Bedrock geologic map of the Hubbard Brook Experimental Forest, Grafton County, New Hampshire

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What does this data set describe?

Bedrock geologic map of the Hubbard Brook Experimental Forest, Grafton County, New Hampshire
The bedrock geology of the Hubbard Brook Experimental Forest, Grafton County, New Hampshire is described in this report of new field investigation. The database includes contacts of bedrock geologic units, faults, folds, and other structural geologic information, as well as the base maps on which the mapped geological features are registered. This report supersedes Barton (1997).
Data were originally collected in UTM coordinates, zone 19, NAD 1927, and reprojected to geographic coordinates (Lat/Long), NAD 1983. The database is accompanied by two large format color maps, a readme.txt file, and a explanatory pamphlet.
  1. How might this data set be cited?
    Burton, William C., Walsh, Gregory J., and Armstrong, Thomas R., 2000, Bedrock geologic map of the Hubbard Brook Experimental Forest, Grafton County, New Hampshire: U.S. Geological Survey Open-File Report 00-45, U.S. Geological Survey, Reston, Virginia.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -71.875
    East_Bounding_Coordinate: -71.625
    North_Bounding_Coordinate: 44.000
    South_Bounding_Coordinate: 43.875
  3. What does it look like? (GIF)
    Reduced-size image showing the general layout of map sheet 1. 864x485 pixels, 24-bit color. (GIF)
    Reduced-size image showing the general layout of map sheet 2. 864x537 pixels, 24-bit color.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1998
    Ending_Date: 2000
    publication date
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: map
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Entity point
      • Complete chain
      • GT-polygon composed of chains
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitude and longitude values are specified in decimal degrees. The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257.
  7. How does the data set describe geographic features?
    The geologic unit polygons in the CONTX coverage
    was filled with colors from the colornames.shd shadeset in
    Arc/Info.  A lookup table was created in Arc/Info to fill the
    polygons.  The lookup table contains the items CODE and SYMBOL.
    Here is the content of the lookup table:
    Record  CODE       SYMBOL
         1  Dg         110
         2  Dkg        113
         3  Dp         119
         4  Sp          19
         5  Spp         60
         6  Srb         95
         7  Srcs        47
         8  Srfg        93
         9  Srg         96
        10  Srgt       101
        11  Srlg        49
        12  Srq         84
        13  Srr         79
        14  Srrt        81
        15  Srs         85
    The following is a brief description of the ARC/INFO coverages.
    CONTX coverage:
     Item CODE in CONTX.PAT contains the map unit designators.
         (Srb, Dkg, etc.)
     Item LBLTXT in CONTX.PAT is used for selective plotting of code
          labels; valid entry is 'n' or item is left blank.
     Item TYPE is a general category of rock type:
          m=metamorphic and p=plutonic
     Item LINTYPE in CONTX.AAT is used for plotting different line types.
          Valid entries are "concealed" where contacts are under water,
          or item is left blank.
          Concealed plotted as dotted line.
          Blank plotted as solid line.
     Look-up table CONTX.LUT contains the following items:
         CODE = map unit designator
         AGE_SORT = a relative number used to sort the units by age
         FORMATION = the formation name
         AGE = geologic age of the map unit
         MAP_UNIT = simplified description of rock type(s)
                    (Complete description is in the accompanying text)
     Lithology attribute table CONTX.LITH contains the following items:
         CODE = map unit designator
         SURF_BED = surficial or bedrock unit
         LITHPRI = primary lithology in the map unit
         LITHSEC = secondary lithology in the map unit
         FORM = formation name
         ROCKCLASS = rock type
         AGE = geologic age of the map unit
         MINPRI = most characteristic minerals
         MINSEC = additional common minerals
         MINOTH = accessory minerals
         FOLPRI = dominant generation of foliation in the rock
         FOLSEC = subordinate generation of foliation in the rock
         RMPM = regional prograde-metamorphic minerals
         RMRM = regional retrograde-metamorphic minerals
         DEFORMAGE = age of deformation
     After importing the CONTX.E00 file you will find the look-up table
     and the lithology attribute table in the INFO directory.  If you are
     using ArcView you can add the tables to the project by navigating to
     the INFO directory, specifying the INFO file type, and selecting the
     desired table.  If you are using Arc/Info you can access the data in
     the two tables using either the JOINITEM or RELATE operations and the
     INFO item CODE.
    Structural geology point coverages POINT and STRUX:
    Coverage POINT contains all of the structural data points and the
    points in the database are located within the polygons in the outcrop
    coverage -- the point locations are the original mapped locations.
    Coverages STRUX contains structural data used for cartography on
    Plate 1.  The locations of the points in STRUX have been moved from
    the original locations in POINT for plotting purposes only.
    Any spatial analysis should use the POINT coverage data.
    The STRUX coverage contains annotation for dip and plunge values.
    The annotation is not present in the POINT coverage.
    The PAT files for the point coverages contain the following
    user-defined items:
    STATION     number of field station
    POSFMT      position format from PLGR+96 GPS unit
    ZONE        UTM zone from PLGR+96 GPS unit
    HDATUM      horizontal datum from PLGR+96 GPS unit
    HRZERR      horizontal error from PLGR+96 GPS unit
    ELEV        elevation from PLGR+96 GPS unit
    VDATUM      vertical datum from PLGR+96 GPS unit
