Bonnifield mining district electromagnetic and magnetic airborne geophysical survey, data compilation

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Frequently anticipated questions:


What does this data set describe?

Title:
Bonnifield mining district electromagnetic and magnetic airborne geophysical survey, data compilation
Abstract:
The Bonnifield electromagnetic and magnetic airborne geophysical survey data were acquired in 2006 and 2007 with a DIGHEM-V Electromagnetic (EM) system and a cesium magnetometer. The EM and magnetic sensors were flown at a height of 30 meters (m). In addition the survey recorded data from radar and laser altimeters, a GPS navigation system, 50/60 Hz monitors and a video camera. Flights were performed with an AS-350-B3 Squirrel helicopter at a mean terrain clearance of 60 m along N-S survey flight lines with a spacing of 400 m. Tie lines were flown perpendicular to the flight lines at intervals of approximately 4,800 m for part of the Bonnifield mining district in Interior Alaska. Aeromagnetic and electromagnetic data were acquired for 613 sq miles during the helicopter-based survey. These new data were combined with a geophysical survey of the Liberty Bell area released in 2002 by DGGS. The merged grids and maps are included in this dataset.
Supplemental_Information:
:
Project Name:	Bonnifield
Contracting Agency:	State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (DGGS)
DGGS Section:	Mineral Resources section
Program:	Alaska Airborne Geophysical/Geological Mineral Inventory Program
Funding Source:	Alaska State Legislature
Contractor:	Stevens Exploration Management Corp.
Survey Flown By:	Fugro Airborne Surveys Corp. now CGG (year 2015)
Fugro Project Number:	6061
DGGS Contract Manager:	Laurel E. Burns
Data Acquisition:	Digitally acquired
Line miles (km):	2811.8 miles (4525.2 km)
Data Acquisition:
Start Date (YYYY-MM-DD):	2006-10-02
End Date   (YYYY-MM-DD):	2007-02-02
Platform:	Helicopter
Platform: Model:	AS-350-B3 turbine
Survey Altitude Model:	Mean terrain clearance (height above ground)
Nominal Helicopter Height:	58 meters
Nominal Bird Height:	30 meters
Traverse: Line Azimuth:    	0 degrees / 180 degrees
Traverse: Line Spacing:	1/4 mile (400 meters)
Tie: Line Azimuth:	90 degrees / 270 degrees
Tie: Line Spacing:	approximately 3 miles (approximately 4800 meters)
Border lines:	present around all non-parallel and non-perpendicular edges
Magnetics: Magnetometer:   	Fugro D1344 processor with ScintrexCS3 sensor, mounted in bird
Electromagnetics: Sensor Model:	Dighem(V)
Navigation System: Sensor:	Novatel OEM4 Global Positioning System
Navigation System: Method:	Post-flight differential positioning
Additional equipment: 	Radar and laser altimeters, video camera, and 50/60 Hz monitors
:
Operating frequencies used for the Dighem (V) system.
:
Atm2   orientation   nominal     actual and dipole moments  separation
211    coaxial     / 1000 Hz     1114 Hz                     8 meters
211    coplanar    / 900 Hz      916 Hz                      8 meters
67     coaxial     / 5500 Hz     5523 Hz                     8 meters
56     coplanar    / 7200 Hz     7026 Hz                     8 meters
15     coplanar    / 56,000 Hz   55840 Hz                    8 meters
:
FLIGHT AND LINE NAMING
:
Example: L11020:29082
:
L = L for transverse(production) T for tie(cross)
1 = Area
1 = Line number digit 1
0 = Line number digit 2
2 = Line number digit 3
0 = Reflight number
:
2 = System number digit 1
9 = System number digit 2
0 = Flight number digit 1
8 = Flight number digit 2
2 = Flight number digit 3
:
Example: T15021:3089
:
T = T for tie(cross) L for transverse(production)
1 = Area
5 = Line number digit 1
0 = Line number digit 2
2 = Line number digit 3
1 = Reflight number
:
3 = System number digit 1
0 = Flight number digit 1
8 = Flight number digit 2
9 = Flight number digit 3
:
:
We provide an index map showing the locations of the 1:63,360-scale map sheets that are included on this publication. Two sheets are needed to cover the area. Bounding coordinates for the sheets are given immediately below. The bounding coordinates of the gridded data differ from those of the individual map sheets.
1:63,360-scale maps, sheet 1 West, -148.83
1:63,360-scale maps, sheet 1 East, -147.92
1:63,360-scale maps, sheet 1 North, 64.17
1:63,360-scale maps, sheet 1 South, 63.83
1:63,360-scale maps, sheet 2 West, -147.92
1:63,360-scale maps, sheet 2 East, -147.00
1:63,360-scale maps, sheet 2 North, 64.17
1:63,360-scale maps, sheet 2 South, 63.83
  1. How should this data set be cited?

