Geologic map of the Styx River area, Lime Hills C-1 Quadrangle, Western Alaska Range, Alaska

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Frequently anticipated questions:


What does this data set describe?

Title:
Geologic map of the Styx River area, Lime Hills C-1 Quadrangle, Western Alaska Range, Alaska
Abstract:
Report of Investigation 2020-3, Geologic map of the Styx River area, Lime Hills C-1 Quadrangle, Western Alaska Range, Alaska, presents a 1:63,360-scale geologic map of the Styx River area (Lime Hills C-1 Quadrangle) in the western Alaska Range. The Styx River map area is underlain by Late Jurassic to Late Cretaceous Kahiltna assemblage sedimentary rocks. Major plutons include the Late Cretaceous South Fork gabbro and Mount Estelle monzogranite, the Paleocene Crystal Creek granite, McKinley sequence granites, Styx River granite, and the Eocene Merrill Pass granite. Major oxide and trace element data helped differentiate distinct compositions of plutons and refine map contacts. Late Cretaceous granodiorite to gabbro plutons contrast in composition with granites from the Paleocene. Previously unmapped mafic dikes trend generally northwest, while major high-angle fault sets trend northwest, north-south, and north-northeast. Mineralization in the Lime Hills C-1 Quadrangle is dominated by: 1) Au-Cu mineralization associated with the margins of the latest Cretaceous Mount Estelle pluton; 2) widely scattered Ag-bearing polymetallic occurrences associated with dikes, veins, and faults of a range of ages and; 3) the Miocene-age Copper Joe porphyry copper prospect. The dataset contains geologic, structural, stratigraphic, and geochronologic data organized according to the GeMS and AK GeMS mapping schemas. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/30424.
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?
    Sicard, K.R., Wypych, Alicja, Twelker, Evan, Naibert, T.J., Freeman, L.K., Newberry, R.J., Bachmann, E.N., Reioux, D.A., Tuzzolino, A.L., and Wright, T.C., 2022, Geologic map of the Styx River area, Lime Hills C-1 Quadrangle, Western Alaska Range, Alaska: Report of Investigation RI 2020-3, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 51 p., 1 sheet, scale 1:63,360
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -153.380287
    East_Bounding_Coordinate: -153.002173
    North_Bounding_Coordinate: 61.749893
    South_Bounding_Coordinate: 61.498865
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2013
    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: 5
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -153
      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?
    lime_hills_c1_quad_ak_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: DGGS)
    lime_hills_c1_quad_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: DGGS)
    lime_hills_c1_quad_gems_shapefile_pkg
    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?
    The Styx project was funded by the State of Alaska's Strategic and Critical Minerals Assessment project as part of the Airborne Geophysical/Geological Mineral Inventory program (AGGMI), and managed by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (DGGS). This project benefited from unpublished data and discussions with geologists of: The U.S. Geological Survey (USGS) and the Western Alaska Range Project (WARP): Sue Karl, Steve Box, Jamey Jones, Erin Todd, Richard Lease, Garth Graham, Steve Nelson, and Peter Haeussler. Gamble provided an exceptional 1:250,000-scale base map for us to build on from his group's mapping in the 1980's. Insightful property tours, knowledge exchange, and geological data came from: Millrock Resources Inc. (Phil St. George, Kati Gibler), Kiska Metals Corp. (Mike Roberts), West Mountain Gold Inc. (Jim Baughman), and Alaska Earth Sciences (Rob Retherford and Bill Ellis). Argon dating and helpful discussions were conducted by the UAF Geophysical Lab with Jeff Benowitz and Paul Layer. Erin Todd provided isotope work for the Merrill Pass pluton, and valuable collaboration. Our lodging, food, and entertainment was provided by the Perrins Family of Rainy Pass Lodge. Thanks to Loren Leeuw for skilled flying during the field campaign, and to Rusts's Flying Service out of Anchorage for our safe delivery of people and camp supplies. We are grateful to Trish Ekberg and Mike Hendricks for their GIS, database, and cartographic support, and to Simone Montayne for metadata management. Kristen Janssen provided excellent manuscript formatting and layout. We thank Erin Todd and Steve Box for thorough reviews that improved the content and clarity of this report.
  3. To whom should users address questions about the data?
    Alaska Division of Geological & Geophysical Surveys
    GIS Manager
    3354 College Rd
    Fairbanks, AK
    USA

    907-451-5020 (voice)
    dggsgis@alaska.gov
    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays

Why was the data set created?

Styx River area geologic mapping work was implemented as part of an ongoing DGGS program to provide geologic mapping and supporting geochemical, petrologic, and geochronologic data to foster a better understanding of the area's geology and mineral potential.

How was the data set created?

