Table 5). In the geologic coverage (eswn-geol) and the correlation coverage (eswn-corr), the identities of the map units are recorded in the PTYPE field by map label (Table 6). Map units are described more fully in the accompanying text file. In other coverages, various areal information is recorded in the PTYPE field (data source region number, assemblage number, terrane label, quadrangle name). Note that ARC/INFO coverages cannot contain both point and polygon information, so only coverages with polygon information will have a polygon attribute table, and these coverages will not have a point attribute table. Table 5. Content of the Polygon Attribute Tables ITEM NAME WIDTH OUTPUT TYPE N. DEC AREA 4 12 F 3 area of polygon in square meters PERIMETER 4 12 F 3 length of perimeter in meters # 4 5 B unique internal control number -ID 4 5 B unique identification number PTYPE 35 35 C unit label Table 6. Unit labels (see the "Geologic explanation and acknowledgements" section for a description of map units) Jgb Jgvm Jgvm? Jk Jmi Jsp Jv KJfc KJfgc KJfgs KJfgs? KJfs KJgv KJgvl KJsp Kfm Kfm? Kfmc Kfmg Kfss Kgvu Kv QTc QTc? QTge QThg QTob QTt Qa Qf Qha Qhay Qhb Qhbm Qhc Qhf Qhff Qhl Qht Qhty Qls Qlsa Qlso Qlsr Qoa Qoa? Qpa Qpf Qpt Qr Qt Tbm Tbm? Tc Tci Td Tdr Tkt Tms Tn Tp Tp? Tr Ts Tsa Tsag Tsai Tsb Tsft Tslt Tsr Tsrb Tsri Tsrp Tsrs Tss Tssd Tst Tstx Tsv Tswt Twg af afbm alf ch fgc fs fsr gs gs? m sc sp sp? spm water Note, not every unit label listed is present in every coverage. For example, queried units are not present in the correlation table coverage. Points Data gathered at a single locality (points) are described in the point attribute table (the format of the point attribute table is shown in Table 7). The identities of the points from compilation sources are recorded in the PTTYPE field by map label (Table 8 and 9). Note that ARC/INFO coverages cannot contain both point and polygon information, so only coverages with point information will have a point attribute table, and these coverages will not have a polygon attribute table. Table 7. Content of the Point Attribute Tables ITEM NAME WIDTH OUTPUT TYPE N. DEC AREA 4 12 F 3 area of polygon in square meters PERIMETER 4 12 F 3 length of perimeter in meters # 4 5 B unique internal control number -ID 4 5 B unique identification number PTTYPE 35 35 C unit label DIP 3 3 I dip of bedding or foliation (structure coverage only) STRIKE 3 3 I strike of bedding or foliation (structure coverage only) Table 8. Point Types Recorded in the PTTYPE Field for structure coverage (eswn- strc) eswn-struc ----------------------------- air photo attitude approx bedding bedding bedding w/tops crumpled bedding flat bedding foliation foliation and bedding joint joint unmineralized ot bedding ot bedding w/tops vert bedding vert foliation and bedding The geologic point types in the structure coverage are mostly ALACARTE point types that correlate with the geologic point symbols in the ALACARTE point set ALCGEOL.MRK according to the ALACARTE point lookup table. For more information on ALACARTE and its pointsets, see Wentworth and Fitzgibbon (1991).