    Burns, L.E., Fugro Airborne Surveys Corp., Stevens Exploration Management Corp., Graham, G.R.C., and Emond, A.M., 2016, Bonnifield mining district electromagnetic and magnetic airborne geophysical survey, data compilation: Geophysical Report GPR 2016-1, State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (DGGS), Fairbanks, AK, USA.

    Online Links:

    Other_Citation_Details: 1 sheet.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -149.16
    East_Bounding_Coordinate: -147.03
    North_Bounding_Coordinate: 64.24
    South_Bounding_Coordinate: 63.85

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: Oct-2006
    Ending_Date: Apr-2007
    Currentness_Reference: publication date

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: raster digital data, tabular digital data, vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

    2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 6
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -147
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000
      False_Northing: 0

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.01
      Ordinates (y-coordinates) are specified to the nearest 0.01
      Planar coordinates are specified in meters

      The horizontal datum used is North American Datum of 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.4.
      The flattening of the ellipsoid used is 1/294.978698.

  7. How does the data set describe geographic features?

    ascii_data
    ascii format final and raw data with readme files, ascii format gridded data, Geosoft format import template with extension .iO for final ascii data (Source: Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    databases_geosoft
    Geosoft format database file with extension .gdb (Source: Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    documents
    Final report, gridded data explanations, survey background information (Source: Alaska Division of Geological & Geophysical Surveys (DGGS), Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    grids_ermapper
    Geographically registered gridded data, ErMapper ERS format. (Source: Alaska Division of Geological & Geophysical Surveys (DGGS), Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    grids_geosoft
    Geosoft-format binary grids, these grids can be viewed in ESRI ArcMap using a free plugin from Geosoft. Additional explanatory information is included with the download files. (Source: Alaska Division of Geological & Geophysical Surveys (DGGS), Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    images_registered
    GeoTiff format images of all gridded data. Additional explanatory information is included with the download files. (Source: Alaska Division of Geological & Geophysical Surveys (DGGS), Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    kmz
    Google Earth kmz files of all gridded data. (Source: Alaska Division of Geological & Geophysical Surveys (DGGS), Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    maps_pdf_format
    Print format maps in pdf format (Source: Alaska Division of Geological & Geophysical Surveys (DGGS), Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    maps_prn_format
    Print format maps in HPGL/G printer file format with extension .prn. (Source: Alaska Division of Geological & Geophysical Surveys (DGGS), Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    profiles_stacked
    Electromagnetic and magnetic data profiles with EM anomalies. (Source: Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    vector_data
    line path, data contours, em anomalies, interpretation and survey boundary in ESRI shape file (SHP) and Autocad (2000) DXF formats (Source: Alaska Division of Geological & Geophysical Surveys (DGGS), Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)

    video_flightpath
    Survey flight path downward facing video. Available in .avi format. (Source: Alaska Division of Geological & Geophysical Surveys (DGGS), Fugro Airborne Surveys Corp. and Stevens Exploration Management Corp.)


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    The Alaska State Legislature provided funding for the 2007 geophysical data through the Alaska Geophysical/Geological Mineral Inventory Project, a Capital Improvement Project.

