Geology of the Sleetmute A-5, A-6, B-5, and B-6 quadrangles, southwestern Alaska

Metadata also available as - [Parseable text] - [XML]

Frequently anticipated questions:

What does this data set describe?

Title:
Geology of the Sleetmute A-5, A-6, B-5, and B-6 quadrangles, southwestern Alaska
Abstract:
Geology of the Sleetmute A-5, A-6, B-5, and B-6 quadrangles, southwestern Alaska, Professional Report 99, presents a compilation geologic map of the Chuilnuk Mountains and Kiokluk Mountains in the Kuskokwim Mountains area of southwestern Alaska. Geologic mapping of the Sleetmute quadrangles in southwestern Alaska utilized detailed topographic maps, aerial photographs, and field data from U.S. Geological Survey studies, with key contributions published in 1984 and supplemented by Alaska DGGS data files. The region's geology spans from the Late Proterozoic to the Holocene, with the oldest rocks informally grouped under the broadly defined Holitna Group. Most of the area is underlain by the Kuskokwim Group, a thick sequence of marine turbidites primarily dated to the Late Cretaceous. Overlying this is the Holokuk Basalt, a Late Cretaceous volcanic unit associated with granodiorite intrusions, followed by younger dikes and olivine basalt dated at 38 Ma. Quaternary deposits record four glacial advances, and the area exhibits complex folding and faulting tied to the Denali-Farewell fault system. The lower Kuskokwim region is rich in mineral resources, including placer deposits of gold and tungsten, and vein and greisen deposits containing mercury, antimony, tin, and other metals. Hydrothermal quartz veins near Fortyseven Creek host gold and scheelite, likely formed by a rhyolite intrusion. Mercury and antimony deposits, such as the Mountain Top site, occur in sheared and brecciated rocks, possibly linked to hot spring activity. Tin is found in quartz-tourmaline veins and stockworks near pluton contacts, with mineralized zones showing distinct downstream geochemical signatures.The complete report, geodatabase, and ESRI fonts and style files are available from the Alaska Division of Geological & Geophysical Surveys website: http://doi.org/10.14509/2280.
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?
    Decker, J.E., Reifenstuhl, R.R., Robinson, M.S., Waythomas, C.F., and Clough, J.G., 1995, Geology of the Sleetmute A-5, A-6, B-5, and B-6 quadrangles, southwestern Alaska: Professional Report PR 99, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 16 p., 3 sheets
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -158.261453
    East_Bounding_Coordinate: -157.477051
    North_Bounding_Coordinate: 61.505893
    South_Bounding_Coordinate: 60.993776
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1955
    Ending_Date: 2026
    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: 4
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -159
      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 NAD27.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.4.
      The flattening of the ellipsoid used is 1/294.9786982.
  7. How does the data set describe geographic features?
    sleetmute_a5_a6_b5_b6_quads_geo_ak_gems_db
    Geodatabase, layer files, style files, and fonts (Source: DGGS)
    sleetmute_a5_a6_b5_b6_quads_geo_gems_db
    Geodatabase, layer files, style files, and fonts (Source: DGGS)
    sleetmute_a5_a6_b5_b6_quads_geo_geo_gems_geopackage
    SQLite Database file (Source: DGGS)
    sleetmute_a5_a6_b5_b6_quads_geo_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?
    Kinney Engineering, LLC staff used scanned and georeferenced paper maps to digitize geologic features into an AK GeMS database. Chris Wyatt conducted quality control of this digitizing work and completed the creation of the AK GeMS database. Ally M. Steinleitner conducted final database quality control and packaging. This geologic map (or report or conversion or product, etc.) was funded by the USGS National Cooperative Geologic Mapping Program under STATEMAP award number G23AC00584, 2023, and the State of Alaska General Fund. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government.
  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 research was to investigate the mineralization within the lower Kuskokwim River basin in southwest Alaska. The study aimed to assess the geologic context, resource potential, and development history of these deposits. Additional objectives included evaluating local sand, gravel, and riprap resources for potential use in regional infrastructure projects.

