Digital geologic map and database of the Frederick 30 X 60 minute quadrangle, Maryland, Virginia, and West Virginia

The following is a brief description of the data layers, tables, and their associated attributes that are used in this report.

GEOLOGIC DATA:
ASECTION - Line and polygon data for the A-A' cross section
  ASECTION.AAT items:
    PLOTCODE - Used for plotting
    TYPE - Used to identify faults
  ASECTION.PAT items:
    PLOTCODE - Used for plotting
    MAPUNIT - Geologic map unit code

BEDROCK - Polygon data layer of bedrock geologic map units
  BEDROCK.PAT items:
    MAPUNIT - Bedrock geologic map unit code

BSECTION - Line and polygon data for the B-B' cross section
  BSECTION.AAT items:
    PLOTCODE - Used for plotting
    TYPE - Used to identify faults
  BSECTION.PAT items:
    PLOTCODE - Used for plotting
    MAPUNIT - Geologic map unit code
    META - Used to identify thermally metamorphosed rocks.  Set to 'JTrtm'.

FAULT - Line data layer of geologic faults
  FAULT.AAT items:
    TYPE - Type of fault
      TYPE Code  Description
           N	 Normal
           T     Thrust
          NT     Normal reactivated as thrust
          OT     Overturned thrust
          SS     Strike-slip
         ARO     Arrow showing movement along strike-slip fault
           U     Unclassified
    CODE - Identifies fault segments which are overlaid by surficial deposits
           (CODE = 2).  Used for plotting.

LAKEBED - Line data layer of lakebed locations
  LAKEBED.AAT items:
    TYPE - Set to 'Lakebed'

LINES - Line data layer of geologic cross sections
  LINES.AAT items:
    XLINE - Identifies cross section, set to "A-A'" or "B-B'"

META - Polygon data layer of thermally metamorphosed rocks
  META.PAT items:
    MAPUNIT - Geologic map unit code.  Set to 'JTrtm'.

NEAT - Unattributed line data layer of map neatline

SINK - Point data layer of sinkhole locations
  SINK.PAT items:
    MAPUNIT - Set to 'Sinkhole'

STRUCTURE - Point data layer of geologic structure
  STRUCTURE.PAT items:
    DIP - Dip value (planar data) or plunge value (linear data)
    AZIMUTH - Angle measured from North in right-hand rule (planar data).
    TYPE - Type of geologic structure
      TYPE Code  Description
        AGE      Sample site for U-Pb isotopic technique for age date
         HB      Horizontal bed
        I1C      Inclined first-generation Paleozoic cleavage and (or) schistosity
        I2C      Inclined second-generation Paleozoic cleavage and (or) schistosity
         IB      Inclined bed
         IF      Inclined Middle Proterozoic foliation
         MA      Minor antiform
        MPF      Inclined mylonitic and phyllonitic foliations
         OB      Overturned bed
         QM      Quarry or mine
        RAD      Greater than 200 pCi/L of soil gas radon
        V1C      Vertical first-generation Paleozoic cleavage and (or) schistosity
        V2C      Vertical second-generation Paleozoic cleavage and (or) schistosity
         VB      Vertical bed
         VF      Vertical Middle Proterozoic foliation
    SUB_TYPE - Type of quarry mine
      SUB_TYPE
        Code    Description
         Au     Gold
          C     Chromite
         Cu     Copper
          D     Diabase
          F     Hematite, limonite, and iron-ore
          L     Limestone
          M     Marble
          S     Building stone
         Zn     Zinc
    SYMBOL_ANG - Standard Cartesian angle measured from East.  Used for plotting.
    DIPDIR - Direction of dip (planar data) or trend (linear data) measured from North
    SYMBOL - Symbol number, used for plotting

SURFICIAL - Polygon data layer of surficial geologic map units
  SURFICIAL.PAT items:
    MAPUNIT - Surficial geologic map unit code

ZMD_DIKE - Line and polygon data layer of Zmd dikes
  ZMD_DIKE.AAT items:
    TYPE - Set to 'Zmd'
  ZMD_DIKE.PAT items:
    MAPUNIT - Set to 'Zmd'