  3. To whom should users address questions about the data?


Why was the data set created?

The Bonnifield survey was part of the Alaska Airborne Geophysical/Geological Mineral Inventory project funded by the Alaska State Legislature and managed by State of Alaska, Department of Natural Resources (DNR), Division of Geological & Geophysical Surveys (DGGS). The project seeks to catalyze private-sector mineral development investment. The project delineates mineral zones on Alaska state lands that: 1) have major economic value; 2) can be developed in the short term to provide high quality jobs for Alaska; and 3) will provide economic diversification to help offset the loss of Prudhoe Bay oil revenue.


How was the data set created?

  1. From what previous works were the data drawn?

    Akima, 1970 (source 1 of 2)
    Akima, H., 1970, A new method of interpolation and smooth curve fitting based on local procedures: Journal of the Association of Computing Machinery v. 7, no. 4.

    Online Links:

    • None

    Type_of_Source_Media: paper
    Source_Contribution:
    Fugro Airborne Surveys used a modification of this method while making grids

    Fugro Airborne Surveys, 2002 (source 2 of 2)
    Fugro Airborne Surveys Corp., Unpublished material, DVD containing original raw and processed data, and vector files for the Liberty Bell area, western Bonnifield mining district, central Alaska.

    Type_of_Source_Media:
    tabular digital data, raster digital data, vector digital data on DVD
    Source_Contribution:
    A copy of the original raw and final geophysical data from the 2001-2002 Liberty Bell survey and other associated files are stored at the office of Fugro Airborne Surveys. Rather than using versions released by DGGS in 2002, Fugro used the files already available to them to provide data for the merged grids included on this publication.

  2. How were the data generated, processed, and modified?

    Date: 2007 (process 1 of 14)
    The 2006-2007 airborne geophysical data were acquired with a DIGHEM(V) Electromagnetic (EM) system and a Fugro D1344 cesium magnetometer with a Scintrex CS3 censor. The EM and magnetic sensors were flown at a height of 100 feet. In addition, the survey recorded data from a radar altimeter, GPS navigation system, 50/60 Hz monitors, and video camera. Flights were performed with an AS350B-3 Squirrel helicopter at a mean terrain clearance of 200 feet along N-S survey flight lines with one-quarter mile line spacing. Tie lines were flown perpendicular to the flight lines at intervals of approximately 3 miles. A Novatel OEM4 Global Positioning System was used for navigation and flight path recovery. The helicopter position was derived every 0.5 seconds using post-flight differential positioning to a relative accuracy of better than 5 m. Flight path positions were projected onto the Clarke 1866 (UTM zone 6) spheroid, 1927 North American datum using a central meridian (CM) of 147 degrees, a north constant of 0 and an east constant of 500,000.

    Date: 2007 (process 2 of 14)
    The total magnetic field data were acquired with a sampling interval of 0.1 seconds, and were (1) corrected for measured system lag, (2) corrected for diurnal variations by subtraction of the digitally recorded base station magnetic data (saved as tfmag in bonnifield_linedata.xyz), (3) adjusted for regional variations (or IGRF gradient, 2005, updated to November 2006) using altimeter adjusted IGRF, (4) leveled to the tie line data (saved as magigrf in bonnifield_linedata.xyz), and (5) interpolated onto a regular 80m grid using a modified Akima (1970) technique. The new magnetic data and the Liberty Bell magnetic data were then gridded together to create the merged magnetic grid.

    Data sources used in this process:

    • Akima, 1970
    • Fugro Airborne Surveys, 2002

    Date: 2007 (process 3 of 14)
    The total magnetic field data were subjected to a processing algorithm that enhances the response of magnetic bodies in the upper 500 m and attenuates the response of deeper bodies. The resulting calculated first vertical derivative(vertical gradient grid(*cvg.grd)) provides better definition and resolution of near-surface magnetic units. It also identifies weak magnetic features that may not be evident on the total field data.