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: 1995 (process 1 of 2)
    Geologic mapping - Geologic mapping efforts employed 1:40,000-scale topographic base maps, 1:63,360-scale aerial photographs, and field data from earlier U.S. Geological Survey studies. A reconnaissance study by Cady et al. (1955) included these quadrangles. Preliminary geologic maps for Sleetmute A-6, B-5, and B-6 were published in 1984 by various authors, and geochemical maps for rock, pan-concentrate, and stream sediment samples were compiled by Robinson in the same year.
    Date: 2026 (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?
    Bundtzen, T.K., Harris, E.E., Miller, M.L., Layer, P.W., and Laird, G.M., 1999, Geology of the Sleetmute C-7, C-8, D-7, and D-8 quadrangles, Horn Mountains, southwestern Alaska: Report of Investigation RI 98-12, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 38 p., 3 sheets, scale 1:63,360
    Bundtzen, T.K., Laird, G.M., Harris, E.E., Kline, J.T., and Miller, M.L., 1993, Geologic map of the Sleetmute C-7, D-7, C-8, and D-8 quadrangles, Horn Mountains area, southwest Alaska: Public Data File PDF 93-47, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 15 p., 2 sheets, scale 1:63,360
    Burns, L.E., Graham, G.R.C., Barefoot, J.D., Surveys, Fugro Airborne, and Stevens Exploration Management Corp., 2019, Sleetmute electromagnetic and magnetic airborne geophysical survey data compilation: Geophysical Report GPR 2019-16, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 13 p
    Collazzi, E.J., and Ireland, R.R.W., 1986, Hydrologic reconnaissance of the Kuskokwim River basin between Sleetmute and Aniak, Alaska 1982-1983: Report of Investigation RI 86-16, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:385,000
    Decker, J.E., Reifenstuhl, R.R., and Coonrad, W.L., 1984, Compilation of geologic data from the Sleetmute A-5 Quadrangle, southwestern Alaska: Report of Investigation RI 84-29, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:63,360
    Decker, J.E., Reifenstuhl, R.R., and Coonrad, W.L., 1984, Compilation of geologic data from the Sleetmute B-5 Quadrangle, southwestern Alaska: Public Data File PDF 84-44, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 7 p., 1 sheet, scale 1:63,360
    Decker, J.E., Reifenstuhl, R.R., and Coonrad, W.L., 1985, Compilation of geologic data from the Sleetmute A-7 Quadrangle, southwestern Alaska: Report of Investigation RI 85-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:63,360
    Decker, J.E., Robinson, M.S., Murphy, J.M., Reifenstuhl, R.R., and Albanese, M.D., 1984, Geologic map of the Sleetmute A-6 Quadrangle, Alaska: Report of Investigation RI 84-8, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:40,000
    Krause, K.J., 1984, Photointerpretive map of morphological flood-plain deposits and materials resources, middle Kuskokwim River from Sleetmute to Kalskag: Report of Investigation RI 84-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 4 p., 5 sheets, scale 1:63,360
    Murphy, J.M., Decker, J.E., Reifenstuhl, R.R., and Coonrad, W.L., 1984, Compilation of geologic data from the Sleetmute B-6 Quadrangle, southwestern Alaska: Public Data File PDF 84-45, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 9 p., 1 sheet, scale 1:63,360
    Reger, R.D., Campbell, K.M., Stevens, D.S.P., and Smith, R.L., 2003, Survey of geology, geologic materials, and geologic hazards in proposed access corridors in the Sleetmute Quadrangle, Alaska: Miscellaneous Publication MP 109, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 4 sheets, scale 1:250,000
    Reifenstuhl, R.R., Decker, J.E., Murphy, J.M., and Coonrad, W.L., 1984, Compilation of geologic data from the Sleetmute A-6 Quadrangle, southwestern Alaska: Public Data File PDF 84-43, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:63,360
    Reifenstuhl, R.R., Robinson, M.S., Smith, T.E., Albanese, M.D., and Allegro, G.L., 1984, Geologic map of the Sleetmute B-6 Quadrangle, Alaska: Report of Investigation RI 84-12, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:40,000
    Robinson, M.S., 1984, Rock, pan concentrate, and stream-sediment geochemistry, Sleetmute B-5 Quadrangle: Report of Investigation RI 84-9, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:40,000
    Robinson, M.S., 1984, Rock, pan-concentrate, and stream-sediment geochemistry, Sleetmute A-6 Quadrangle: Report of Investigation RI 84-7, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:40,000
    Robinson, M.S., 1984, Rock, pan-concentrate, and stream-sediment geochemistry, Sleetmute B-6 Quadrangle: Report of Investigation RI 84-11, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:40,000
    Robinson, M.S., 1986, Basic statistical analysis of geochemical results for rock, pan-concentrate, and stream-sediment samples from the Sleetmute A-5, A-6, B-5, and B-6 quadrangles, southwest Alaska: Public Data File PDF 86-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 81 p
    Robinson, M.S., and Decker, J.E., 1986, Preliminary age dates and analytical data for selected igneous rocks from the Sleetmute, Russian Mission, Taylor Mountains, and Bethel quadrangles, southwestern Alaska: Public Data File PDF 86-99, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 8 p
    Robinson, M.S., Decker, J.E., Reifenstuhl, R.R., Murphy, J.M., and Box, S.E., 1984, Geologic map of the Sleetmute B-5 Quadrangle, Alaska: Report of Investigation RI 84-10, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:40,000
    Robinson, M.S., Nye, C.J., and Decker, J.E., 1986, Preliminary whole rock major oxide and trace element geochemistry of selected igneous rocks from the Sleetmute, Russian Mission, and Taylor Mountains quadrangles, southwestern Alaska: Public Data File PDF 86-98, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 8 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 Professional Report (PR). A PR is the completed product of original research and analysis, and PRs 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)
    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? PR 99
  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: 02-Oct-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 Thu Oct 02 11:49:01 2025