02437 - Geologic database
  If you are using Arc/Info Workstation you can access the data in this table using either the
  JOINITEM, RELATE, or CURSOR functions and the INFO item MAPUNIT.  Use the RELATE function to
  access this data from ArcMap.  If you are using ArcView, add the table 02437.DBF to the
  project and use either the JOIN or LINK functions and the item MAPUNIT to access the data.
  Alternatively, the database 02437.MDB can be viewed using Microsoft Access.
    02437 items:
      MAPUNIT - Geologic map unit code
      SURF_BED
      SURFTYPE
      LITHPRI
      LITHSEC
      LITHTER
      FORM
      MEMBER
      GROUP
      SUPERGROUP
      ROCKCLASS
      AGE
      GEOCHR
      GEOCHRTECH
      GEOCHRREF
      FOSSIL
      FOSSILTYPE
      FOSSILREF
      CORRELEXTR
      ORIGIN
      RES
      RESREF
      COLOR
      MINPRI
      MINSEC
      MINOTH
      CLASTPRI
      CLASTSEC
      CEMENT
      THICKAPPRX
      THICKRANGE
      BEDTHIN
      BEDMEDIUM
      BEDTHICK
      CONTUP
      CONTLOW
      FOLPRI
      FOLSEC
      FOLTER
      CMPM
      RMPM
      RMRM
      DEFORMAGE
      DEFORMTECH
      DEFORMREF
      COMMENTS

BASE DATA:
HYDRO - Line and polygon data layer of hydrographic features
  HYDRO.AAT items:
    ENTITY_LABEL - DLG code
    ENTITY_DEF - Short definition of the DLG code contained in ENTITY_LABEL
    BANK - Defines the right (R) and left (L) limits of a double-line feature when facing downstream
    INTERMITTENT - Defines any hydrographic feature which flows intermittently
    COINCIDENT - Identifies lines shared by two or more hydrographic features
  HYDRO.PAT items:
    ENTITY_LABEL - DLG code
    ENTITY_DEF - Short definition of the DLG code contained in ENTITY_LABEL
    ELEVATION - Water surface elevation, whole meters

NLCD - Raster land cover data set
  NLCD.VAT items:
    VALUE - Land cover code
      VALUE Code  Description
         11      Open water
         21      Low intensity residential
         22      High intensity residential
         23      Commercial/Industrial/Transportation
         32      Quarries/Strip mines/Gravel pits
         33      Transitional
         41      Deciduous forest
         42      Evergreen forest
         43      Mixed forest
         81      Pasture/Hay
         82      Row crops
         85      Urban/Recreational grasses
         91      Woody wetlands
         92      Emergent herbaceous wetlands
    COUNT - Total number of cells belonging to each value code
    SYMBOL - Symbol number, used for plotting

POLBND - Line and polygon data layer of state and county boundaries:
  POLBND.AAT items:
    POLBND-ID
      TYPE - State or county boundary
  POLBND.PAT items:
    STATE_NAME - State in which county resides
    CNTY_NAME - County name
    STATE_FIPS - State FIPS code (character field)
    CNTY_FIPS - County FIPS code (character field)
    FIPS - FIPS code for state/county (character field)
    MAJOR# - DLG code
    MINOR# - DLG code
      Major DLG  Minor DLG
        Code       Code     Description
         91        ---      State FIPS code (integer field)
         92        ---      County FIPS code (integer field)

ROADS - Line data layer of major highways
  ROADS.AAT items:
    MAJOR# - DLG code
    MINOR# - DLG code
      Major DLG  Minor DLG
        Code       Code     Description
        170        201      Primary route, class 1, undivided
        170        203      Primary route, class 1, divided
        170        205      Secondary route, class 2, undivided
        170        207      Secondary route, class 2, divided
        170        209      Road or street, class 3
        170        402      Cloverleaf or interchange
        172        ---      Interstate route number
        173        ---      U.S. route number
        174        ---      State route number

TOPO - Line data layer of elevation contours
  TOPO.AAT items:
    MAJOR# - DLG code
    MINOR# - DLG code
      Major DLG  Minor DLG
        Code       Code     Description
         20        20O      Contour (index or intermediate)
         20        201      Carrying contour
         20        204      Amended contour
         20        208      Closure line
         20        611      Depression
         24        ---      Elevation in whole meters
    TYPE - Type of contour: index (Index) or intermediate (Inter),
           used for plotting