Geologic investigation of the Western Tanacross and Taylor Mountain areas, Tanacross and Eagle quadrangles, Alaska

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Frequently anticipated questions:


What does this data set describe?

Title:
Geologic investigation of the Western Tanacross and Taylor Mountain areas, Tanacross and Eagle quadrangles, Alaska
Abstract:
Geologic investigation of the Western Tanacross and Taylor Mountain areas, Tanacross and Eagle quadrangles, Alaska, Preliminary Interpretive Report 2024-6, presents a bedrock geological map of a 4,450-sq-km (1,720-sq-mi) area in eastern Interior Alaska around Mosquito Flats, herein called the Western Tanacross project, and a 2,320-sq-km (900-sq-mi) area around Taylor Mountain and the Mosquito Fork of the Fortymile River, herein called the Taylor Mountain project. The Western Tanacross project area straddles the Alaska Highway northwest of Tok, Alaska and includes most of the Tanacross Quadrangle not previously mapped by DGGS. The Taylor Mountain project lies south and west of Chicken, Alaska and straddles the Taylor Highway northeast of Tok, Alaska. The project includes a portion of the northern Tanacross Quadrangle as well as parts of the southern Eagle Quadrangle. DGGS and the U.S. Geological Survey (USGS) identified these map areas as having the potential to host deposits of multiple critical minerals, as well as conventional mineral resources, including gold, copper, molybdenum, lead, zinc, and silver. Most of the known mineralization in both project areas is related to Mesozoic-Paleogene magmatism, which includes diverse compositions, emplacement depths, and varying intrusion sizes. Igneous rocks intrude a composite metamorphic province that includes both parautochthonous North America and the allochthonous Yukon Tanana Terrane, which are both multiply deformed and apparently juxtaposed along low-angle faults. The complete report, geodatabase, and ESRI fonts and style files are available from the Alaska Division of Geological & Geophysical Surveys website: http://doi.org/10.14509/31166.
Supplemental_Information:
This geodatabase is organized according to the AK GeMS mapping schema Hendricks, M.D., Macpherson, A.E., Athey, J.E., Wyatt, W.C., Montayne, Simone, Buchanan, Wes, Rivera, P.G., and Steinleitner, A.M., 2024, AK GeMS data dictionary: A description of the Alaska geologic mapping schema: Alaska Division of Geological & Geophysical Surveys Miscellaneous Publication 170 v. 2, 13 p. https://doi.org/10.14509/31172. 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?
    Naibert, T.J. (ed.), 2024, Geologic investigation of the Western Tanacross and Taylor Mountain areas, Tanacross and Eagle quadrangles, Alaska: Preliminary Interpretive Report PIR 2024-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -144.105473
    East_Bounding_Coordinate: -141.626887
    North_Bounding_Coordinate: 64.258612
    South_Bounding_Coordinate: 63.232636
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2021
    Ending_Date: 2024
    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: 7
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -141
      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 1/298.257222101.
  7. How does the data set describe geographic features?
    w_tanacross_and_taylor_mnt_ak_gems_db
    Geodatabase, layer files, style files, and fonts (Source: DGGS)
    w_tanacross_and_taylor_mnt_gems_db
    Geodatabase, layer files, style files, and fonts (Source: DGGS)
    w_tanacross_and_taylor_mnt_gems_shapefile
    Shapefiles and open data files (Source: DGGS)

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 would like to thank Wes Buchanan for thorough and constructive reviews of the geologic maps, map unit descriptions, and report. We are grateful to have had access to Doyon Limited lands within the study area. The DGGS Western Tanacross project was jointly funded by the U.S. Geological Survey's Earth Mapping Resources Initiative (Earth MRI) program through cooperative agreement G20AC00156 and the State of Alaska. The DGGS Taylor Mountain project was jointly funded by the U.S. Geological Survey's Earth MRI program through cooperative agreement G21AC00336 and the State of Alaska. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Geological Survey. Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.
  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?

The purpose of this product is to produce more accurate and modern geologic maps and supporting datasets that will promote mineral resource exploration in eastern Interior Alaska. The map area is of current and historic interest for potential mineral resource development, including quartz vein Au mineralization, placer Au deposits, granite-hosted tin mineralization, and intrusion related Cu-Au deposits.

How was the data set created?