  1. From what previous works were the data drawn?
    Benowitz, J.A. and others, 2014 (source 1 of 7)
    Benowitz, J.A., Layer, P.W., and Sicard, K.R., 2014, 40Ar/39Ar data, Styx River map area, Lime Hills C-1 Quadrangle, Alaska: Raw Data File RDF 2014-21 v. 1.0.1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 13 p
    Type_of_Source_Media: paper
    Source_Contribution: Geologic map compilation
    Burns, L.E. and others, 2019 (source 2 of 7)
    Burns, L.E., Emond, A.M., Fugro Airborne Surveys Corp., and Stevens Exploration Management Corp., 2019, Styx River electromagnetic and magnetic airborne geophysical survey data compilation: Geophysical Report GPR 2019-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 3 p
    Type_of_Source_Media: paper
    Source_Contribution: Geologic map compilation
    Ekberg, P.G. and others, 2021 (source 3 of 7)
    Ekberg, P.G., Hendricks, M.D., and Athey, J.E., 2021, AK GeMS symbology: A description of the AK GeMS style file: Miscellaneous Publication MP 169, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 7 p
    Type_of_Source_Media: paper
    Source_Contribution: GIS analysis and digital cartography
    Gamble, B.M. and others, 2013 (source 4 of 7)
    Gamble, B.M., Richter, D.H., and Lanphere, M.A., 2013, Geologic map of the east half of the Lime Hills 1:250,000-scale quadrangle, Alaska: Open-File Report OF 2013-1090, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:2,500,000
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 2500000
    Source_Contribution: Geologic map compilation
    Hendricks, M.D. and others, 2021 (source 5 of 7)
    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: Miscellaneous Publication MP 170, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 10 p
    Type_of_Source_Media: paper
    Source_Contribution: GIS analysis and digital cartography
    Sicard, K.R. and others, 2014 (source 6 of 7)
    Sicard, K.R., Wypych, Alicja, Twelker, Evan, Bachmann, E.N., Freeman, L.K., Newberry, R.J., Reioux, D.A., Tuzzolino, A.L., and Wright, T.C., 2014, Major-oxide, minor-oxide, and trace-element geochemical data from rocks in the Styx River area, Lime Hills C-1 Quadrangle, Lime Hills, McGrath, Talkeetna, and Tyonek quadrangles, Alaska: Raw Data File RDF 2014-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 4 p
    Type_of_Source_Media: paper
    Source_Contribution: Geologic map compilation
    U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020 (source 7 of 7)
    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: 2013 (process 1 of 2)
    Geologic mapping - This geologic map and report draw on work completed by DGGS in 2013, as well as prior work by the USGS (Gamble and others, 2013). The 2013 DGGS project included approximately 200 person-days of bedrock geologic mapping in the Lime Hills C-1 Quadrangle and at nearby prospects and deposits. DGGS geologists collected 1,863 rock and structure stations using Trimble Juno T41/5 WAAS-enabled GPS devices with a reported location error of 1 m, running ArcGIS for Windows Mobile. Latitude and longitude were collected in the WGS84 datum and are reported in NAD83. The map area is mostly covered by the Styx River airborne magnetic and electromagnetic geophysical survey, which greatly facilitated extrapolation of contacts and faults through areas of surficial deposits, glaciation, and inaccessible terrain. To aid in interpretation of the magnetic survey, geologists collected handheld magnetic susceptibility measurements from outcrop and float in units of Systeme International (SI). Approximately 2 to 6 measurements were taken at each station using Terraplus KT 5, 6, 9, and 10 handheld magnetic susceptibility meters. Measurement surfaces and degree of oxidation varied, and no effort was made to assess or measure the effects of remnant magnetization, therefore, the data should be considered semi-quantitative. Mean values and ranges are reported by map unit in table 1 of the accompanying report. The conceptual framework for the geology incorporates key ideas from preexisting literature with new data and interpretations developed from field mapping and analytical findings. The accompanying map or report provides a comprehensive bibliographic reference list of prior work used to identify and delineate rock units and structural elements.
    Date: 2022 (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:
    • Ekberg, P.G. and others, 2021
    • Hendricks, M.D. and others, 2021
    • U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020
  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?
    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?
    This data release provides legacy geospatial data converted to the GeMS and AK GeMS specifications. The data compilers used map symbology to determine positional accuracy. The data pairs descriptive fields within each feature class with location confidence lookup tables to record the originating authors' degree of confidence in the location of features. When location accuracy values are unavailable, users must infer positional accuracy based on standard geologic mapping practices of the investigation era. Certainty in feature boundaries or location varies throughout the map.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This publication is part of a DGGS Report of Investigations (RI). An RI is the completed product of original research and analysis, and RIs use professional cartography and undergo rigorous peer review, editing, and revision.
  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)
    State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys
    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 (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? RI 2020-3
  3. What legal disclaimers am I supposed to read?
    The State of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services 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, any failure thereof, or otherwise, and 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-Jul-2022
Metadata author:
Simone Montayne
3354 College Road
Fairbanks, AK
USA

907-451-5020 (voice)
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:

Generated by mp version 2.9.50 on Thu Jul 07 20:52:00 2022