    Data sources used in this process:

    • Akima, 1970
    • Fugro Airborne Surveys, 2002

    Date: 2007 (process 4 of 14)
    The DIGHEM V EM system measured inphase and quadrature components at five frequencies. Two vertical coaxial-coil pairs operated at 1114 (1000) and 5523 (5500) Hz while three horizontal coplanar-coil pairs operated at 916 (900), 7026 (7200), and 55,840 (56,000) Hz. The EM data were sampled at 0.1 second intervals. The EM system responds to bedrock conductors, conductive overburden, and cultural sources. The EM inphase and quadrature data were drift corrected using base level data collected at high altitude (areas of no signal). Along-line filters are applied to the data to remove spheric spikes. The data were inspected for variations in phase, and a phase correction +was applied to the data if necessary. Apparent resistivities were then calculated from the inphase and quadrature data for all frequencies based on a pseudo-layer half-space model. Manual leveling of the inphase and quadrature of each coil pair, based on the resistivity data and comparisons to the data from the other frequencies, was performed. Automated micro-leveling is carried out in areas of low signal. The new resistivity data and the Liberty Bell resistivity data were used to create the merged resistivity grids. The EM data were interpolated onto a regular 80m grid using a modified Akima (1970) technique. The resulting grids were subjected to a 3x3 hanning filter before contouring and map production.

    Data sources used in this process:

    • Akima, 1970
    • Fugro Airborne Surveys, 2002

    Date: 2007 (process 5 of 14)
    To produce the digital terrain model, the GPS-Z data were differentially corrected and transformed into the local datum. The ALTBIRD data were filtered using a 13, 13 filter. Both the Z-COR (differentially corrected GPS-Z) was checked for spikes, which were removed manually. The corrected altimeter was then subtracted from the Z-COR data to produce profiles of the height above mean sea level along the survey lines. The data were manually leveled to remove any errors between lines. After all leveling, the data were DC shifted to match the local maps, in this case, NAD27. The final Z value is recalculated as final Z = DTM + altbird.

    Date: 2007 (process 6 of 14)
    The included plot files of the maps were produced by Fugro Airborne Surveys. The HPGL2 files were created with HP Designjet 5000 printer driver v5.32 and will not work with all plotters, but do plot on the DGGS HP Design Jet 5000. The postscript files were produced by Hewlett Packard Designjet 5000 Postcript 3 printer driver v4.293. These postscript files should work with all HP plotters that can read Postscript 3. The HPGL2 files have brighter colors and sharper topography than the postscript files. The Adobe Acrobat format files were created with Adobe Acrobat Distiller v7.0 (PDF 1.3) from the postscript files.

    Date: 2007 (process 7 of 14)
    Discrete anomalous EM responses (EM anomalies) were computer picked from the electromagnetic data set and classified by type and grade. Line and polygon features of the electromagnetic and magnetic data were identified by contractor staff. EM anomalies are presented on map and profile data and are available in ASCII file format. These features are named and stored in geographically registered formats.

    Date: 2016 (process 8 of 14)
    Legacy data compilation - DGGS staff compiled and organized previously published data and the originating data from the contractor. Original vector data were compiled into an ESRI ArcMap File Geodatabase using ArcMap 10.3.1's CAD to Geodatabase tool in batch mode. In this publication's older products and documentation the magnetic data products have been referred to as Total Field Magnetics on the maps and the MAGIGRF channel in the line data and 'magigrf' as a filename abbreviation. The new term 'sim_magtf' has been created to rename and clarify that the data are not representative of the true total magnetic field as the IGRF values have been removed with a single average IGRF value added back to the data, resulting in the IGRF gradient being removed. The term simulated magnetic total field and the filename abbreviation 'sim_magtf' is now used to identify the final magnetic data. Also in this publications older products, the calculated first vertical derivative grids and images were labeled with cvg or named with calculated vertical gradient. This was renamed here to be consistent with the other survey projects.