  1. From what previous works were the data drawn?
    Hendricks, M.D. and others, 2024 (source 1 of 3)
    Hendricks, M.D., Macpherson, A.E., Athey, J.E., Wyatt, W.C., Montayne, Simone, Buchanan, Wes, Rivera, P.G., and Steinleitner, A.M., 2024, AK GeMS data dictionary: A description of the Alaska geologic mapping schema: Miscellaneous Publication MP 170 v. 2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 13 p
    Type_of_Source_Media: paper
    Source_Contribution: GIS analysis and digital cartography
    Macpherson, A.E. and others, 2024 (source 2 of 3)
    Macpherson, A.E., Hendricks, M.D., and Athey, J.E., 2024, AK GeMS Symbology: A description of the AK GeMS Style File: Miscellaneous Publication MP 169 v. 2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 6 p
    Type_of_Source_Media: paper
    Source_Contribution: GIS analysis and digital cartography
    U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020 (source 3 of 3)
    U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020, GeMS (Geologic Map Schema) - A standard format for the digital publication of geologic maps: Techniques and Methods TM 11-B10, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: 1 p
    Type_of_Source_Media: paper
    Source_Contribution: GIS analysis and digital cartography
  2. How were the data generated, processed, and modified?
    Date: 2022 (process 1 of 2)
    Geologic mapping - The Western Tanacross and Taylor Mountain maps and associated geologic reports are a product of 460 person-days of helicopter-supported fieldwork completed during the summers of 2021 and 2022, plus compilation and reinterpretation of existing geologic maps (Foster, 1967; Foster, 1970; Foster, 1976). Age assignments for igneous and metaigneous map units are supported by 38 new U-Pb zircon ages completed as part of this study (Gavel and others, 2023). Cooling ages of metamorphic rocks, hydrothermal alteration ages, and crystallization ages for select igneous rocks are informed by 22 new 40Ar/39Ar ages (Naibert and others, 2023). Seven detrital zircon analyses were conducted to better understand Cretaceous sedimentary rocks and Paleozoic-Proterozoic metasedimentary rocks in the study area (Gavel and others, 2023). All cited age uncertainties are reported at 2-sigma, and uncertainties have been converted from their original sources to 2-sigma where applicable. We used geochemical data, including 388 whole-rock analyses (Wypych and others, 2022a, 2022b), more than 300 slab X-ray fluorescence (XRF) analyses, and more than 2,500 handheld XRF analyses, to describe, classify, and map the distribution of different lithologies in both map areas. In addition to our own data, this map is built on open exchange of data and ideas with our colleagues at the USGS Alaska Science Center. The accompanying report provides a comprehensive bibliographic reference list of prior work used to identify and delineate rock units and structural elements.
    Date: 2024 (process 2 of 2)
    GIS analysis and digital cartography - This data distribution package's geologic and geographic features were organized and attributed according to the AK GeMS geologic mapping schema. The data were programmatically transformed to provide download options in three formats: (1) an AK GeMS data package that includes the complete AK GeMS database and associated files, (2) a GeMS data package that is a conversion of the AK GeMS database into the base GeMS standard published by the USGS, and (3) a shapefile data package that includes two simple shapefile representations of the data. Data sources used in this process:
    • Hendricks, M.D. and others, 2024
    • Macpherson, A.E. and others, 2024
    • U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020
  3. What similar or related data should the user be aware of?
    Gavel, M.M., Regan, S.P., Holland, Mark, Wildland, A.D., Wypych, Alicja, Naibert, T.J., and Twelker, Evan, 2023, U-Pb zircon geochronology of bedrock samples collected in the Eagle and Tanacross quadrangles, eastern Alaska: Preliminary Interpretive Report PIR 2023-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 38 p
    Gavel, M.M., Wypych, Alicja, Naibert, T.J., Avirett, D.F., Barrera, M.L., Hubbard, A.K., Newberry, R.J., Regan, S.P., Twelker, Evan, Wildland, A.D., and Wyatt, W.C., 2022, Field station locations and magnetic susceptibility data collected in 2020 and 2021 for the Western Tanacross project, Tanacross and Eagle quadrangles, Alaska: Raw Data File RDF 2022-3, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 p
    Gavel, M.M., Wypych, Alicja, Naibert, T.J., Avirett, D.F., Barrera, M.L., Hubbard, A.K., Newberry, R.J., Regan, S.P., Twelker, Evan, Wildland, A.D., and Wyatt, W.C., 2022, Field station locations and magnetic susceptibility data collected in 2021 for the Taylor Mountain project, Tanacross and Eagle quadrangles, Alaska: Raw Data File RDF 2022-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 p
    Naibert, T.J., Heizler, M.T., Newberry, R.J., Twelker, Evan, and Wypych, Alicja, 2023, 40Ar/39Ar geochronology data from the Tanacross and Eagle quadrangles, Alaska: Raw Data File RDF 2023-23, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 19 p
    Wypych, Alicja, Gavel, M.M., Naibert, T.J., Avirett, D.F., Barrera, M.L., Hubbard, A.K., Newberry, R.J., Regan, S.P., Twelker, Evan, Wildland, A.D., and Wyatt, W.C., 2022, Geochemical data from samples collected in 2020 and 2021 for the Western Tanacross project, Tanacross Quadrangle, Alaska: Raw Data File RDF 2022-5, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 3 p
    Wypych, Alicja, Gavel, M.M., Naibert, T.J., Avirett, D.F., Barrera, M.L., Hubbard, A.K., Newberry, R.J., Regan, S.P., Twelker, Evan, Wildland, A.D., and Wyatt, W.C., 2022, Geochemical data from samples collected in 2021 for the Taylor Mountain project, Tanacross and Eagle quadrangles, Alaska: Raw Data File RDF 2022-4, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 3 p

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

  1. How well have the observations been checked?
    Attribute fields within each feature class are populated using the map symbology and corresponding applicable values from the GeMS and AK GeMS specifications. When known, certainty in attribute interpretation is indicated in the relevant fields. Attribute accuracy varies throughout the map and is scale-dependent.
  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 a DGGS Preliminary Interpretive Report (PIR). A PIR provides timely release of maps and reports with a preliminary interpretation of geology or analytical data. Several scientists familiar with the geology of map area reviewed this product for general readability and logical consistency, but it has not undergone technical peer review.
  5. How consistent are the relationships among the observations, including topology?
    All polygon features were topologically validated according to the AK GeMS geologic mapping schema specifications.

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? PIR 2024-6
  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: 07-Jan-2025
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 Tue Jan 07 16:27:56 2025