    ELEVUNIT    elevation unit from PLGR+96 GPS unit
    Note on HRZERR --
    	The database includes the horizontal accuracy of point
    	features as measured and recorded by the PLGR+96 GPS unit.
    	The stated accuracy of the PLGR+96 is +/- 16 meters.
    Note on POSFMT through ELEVUNIT --
    	These fields are recorded by the PLGR+96 GPS unit.  In the
    	PAT files, some points do not have entries in these fields.
    	These points have been located without the use of GPS.
    The following items are described in more detail below:
    STRIKE      units in degrees
    DIP         units in degrees
    DIPDIR      units in degrees
    SYMBOL_ANG  units in degrees
    SPACING     units in meters
    WIDTH       units in meters
    APERTURE    units in meters
    CODE        relate item for dikes, same as code in CONTX.PAT and LUT
    NO_MSMT     number of multiple measurements for some brittle features
    Here is the detailed  explanation of some of the items:
     DIP = dip value (planar data) or plunge value (linear data)
     STRIKE = measured from north in right-hand rule (planar data)
     DIPDIR = Direction of dip (planar data) or trend (linear data)
              measured from north
    For STRIKE and DIPDIR:
            North = 0                              |
            East = 90                     270 -----|----- 90
            South = 180                            |
            West = 270                            180
    SYMBOL_ANG  = refers to a standard cartesian angle measured
       from EAST:
            North = 90                            |
            East = 0                     180 -----|----- 0
            South = 270                           |
            West = 180                           270
       SYMBOL_ANG is used for symbol rotation.
       In ARC/INFO calculate pseudo item $angle = symbol_ang
       Planar symbols with symbol_ang = 0 look like this:
       Linear symbols with symbol_ang = 0 look like this:
    SYMBOL refers to a pattern number in GEOLOGY.MRK.
    ROTATION refers to the rotation sense of minor folds as viewed
    down plunge or offset on minor faults.  Valid entries are:
         clockwise (right-lateral) = cw
         counterclockwise (left-lateral) = cc
    REL_AGE refers to the relative age of fabrics.
    Valid entries are: n-1, n, n+1, n+2, etc.
    TYPE refers to the general type of geologic structure.
    Valid entries are: planar, linear, or other
    SUB_TYPE refers to the specific geologic structure.
    Valid entries used in this report arranged by TYPE:
         1      1     4     linear     elongation
         2      2    76     linear     fold axis
         3      3    14     linear     glacial grooves
         4      4     6     linear     intersection lineation
         5      5     5     linear     mineral lineation
         6      6     1     linear     refolded fold axis
         7      7    13     linear     slickensides
         8      8     1     other      spring
         9      9    79     planar     axial surface
        10     10    28     planar     bedding
        11     11    22     planar     cleavage
        12     12    11     planar     deformed schistosity
        13     13    76     planar     dike
        14     14     2     planar     fault
        15     15    22     planar     foliation
        16     16     4     planar     graded bedding
        17     17    17     planar     igneous flow foliation
        18     18  1579     planar     joint
        19     19    17     planar     joint set
        20     20    24     planar     joint zone
        21     21    76     planar     layer parallel schistosity
        22     22     3     planar     mylonite
        23     23    13     planar     normal fault
        24     24     4     planar     overturned bedding
        25     25     1     planar     refolded axial surface
        26     26     1     planar     reverse fault
        27     27   599     planar     schistosity
        28     28    24     planar     vein
    The following are also used in the POINT coverage:
    SPACING	spacing of joints in joint sets in meters
    WIDTH		width of joint zone or thickness of dike in meters
    APERTURE	aperture of joint openings in meters
    The following are used in the POINT coverage to describe minerals
    on joint surfaces and in veins:
    MIN1		primary mineral
    MIN2		secondary mineral
    MIN3		tertiary mineral
    The following values are used in the report, some were modified
    after Kretz (1983):
    ank   ankerite
    dol   dolomite
    hem   hematite
    lm    limonite
    ms    muscovite
    pyl   pyrolusite
    qtz   quartz
    sil   sillimanite
    sul   sulfides
    tur   tourmaline
    Kretz, R., 1983, Symbols for rock-forming minerals: American
    Mineralogist, v. 68, nos. 1-2, p. 277-279.
    TOPOFEAT	topographic feature parallel to geologic structure
    Values used in this report include:
    joint face
    Line coverage FAULT contains the following item:
      TYPE = type of fault (normal, reverse, thrust, etc.)
    Line coverage LINES contains the following item:
      TYPE = type of geologic line (axial traces, folds, isograds, cross-section lines, etc.)
    Polygon coverage NEAT represents the neat line boundary of the Hubbard Brook Experimental Forest project area
    Polygon coverage OUTCX represents the location of bedrock outcrops within the Hubbard Brook Experimental Forest project area
    Polygon coverage BOUNDS represents the political boundary of the Hubbard Brook Experimental Forest
    Line and polygon coverage HYDRO represents the surface water hydrography within the Hubbard Brook Experimental Forest
    Line coverage ROADS contains the following items:
      GRANITID = GRANIT-assigned feature number
      CLASS = GRANIT-assigned feature number
    Line coverage TOPO contains the following items:
      ELEV = elevation in feet above mean sea level
      CI = contour interval (in feet) used for plotting
      SYMBOL = line symbol used for plotting
    Point coverage WELLS contains the following items:
      ROCKTYPE = Lower Rangeley (lr), Upper Rangeley (ur), and Concord Granite (cg)
      SYMB = symbol value used for rplotting
      PTYPE = point type (well)

