readme.txt file for the Digital Geologic Map and Database of the Frederick 30' X 60' Quadrangle, Maryland, Virginia, and West Virginia Version 1.0 - U.S. Geological Survey Open File Report, OFR-02-437 GENERAL DESCRIPTION: The digital geologic map and database of the Frederick 30' X 60' quadrangle is a combination of Geographic Information System (GIS) layers and a Microsoft (MS) Access database. The geologic map and database are intended for application to land use decisions, soil mapping, groundwater availability and quality, aggregate resources, and engineering and environmental studies. The geologic GIS Layers are: bedrock, surficial, cross sections, dikes, faults, structural measurements, and sinkhole locations. The base GIS themes are: hydrology, land cover, political boundaries, roads, and elevation contours. Consult the metadata files included with this report for detailed descriptions for the GIS data layers and their attributes. The GIS data are provided in Environmental Systems Research Institute's (ESRI) Arc/INFO coverage, grid, and interchange (export) file formats.* Additionally, the GIS data are provided in the Spatial Data Transfer Standard (SDTS) data exchange format. The GIS data can be viewed using the ArcExplorer software included in the SOFTWARE folder on this CD-ROM. ArcExplorer is a geographic data viewer developed by ESRI. Consult the readme.txt and arcexplorer.pdf files in the SOFTWARE folder for ArcExplorer installation instructions. Once installed, use ArcExplorer to open the project file named OF02437.AEP. The Portable Document Format (PDF) files included on this CD-ROM can be viewed using Adobe Acrobat Reader software. If you wish to download the latest version of Acrobat Reader free of charge, go to http://www.adobe.com/products/acrobat. CD DIRECTORY LAYOUT: |--README.TXT__(This file) | | |--homepage.htm__Index page for website contents in HTML format | | |--index.htm__Photo tour in HTML format | | |--OF02437P1.PDF__(PostScript and Portable Document Format versions of the geologic units map (Sheet 1 of 2, 57" long x 36" wide) | | |--OF02437P2.PDF__(PostScript and Portable Document Format versions of the land cover and cross section map (Sheet 2 of 2, 42" long x 36" wide) | | |--DMUPAMPHLET.PDF__Description of map units pamphlet in Adobe Portable Document Format | | |--OF02437.PDF___Text pamphlet in Adobe Portable Document Format | | |--METADATA-----(Contains metadata files for the report) | | | |--ACCESS--(Contains Microsoft Access database and its dBASE and ASCII text file equivalents) | | | | | |--COVERS--(Contains Arc/Info coverages for the geologic and base map themes) | | | | | |of02437_gz.tar__(GZip Tar Unix Compressed data files in unprojected geographic coordinates, units in decimal degrees)--|--EXPORT--(Contains Arc/Info export-interchange files for the geologic and base map themes) |--DATA--| | | |of02437.zip__(PC Zip Compressed data files in unprojected geographic coordinates, units in decimal degrees)------------| | |--GRID--(Contains Arc/Info grid of land cover) | | | | | |--SDTS--(Contains Spatial Data Transfer Standard (SDTS) data exchange files for the geologic and base map themes) | | | |--of02437p1.ps.gz__(GZip Unix compressed file for printing the paper geologic units map (Sheet 1 of 2, 57" long x 36" wide) in PostScript format) |--GRAPHICS----|--of02437p1.zip__(PC Zip compressed file for printing the paper geologic units map (Sheet 1 of 2, 57" long x 36" wide) in PostScript format) | |--of02437p2.ps.gz__(GZip Unix compressed file for printing the paper land cover and cross section map (Sheet 2 of 2, 42" long x 36" wide) in PostScript format) | |--of02437p2.zip__(PC Zip compressed file for printing the paper land cover and cross section map (Sheet 2 of 2, 42" long x 36" wide) | | | |--PDF_PAMPHLET--(Contains support files for OF02437.PDF) |--IMAGE_FILES-| | |--PHOTOGALLERY--(Contains support files for PHOTOGALLERY.HTM) PROJECTION INFORMATION: Projection and Coordinate System used: Geographic (latitude/longitude) Datum used: North American Datum of 1983 (NAD83) Ellipsoid used: GRS80 Map Units: Decimal degrees Scale of Compilation of Geologic Data: 1:100000 Scale of field mapping: 1:24000 to 1:100000 Basemaps: U.S. Geological Survey (USGS) 1:100000-scale Digital Line Graph layers for hydrography, hypsography, political boundaries, and roads. Land cover from USGS National Land Cover Data set. * Use of product names does not imply endorsement by the U.S. Government