    Data sources used in this process:

    • Burns, L.E., Fugro Airborne Surveys Corp., and Stevens Exploration Management Corp., 2007

    Date: 2016 (process 9 of 14)
    Data in Geosoft GDB format - These data were created by importing the final ascii data into Geosoft Oasis Montaj v8.5.1 using the created *.iO import file.

    Date: 2016 (process 10 of 14)
    Geographically registered gridded data in Geosoft GRD format - DGGS assigned missing projection info to grids as needed using Geosoft Oasis montaj v8.5.1.

    Date: 2016 (process 11 of 14)
    Geographically registered gridded data in GeoTiff format - These data were created by DGGS using Geosft Oasis montaj v8.5.1. Geosoft grd files were displayed in Geosoft and exported to GeoTiff. A matching colorbar for each grid was displayed in Geosoft and export as a GeoTiff. ER Mapper ERS files were created using Geosoft Oasis montaj v8.5.1 grid copy/convert function from the Geosoft format grids.

    Date: 2016 (process 12 of 14)
    Geographically registered gridded data in Geosoft GRD format - DGGS assigned missing projection info to grids as needed using Geosoft Oasis montaj v8.3. Geosoft Oaisis montaj MAGMAP extension was used to create analytic signal grid.

    Date: 2016 (process 13 of 14)
    Google Earth KMZ files - Created Google Earth KMZ files from the GeoTiff format gridded data using ESRI ArcGIS 10.3.1.

    Date: 2016 (process 14 of 14)
    Boundary polygon - The boundary polygon was generated by loading the final line data in Geosoft Oasis montaj v8.5.1. The final magnetic data was gridded using the Minimum Curvature option with the following settings: grid cell size = 1/5 of line spacing, blanking distance = double the line spacing, cells to extend beyond data = 0. The polygon file was created using Grid Outline tool with edge resolution = 1. The polygon file was exported to ESRI shapefile.

  3. What similar or related data should the user be aware of?

    Alaska Division of Geological & Geophysical Surveys, Fugro Airborne Surveys Corp., Stevens Exploration Management Corp., and Burns, L.E., 2002, Line, grid, and vector data of airborne geophysical survey data for the Liberty Bell area, western Bonnifield mining district, central Alaska: Geophysical Report GPR 2002-7, State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (DGGS), Fairbanks, AK, USA.

    Online Links:

    Other_Citation_Details: 1 DVD
    Athey, J.E., Newberry, R.J., Werdon, M.B., Freeman, L.K., Smith, R.L., and Szumigala, D.J., 2006, Bedrock geologic map of the Liberty Bell area, Fairbanks A-4 Quadrangle, Bonnifield mining district, Alaska: Report of Investigation RI 2006-2 v 1.0.1, State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (DGGS), Fairbanks, AK, USA.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:50,000, 98 pp.


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

  1. How well have the observations been checked?

    Survey contracts specified the conditions and specifications under which these data were collected. Altimeter, heading, lag, and frequent EM calibrations were done. The magnetometer used had a sensitivity of 0.01 nT. Resistivity sensitivity varies among the different frequencies from 0.06 ppm to 0.30 ppm. More information will be available in the project report to be published in the future.

  2. How accurate are the geographic locations?

    The helicopter position was derived every 0.5 seconds using post-flight differential positioning to a relative accuracy of better than 5 m. Positional accuracy of the presented data is better than 10 m with respect to the UTM grid. Further inaccuracies may be introduced by the interpolation and gridding process.

  3. How accurate are the heights or depths?

    The accuracy of the elevation calculation used for the digital terrain model is directly dependent on the accuracy of the two input parameters, ALTR and HMSL. The ALTR value may be erroneous in areas of heavy tree cover, where the altimeter reflects the distance to the tree canopy rather than the ground. The HMSL (or GPS-Z) value is primarily dependent on the number of available satellites. Although post-processing of GPS data will yield X and Y accuracies in the order of 5 meters, the accuracy of the Z value is usually much less, sometimes in the +/-20 meter range.

