Preliminary bedrock geologic map database, northeastern Richardson mining district, Alaska

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Frequently anticipated questions:

What does this data set describe?

Title:
Preliminary bedrock geologic map database, northeastern Richardson mining district, Alaska
Abstract:
During the 2017 field season, geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted geologic mapping and sampling of part of the Richardson mining district southeast of Fairbanks, Alaska. The project area is about 30 miles west of the Pogo gold mine and covers gold exploration activity at the Montecristo and Uncle Sam properties. This work aims to build an improved understanding of the area's geology and controls on gold mineralization for purposes of exploration targeting and mineral-resource assessment. The 260-square-mile map area lies between the Salcha River and Shaw Creek and is bounded by the Trans-Alaska Pipeline access road to the southwest. The area is characterized by forested, moderate-relief hills blanketed by vegetation, loess, and locally, sand dunes. Rock outcrop is less than one percent; consequently, the map interpretation relies heavily on the DGGS East Richardson airborne magnetic and electromagnetic survey as well as rocks collected from pits dug into rocky colluvial deposits below surficial loess or sand. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/30676.
Supplemental_Information:
This geodatabase is organized according to the AK GeMS mapping schema Hendricks, M.D., Ekberg, P.G., Athey, J.E., Wyatt, W.C., Willingham, A.L., and Naibert, T.J., 2021, AK GeMS data dictionary: A description of the Alaska geologic mapping schema: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 170, 10 p. https://doi.org/10.14509/30669. The distribution package includes ESRI fonts and style files, along with usage instructions. Further documentation of the symbology is provided by Ekberg, P.G., Hendricks, M.D., and Athey, J.E., 2021, AK GeMS symbology: A description of the AK GeMS style file: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 169, 7 p. https://doi.org/10.14509/30584
  1. How might this data set be cited?
    Twelker, Evan, Wildland, A.D., Werdon, M.B., Sicard, K.R., Wypych, Alicja, Naibert, T.J., Athey, J.E., Willingham, A.L., and Lockett, A.C., 2021, Preliminary bedrock geologic map database, northeastern Richardson mining district, Alaska: Raw Data File RDF 2021-9, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 4 p.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -146.376046
    East_Bounding_Coordinate: -145.662557
    North_Bounding_Coordinate: 64.555398
    South_Bounding_Coordinate: 64.291956
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2017
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: geodatabase
  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.
    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: 0.999600
      Longitude_of_Central_Meridian: -147
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000.000000
      False_Northing: 0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest .00000001
      Ordinates (y-coordinates) are specified to the nearest .00000001
      Planar coordinates are specified in Meters
      The horizontal datum used is NAD83.
      The ellipsoid used is GRS 80.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257222101000025.
  7. How does the data set describe geographic features?
    richardson_ak_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: Alaska Division of Geological & Geophysical Surveys)

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?
    We thank Dennis McDowell and Pat Smith of Great American Minerals Exploration (GAME) and Bill Cronk and Northern Empire Resources Corp. for sharing data and insights on the district. Thanks also to Richard Lessard, Rainer Newberry, and Dave Larimer for geological discussions. Sumitomo Metal Mining Pogo provided access to the Pogo mine road, and Alyeska Pipeline Service Company granted access to the pipeline right of way. This project was funded by the State of Alaska.
  3. To whom should users address questions about the data?
    Alaska Division of Geological & Geophysical Surveys
    Metadata Manager
    3354 College Road
    Fairbanks, AK
    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 (https://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.

Why was the data set created?

This work aims to build an improved understanding of the area's geology and controls on gold mineralization for purposes of exploration targeting and mineral-resource assessment.

How was the data set created?

  1. From what previous works were the data drawn?
    Burns, L.E. and others, 2006 (source 1 of 6)
    Burns, L.E., Fugro Airborne Surveys Corp., and Stevens Exploration Management Corp., 2006, Line, grid, and vector data and plot files for the airborne geophysical survey data of parts of the east Richardson, Liscum, and Black Mountain areas, interior Alaska: Geophysical Report GPR 2006-5, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 29 sheets, 1 DVD
    Type_of_Source_Media: digital
    Source_Contribution: Bedrock mapping
    Hendricks, M.D. and others, 2020 (source 2 of 6)
    Hendricks, M.D., Ekberg, P.G., Athey, J.E., and Wyatt, W.C., 2020, AK GeMS data dictionary: A description of the AK GeMS database schema: Miscellaneous Publication MP 168, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Type_of_Source_Media: digital
    Source_Contribution: GIS analysis and digital cartography
    Neuendorf, K.K.E. and others, 2011 (source 3 of 6)
    Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., 2011, Glossary of Geology: American Geological Institute, Alexandria, Virginia.

    Online Links:

    Other_Citation_Details: 799 p
    Type_of_Source_Media: digital
    Source_Contribution: GIS analysis and digital cartography
    U.S. Geological Survey, EROS Data Center, 2013 (source 4 of 6)
    U.S. Geological Survey, EROS Data Center, 2013, IFSAR Orthorectified Radar Image (ORI) Alaska: U.S. Geological Survey, Sioux Falls, SD.

    Online Links:

    Type_of_Source_Media: digital
    Source_Contribution: GIS analysis and digital cartography
    Walker, J.D. and others, 2018 (source 5 of 6)
    Walker, J.D., Geissman, J.W., Bowring, S.A., and Babcock, L.E., 2018, Geologic Time Scale v. 5.0: Geological Society of America, Boulder, CO.

