Geologic investigation of the Haines-Takshanuk Mountains-Chilkat Peninsula area, Southeast Alaska

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Frequently anticipated questions:


What does this data set describe?

Title:
Geologic investigation of the Haines-Takshanuk Mountains-Chilkat Peninsula area, Southeast Alaska
Abstract:
Geologic investigation of the Haines-Takshanuk Mountains-Chilkat Peninsula area, Southeast Alaska, Preliminary Interpretive Report 2025-4, provides the results of geologic mapping in the Haines-Takshanuk Mountains-Chilkat Peninsula area of Southeast Alaska. The study covers approximately 777 square kilometers across portions of the Skagway A-1, A-2, B-1, B-2, and B-3 quadrangles and culminates in a 1:50,000-scale surficial and bedrock geologic map. Field investigations were conducted at more than 550 stations by helicopter- and boat-supported teams from the Alaska Division of Geological & Geophysical Surveys (DGGS) and the University of Alaska Fairbanks (UAF). Observations included documentation of landform morphology, soil test pit sampling, structural measurements, Schmidt Hammer tests, and collection of rock samples for thin section, geochemical, and petrologic analyses. Organic samples were also obtained for radiocarbon dating. The project was initiated in response to the deadly December 2, 2020, landslide in Haines. The mapping enhances characterization of surficial deposits and bedrock units, provides critical information for landslide hazard assessment and emergency planning, and establishes a foundation for future studies of magmatic and mineralization history in Southeast Alaska. It also builds upon earlier work by Redman and others (1984) and Gilbert (1987, 1988), offering updated insights into the Chatham Strait fault system, Coast shear zone, and Coast Plutonic Complex, thereby strengthening both applied and scientific understanding of the region's geology. 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 Alaska Division of Geological & Geophysical Surveys website: http://doi.org/10.14509/31417.
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?
    Larsen, M.C., Regan, S.P., Bull, K.F., Gillis, R.J., Nicolazzo, J.A., Truskowski, C.M., Walser, S.L., and Darrow, M.M., 2025, Geologic investigation of the Haines-Takshanuk Mountains-Chilkat Peninsula area, Southeast Alaska: Preliminary Interpretive Report PIR 2025-4, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -135.868652
    East_Bounding_Coordinate: -135.287972
    North_Bounding_Coordinate: 59.404854
    South_Bounding_Coordinate: 59.103003
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2022
    Ending_Date: 2025
    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: 8
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -135
      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?
    haines_ak_gems_db
    Geodatabase, layer files, style files, and fonts (Source: DGGS)
    haines_gems_db
    Geodatabase, layer files, style files, and fonts (Source: DGGS)
    haines_gems_geopackage
    SQLite Database file (Source: DGGS)
    haines_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?
    The authors would like to extend their gratitude to John Norton and Cindy Buxton for their generous hospitality, field advice, logistical support, and contributions to the project. Review comments by Trent Hubbard (DGGS) improved and clarified the content of this report. Ally M. Steinleitner implemented final database quality control and packaging. Geologic map conversion to the GeMS standard was funded by the USGS National Cooperative Geologic Mapping Program under STATEMAP award number G21AC10706, 2022, 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 Haines geologic mapping project was initiated in response to the deadly December 2, 2020, landslide in Haines, Alaska. The mapping enhances characterization of surficial deposits and bedrock units, provides critical information for landslide hazard assessment and emergency planning, and establishes a foundation for future studies of magmatic and mineralization history in Southeast Alaska.

How was the data set created?

  1. From what previous works were the data drawn?
    Ekberg, P.G. and others, 2021 (source 1 of 6)
    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
    Gilbert, W.G., 1988 (source 2 of 6)
    Gilbert, W.G., 1988, Preliminary geology of the northern Chilkat Range, southeastern Alaska: Report of Investigation RI 88-8, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:36,200
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 36200
    Source_Contribution: geologic mapping
    Gilbert, W.G. and others, 1987 (source 3 of 6)
    Gilbert, W.G., Burns, L.E., Redman, E.C., and Forbes, R.B., 1987, Preliminary bedrock geology and geochemistry of the Skagway B-3 Quadrangle, Alaska: Report of Investigation RI 87-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 2 sheets, scale 1:36,200
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 36200
    Source_Contribution: geologic mapping
    Hendricks, M.D. and others, 2021 (source 4 of 6)
    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
    Redman, E.C. and others, 1984 (source 5 of 6)
    Redman, E.C., Retherford, R.M., and Hickok, B.D., 1984, Geology and geochemistry of the Skagway B-2 Quadrangle, southeastern Alaska: Report of Investigation RI 84-31, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 34 p., 4 sheets, scale 1:40,000
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 40000
    Source_Contribution: geologic mapping
    U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020 (source 6 of 6)
    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: 2025 (process 1 of 2)
    Geologic mapping - Helicopter- and boat-supported teams from DGGS and the University of Alaska Fairbanks mapped the geology through field observations, interpretation of lidar and aerial imagery, and analysis of samples collected at more than 550 stations. Surficial mapping staff documented landform morphology and material characteristics, excavated and sampled soil test pits, measured structural features in rock outcrops, performed Schmidt Hammer tests, and collected rock samples for thin section, major oxide, and trace element analyses, as well as organic samples for radiocarbon dating. To address outstanding questions about the tectonic history of the region, bedrock mappers conducted targeted geologic and structural investigations in conjunction with new surficial mapping. Their work builds on the geologic mapping of Redman and others (1984), Gilbert and others (1987), and Gilbert (1988). Data sources used in this process:
    • Gilbert, W.G., 1988
    • Gilbert, W.G. and others, 1987
    • Redman, E.C. and others, 1984
    Date: 2025 (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 legacy 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?
    Daanen, R.P., Herbst, A.M., Wikstrom Jones, K.M., and Wolken, G.J., 2021, High-resolution lidar data for Haines, southcentral Alaska, December 8-12, 2020: Raw Data File RDF 2021-4, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 8 p
    Nicolazzo, J.A., Darrow, M.M., Larsen, M.C., and Walser, S.L., 2024, Rock strength properties of the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project, Southeast Alaska: Raw Data File RDF 2024-28, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 4 p
    Nicolazzo, J.A., Darrow, M.M., and Walser, S.L., 2024, Soil index properties and radiocarbon ages of the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project, Southeast Alaska: Raw Data File RDF 2024-27, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 24 p
    Truskowski, C.M., Gillis, R.J., Bull, K.F., and Regan, S.P., 2024, Major-oxide and trace-element analyses for rock samples from the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project, southeast Alaska: Raw Data File RDF 2024-18, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 4 p
    Truskowski, C.M., Walser, S.L., Larsen, M.C., Nicolazzo, J.A., Gillis, R.J., Bull, K.F., Regan, S.P., Darrow, M.M., and Montayne, Simone, 2024, Field station locations and data for the geologic map of the Haines-Takshanuk Mountains-Chilkat Peninsula area STATEMAP project, southeast Alaska, collected in 2022 and 2023: Raw Data File RDF 2024-17, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 3 p
    Wolken, G.J., Wikstrom Jones, K.M., Whorton, E.N., Gould, A.I., and Hendricks, M.D., 2017, Photogrammetric data of the Haines Highway corridor: May 26, 2014: Raw Data File RDF 2017-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 20 p
    Zechmann, J.M., Daanen, R.P., Wikstrom Jones, K.M., and Wolken, G.J., 2024, Lidar-derived elevation data for Haines, Southeast Alaska, collected October 2021 and October 2022: Raw Data File RDF 2023-18, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 16 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 2025-4
  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: 13-Nov-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 Nov 13 13:27:11 2025