DESCRIPTION OF THE DIGITAL DATABASE FOR 

  Geologic Map of the East Half of the Bellevue South 7.5'x 
  15' Quadrangle, Issaquah Area, King County, Washington

  by, Derek B. Booth, Timothy J. Walsh, Kathy G. Troost, and 
  Scott A. Shimel

  USGS SCIENTIFIC INVESTIGATIONS MAP 3211


  INTRODUCTION

  This digital database for the Geologic Map of the East Half 
  of the Bellevue South 7.5'x 15' Quadrangle, Issaquah Area, 
  King County, Washington (USGS SIM-3211) includes several 
  ArcInfo coverages (individual vector datasets) along with 
  supporting files and metadata.  The coverages have been 
  converted to ArcInfo export files. Relative to coverages, 
  ArcInfo export files are easier to transport from one 
  ArcInfo installation to another and are usable by some 
  other Geographic Information Systems. 

  All GIS data are in TRANSVERSE MERCATOR projection, 
  NAD_1927_UTM_Zone_10N
  Parameters:
    False_Easting: 500000.000000
    False_Northing: 0.000000
    Central_Meridian: -123.000000
    Scale_Factor: 0.999600
    Latitude_Of_Origin: 0.000000
  Linear Unit: Meter (1.000000)
  Geographic Coordinate System: 
    Name: GCS_North_American_1927
  Datum: D_North_American_1927
     Spheroid: Clarke_1866

  Together with the geologic map, the database provides 
  georeferenced 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 spatial resolution (scale) of the 
  database is 1:24,000 or less. The content and character of 
  the database, as well as how to obtain the database, are 
  described below. 


  CONTENT

  This database contains 7 ArcInfo coverages with geologic 
  content: 

  ISSAGEOL     Network coverage of geology with arcs, 
               polygons, and polygon label points.

  ISSALS       Network coverage of landslide overlay with 
               arcs, polygons and polygon label points 

  ISSASTRUCT   Point coverage of bedding plane strikes and 
               dips with orientation data.
   
  ISSASAMPOINT Point coverage of samples dated by carbon-14 
               method

  ISSAEXPLOR   Point coverage of wells, borings, test pits 
               and other data.  

  ISSASTAT     Point coverage of station localities

  ISSALINES    Arc coverage with location of structural 
               contours, fold axes, and cross-section 
               location  

  DIGITAL DATABASE AND METADATA PACKAGE 
  (sim3211_database.zip)

  The ARC export files and associated ArcInfo coverages, as 
  well as the additional digital material included in the 
  database package, are described below:

  File                   Description 
  -----------------------------------------------------------

  sim3211_readme.txt     This readme file

  ISSArelief.tif         Uncompressed TIFF-format shaded 
                         relief image with geologic map unit 
                         colors

  ISSArelief.tfw         World file that locates 
                         ISSArelief.tif in UTM projection, 
                         units feet, datum NAD27

  sim3211_metadata.txt   Text-format FGDC-style metadata for 
                         the database package as a whole

  Each coverage contains detailed XML-format FGDC-style 
  metadata specific to the coverage. This metadata is stored 
  as file metadata.xml within the coverage directory, and is 
  easily browsed from within ArcCatalog, or read with a web 
  browsers (e.g., Firefox, Safari, Internet Explorer) 


  Geology subdirectory (coverages)
  --------------------------------

  issageol.e00       ArcInfo export file of geologic 
                     contacts, faults, and generalized map 
                     units.

  issals.e00         ArcInfo export file of landslide overlay 

  issastruct.e00     ArcInfo export file of bedding strike 
                     and dip.

  issalines.e00      Arcinfo export file of fold axis, 
                     structural contours, and cross section 
                     line locations.

  issasampoint.e00   Arc info export file of carbon14 sample 
                     location points.

  issastat.e00       ArcInfo export file of field station 
                     locations.

  issaexplor.e00     ArcInfo export file of geotechnical test 
                     locations.

  Users of the database package may wish to download the 
  geologic map pdf for the contained Description of Map 
  Units. 

  The material described above is available on the World-Wide 
  Web at http://pubs.usgs.gov/sim/3211/. 


  ZIP FILES

  The files described above are packaged within a ZIP file. 
  Utilities to uncompress ZIP files are available for most 
  all operating systems and may be found readily with a 
  simple web search. 


  DIGITAL DATABASE FORMAT

  The databases in this report were compiled in ArcInfo, a 
  commercial Geographic Information System (Environmental 
  Systems Research Institute,Redlands, California.  
  ArcInfo coverages were converted to uncompressed ARC export 
  files (.e00 extention, ArcInfo version 9.3 for Windows XP). 
  These export files can be converted into back into 
  coverages in ArcInfo with the IMPORT command, e.g., 

       Arc: import cover xxx.e00 xxx 

  where xxx is the coverage name. The files can also be read 
  by some other 
  Geographic Information Systems. While specifications for 
  the .e00 format has not been published by Environmental 
  Systems Research Institute, the files are plain ASCII, the 
  structure is relatively easy to decode and 3rd-party 
  descriptions are available via Web search for ".e00 
  format".


  OBTAINING THE DIGITAL DATABASE

  Go to 

  http://pubs.usgs.gov/sim/3211/


  to access the database package and the remainder of this 
  publication.

  ACKNOWLEDGMENTS

  We thank Zenon Valin for review of this readme, the 
  database package, and associated metadata.