    Online Links:

    Type_of_Source_Media: paper
    Source_Contribution: GIS analysis and digital cartography
    Weber, F.R. and others, 1978 (source 6 of 6)
    Weber, F.R., Foster, H.L., Keith, T.E.C., and Dusel-Bacon, Cynthia, 1978, Preliminary geologic map of the Big Delta Quadrangle, Alaska: Open-File Report OF 78-529-A, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:250,000
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 250000
    Source_Contribution: Bedrock mapping
  2. How were the data generated, processed, and modified?
    Date: 2017 (process 1 of 3)
    Bedrock mapping - During the 2017 field season, DGGS geologists conducted geologic mapping and sampling of part of the Richardson mining district southeast of Fairbanks, Alaska. Rock outcrop is less than one percent; consequently, the map interpretation relies heavily on the DGGS East Richardson airborne magnetic and electromagnetic survey as well as rocks collected from pits dug into rocky colluvial deposits below surficial loess or sand. Location data for outcrop observations were collected using GPS-enabled tablets running the ESRI Collector App. Geologic unit identification Data sources used in this process:
    • Burns, L.E. and others, 2006
    • Weber, F.R. and others, 1978
    Date: 2021 (process 2 of 3)
    GIS analysis and digital cartography - The geologic and geographic features portrayed in this data distribution package were organized and attributed according to the AK GeMS geologic mapping schema. Data sources used in this process:
    • Hendricks, M.D. and others, 2020
    • Neuendorf, K.K.E. and others, 2011
    • U.S. Geological Survey, EROS Data Center, 2013
    • Walker, J.D. and others, 2018
    Date: 2021 (process 3 of 3)
    Technical review - The report and accompanying data were evaluated by project staff for general readability and logical consistency but have not undergone technical peer review.
  3. What similar or related data should the user be aware of?
    Graham, G.E., and Jozwik, Diana, 2007, Data tables related to geology and gold mineralization in the Richardson district, east-central Alaska: Raw Data File RDF 2007-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 32 p
    Naibert, T.J., Benowitz, J.A., Wypych, Alicja, Sicard, K.R., and Twelker, Evan, 2018, 40Ar/39Ar data from the Tanacross D-1 and D-2, Big Delta B-4 and B-5, and Mount Hayes A-6 quadrangles, Alaska: Raw Data File RDF 2018-3, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 15 p
    Twelker, Evan, Benowitz, J.A., and Naibert, T.J., 2020, 40Ar/39Ar data from the Richardson mining district, Big Delta Quadrangle, Alaska: Raw Data File RDF 2020-11, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 10 p
    Twelker, Evan, Werdon, M.B., Sicard, K.R., Wypych, Alicja, Naibert, T.J., Athey, J.E., Willingham, A.L., and Lockett, A.C., 2017, Geologic mapping in the Richardson-Uncle Sam area, interior Alaska (presentation): Alaska Miners Association Annual Convention, Anchorage, Alaska, November 7-12, 2017: Poster and Presentation Twelker, Evan and others, 2017, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 37 p
    Twelker, Evan, Wypych, Alicja, Sicard, K.R., Naibert, T.J., Montayne, Simone, Newberry, R.J., and Wyatt, W.C., 2018, Major-oxide and trace-element geochemical data from rocks collected in the Richardson mining district, Big Delta Quadrangle, Alaska: Raw Data File RDF 2018-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 4 p
    Twelker, Evan, Wypych, Alicja, Sicard, K.R., Naibert, T.J., Werdon, M.B., Athey, J.E., Willingham, A.L., and Lockett, A.C., 2017, Major-oxide and trace-element geochemical data from rocks collected in the Richardson mining district, Big Delta Quadrangle, Alaska: Raw Data File RDF 2017-11, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 4 p
    Twelker, Evan, and O'Sullivan, P.B., 2021, U-Pb zircon data and ages for bedrock samples from the Richardson mining district, Big Delta Quadrangle, Alaska: Raw Data File RDF 2020-14, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 17 p

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

  1. How well have the observations been checked?
    Certainty in attribute interpretation varies throughout the map and is scale dependant. Attribute fields within each feature class record the authors' degree of confidence in the existence or identity of applicable features.
  2. How accurate are the geographic locations?
    Certainty in feature boundaries or location varies throughout the map. Data fields within each feature class and the accompanying orientation and location confidence lookup tables record the authors' degree of confidence in the location of applicable features.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This publication is released as a DGGS Raw Data File (RDF). Reports in the RDF series present field data and analytical results with limited or no interpretation by DGGS staff or project collaborators. The report and accompanying data have been evaluated by project staff for general readability and logical consistency but have not undergone technical peer review. Information presented in this release is subject to change.
  5. How consistent are the relationships among the observations, including topology?
    All polygon features were topologically validated according to specifications of the AK GeMS geologic mapping schema.

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
    Metadata Manager
    3354 College Road
    Fairbanks, AK
    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 (https://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? RDF 2021-9
  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: 30-Jun-2021
Metadata author:
Alaska Division of Geological & Geophysical Surveys
Attn: Simone Montayne
Metadata Manager
3354 College Road
Fairbanks, AK
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
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:
Generated by mp version 2.9.50 on Wed Jun 30 12:20:45 2021