  4. Where are the gaps in the data? What is missing?

    The file 'bonnifield_linedata.xyz' contains 2004937 records with 28 channels each. Channel names and definitions of all 28 channels are included in 'bonnifield_linedata_readme.txt'.
    The DIGHEM V EM system measured inphase and quadrature components at five frequencies. Two vertical coaxial-coil pairs operated at 1114 (1000) and 5523 (5500) Hz while three horizontal coplanar-coil pairs operated at 916 (900), 7026 (7200), and 55,840 (56,000) Hz. The EM data were sampled at 0.1 second intervals. The EM system responds to bedrock conductors, conductive overburden, and cultural sources. The power line monitors and the flight track video were examined to locate cultural sources.
    The total magnetic field data were acquired with a sampling interval of 0.1 seconds, and were (1) corrected for measured system lag, (2) corrected for diurnal variations by subtraction of the digitally recorded base station magnetic data (saved as tfmag in bonnifield_linedata.xyz), (3) adjusted for regional variations (or IGRF gradient, 2005, updated to November 2006) using altimeter adjusted IGRF, (4) leveled to the tie line data (saved as magigrf in bonnifield_linedata.xyz), and (5) interpolated onto a regular 80m grid using a modified Akima (1970) technique.
    CHANNELS WITH MISSING VALUES IN 'bonnifield_linedata.xyz' Channel Data Null Values Values

    *****************************************
    :   x           4,009,874               0
    :   y           4,009,874               0
    :   FID         4,009,846              28
    :   latitude    4,009,874               0
    :   longitude   4,009,874               0
    :   flight      4,009,846              28
    :   altbird     4,009,846              28
    :   dem         4,009,866               8
    :   magigrf     4,008,806           1,068
    :   tfmag       4,008,814           1,060
    :   cpi900      4,009,658             216
    :   cpq900      4,009,658             216
    :   cxi1000     4,009,658             216
    :   cxq1000     4,009,658             216
    :   cxi5500     4,009,658             216
    :   cxq5500     4,009,658             216
    :   cpi7200     4,009,858              16
    :   cpq7200     4,009,858              16
    :   cpi56k      4,009,658             216
    :   cpq56k      4,009,658             216
    :   res900      4,008,450           1,424
    :   DEP900      3,718,652         291,222
    :   RES7200     4,008,578           1,296
    :   DEP7200     3,938,644          71,230
    :   RES56K      4,007,892           1,982
    :   DEP56K      3,987,350          22,524
    :   DIFI        4,009,658             216
    :   DIFQ        4,009,658             216
    
    Missing magnetic values occur in the Bonnifield database for the typical reasons of the lagging process, at the beginning of some lines, and due to despiking. The Bonnifield data has a number of magnetic dropouts. When the missing interval is too wide to comfortably interpolate, the area is left as dummies in the database. When the profile gaps are extensive enough, the gridding does not spline across them.

  5. How consistent are the relationships among the observations, including topology?

    Data for this survey were collected by a single subcontractor (Fugro Airborne Surveys) who was responsible for collecting and processing the data. All the data were collected with the same instruments (magnetometers, electromagnetic bird and sensors, gamma ray spectrometer, altimeters, and navigational system).


How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints:
This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).
Use_Constraints:
Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.

  1. Who distributes the data set? (Distributor 1 of 1)

    Alaska Division of Geological & Geophysical Surveys
    3354 College Road
    Fairbanks, AK 99709-3707
    USA

    (907)451-5020 (voice)
    (907)451-5050 (FAX)
    dggspubs@alaska.gov

    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays
    Contact_Instructions:
    Please view our website (<http://www.dggs.alaska.gov>) for the latest information on available data. Please contact us using the e-mail address provided above when possible.
  2. What's the catalog number I need to order this data set?

    GPR 2016-1

  3. What legal disclaimers am I supposed to read?

    The State of Alaska makes no expressed or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 21-Jan-2016
Metadata author:
Alaska Division of Geological & Geophysical Surveys
Metadata Manager
3354 College Road
Fairbanks, AK 99709-3707
USA

(907)451-5020 (voice)

Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:


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