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • William C. Burton
    • Gregory J. Walsh
    • Thomas R. Armstrong
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Gregory J Walsh
    U.S. Geological Survey
    P.O. Box 628
    Montpelier, VT

    802-828-4514 (voice)

Why was the data set created?

Our mapping study was funded by the USGS Toxic Substances Hydrology Program and was undertaken for the following reasons: 1) to ascertain whether the area might have a greater number of mappable lithologic units than shown on Barton's (1997) map, and to verify the stratigraphically higher formations shown on the map; 2) to have sufficient data to draw geologic cross- sections through the Mirror Lake research site; 3) to gather more data on brittle fracture distribution and orientation; and 4) to assess the degree to which the subsurface lithologies, ductile structures, and fractures observed at the two Mirror Lake well fields correlate with the geology of the surrounding region.

How was the data set created?

  1. From what previous works were the data drawn?
    Barton (1997) (source 1 of 1)
    Barton, C.C., 1997, Bedrock geologic map of Hubbard Brook Experimental Forest and maps of fractures and geology in roadcuts along Interstate 93, Grafton County, New Hampshire: U.S. Geological Survey Miscellaneous Investigations Series Map I-2562, U.S. Geological Survey, Reston, Virginia.

    Type_of_Source_Media: mylar
    Source_Scale_Denominator: 12000
    Provided base map data.
    Used to produce polygon coverage of political boundary of the Hubbard Brook Experimental Forest,
    For line coverage of surface water hydrography (hydro.e00) Some stream locations have been changed slightly from Barton (1997) as the result of remapping using GPS with the Federal precise positioning service.
    For line coverage of roads (roads.e00), data were modified from Barton (1997) and road coverages for the Mt. Kineo and Woodstock 7.5-minute quadrangles obtained from the New Hampshire GRANIT system.
    For line coverage for hypsography (topo.e00) data were modified from Barton (1997). Modifications include corrections to elevation attributes and combined with original unpublished data from U.S. Forest Service map, 1956. Digitized by Cornell Laboratory for Environmental Applications of Remote Sensing (CLEARS), Center for the Environment, Cornell University, Ithaca, New York.
    For point coverage of groundwater wells (wells.e00), some wells have been added to the dataset from Barton (1997). The well locations were obtained by GPS.
  2. How were the data generated, processed, and modified?
    Date: 1998 (process 1 of 1)
    Geology mapped by Burton, Walsh, and Armstrong in the summer and fall of 1998 and the summer of 1999 at a scale of 1:10,000. Locational information was provided by Rockwell PLGR+96 GPS receivers using the Federal precise positioning service. The line and polygon data were compiled on a mylar and scanned at 400 dpi on an Anatech Eagle 4080T scanner. The raster files (TIF) were converted to vector files (DXF)using GTX OSR version 2.0 raster-to-vector conversion software. The vector files were imported to Arc/Info version 7.2.1. Point data were collected with GPS and hand-held 3COM Palm Pilot III PDA computers. Data from the PDAs were combined in Microsoft Access, and then imported as ASCII text files and DBASE IV (dbf) files into Arc/Info.
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the observations, including topology?
    Polygon and chain-node topology present.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: none
Although all data released in this report have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and (or) the functioning of the software. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    Greg Walsh
    87 State Street, Room 324
    Montpelier, Vermont

    (802) 828-4528 (voice)
    (802) 828-4465 (FAX)
    Hours_of_Service: Monday - Friday 9:00 - 5:00 EST
  2. What's the catalog number I need to order this data set? USGS Open-File Report 00-45
  3. What legal disclaimers am I supposed to read?
    These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product or process disclosed in this report, and represents that its use would not infringe privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data or related materials. Reference therein to any specific commercial product, process, or related service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: Geologic contacts and structural features, base map data, along with symbols and markers for use in Arc/Info in format ARCE (version 7.2.1) Size: 5.2
      Network links:
    • Cost to order the data: none

Who wrote the metadata?

Last modified: 13-Jun-2016
Last Reviewed: 30-Mar-2001
Metadata author:
U.S. Geological Survey
Greg Walsh
87 State Street, Room 324
Montpelier, Vermont

(802) 828-4528 (voice)
(802) 828-4465 (FAX)
Hours_of_Service: Monday - Friday 9:00 - 5:00 EST
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:

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