>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

http://pubs.usgs.gov/of/2002/of02-437/of02437.pdf