Surficial-geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska

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Frequently anticipated questions:


What does this data set describe?

Title:
Surficial-geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska
Abstract:
Preliminary Interpretive Report 2001-3C, Surficial-Geologic Map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska, provides 1:63,360-scale geologic mapping of the Eagle A-2 Quadrangle. The area is part of the 100-year old Fortymile mining district and is located in eastern Alaska near the Alaska-Yukon border. This map illustrates the distribution of a variety of unconsolidated deposits and undifferentiated bedrock in the Eagle A-2 Quadrangle, Fortymile mining district. It was prepared by the interpretation of 1:63,360-scale, false-color, infrared aerial photographs taken from July 1978 through August 1981 and is locally verified by ground observations during field visits. The results should be considered reconnaissance in nature. The dominant unconsolidated deposit is colluvium, which mantles most surfaces other than the tops of ridges and those areas immediately adjacent to streams. Three levels of stream terrace can be traced along major drainages at elevations of roughly 200, 100, and 30 meters above modern streams. A fourth low terrace is limited to the southwest part of the map area. Pleistocene mammalian remains have been recovered from ice-rich organic silt and muck overlying placer gravels in many valleys. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/2671.
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?
    Pinney, D.S., 2001, Surficial-geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2001-3C, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:63,360
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -142.009023
    East_Bounding_Coordinate: -141.495528
    North_Bounding_Coordinate: 64.252564
    South_Bounding_Coordinate: 63.997419
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1999
    Ending_Date: 2001
    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 NAD27.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.40000000037.
      The flattening of the ellipsoid used is 1/294.978698199999997.
  7. How does the data set describe geographic features?
    eagle_a2_surficial_geology_ak_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: Alaska Division of Geological & Geophysical Surveys)
    eagle_a2_surficial_geology_fed_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: Alaska Division of Geological & Geophysical Surveys)
    eagle_a2_surficial_geology_fed_gems_shapefile_pkg
    Shapefiles and open data files (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?
    This project is part of the Alaska Airborne Geophysical/Geological Mineral Inventory Program funded by the Alaska State Legislature and managed by State of Alaska, Department of Natural Resources (DNR), Division of Geological & Geophysical Surveys (DGGS). Partial funding for the geologic mapping was also provided by the U.S. Geological Survey, National Cooperative Geologic Mapping Program, under STATEMAP award number 00HQAG0071 under the NCGM STATEMAP program for FY2000. 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 the project was to produce a series of 1:63,360-scale geologic maps for a portion of the Fortymile mining district. The geologic data is important for characterizing and distinguishing between geologic units. Previously published 1:63,360-scale geologic maps of this area have been reconnaissance-level maps or only covered portions of the quadrangle. Mapping at 1:63,360 scale or greater detail is needed to identify critical geologic features that may relate to more regional geologic units. The Fortymile project is part of DGGS's Airborne Geophysical and Geological Mineral Inventory Program (AGGMI), a special multi-year investment by the State of Alaska to produce framework geologic maps that will expand the knowledge base of Alaska's geologic and mineral resources, catalyze future private-sector mineral exploration and development, and guide government agencies' planning.

How was the data set created?

  1. From what previous works were the data drawn?
    Ekberg, P.G. and others, 2021 (source 1 of 4)
    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
    Hendricks, M.D. and others, 2021 (source 2 of 4)
    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
    Weber, F.R. and Hamilton, T.D., 1984, p. 42-48 (source 3 of 4)
    Weber, F.R., and Hamilton, T.D., 1984, Glacial geology of the Mt. Prindle area, Yukon-Tanana upland, Alaska: Professional Report PR 86H, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: p. 42-48
    Type_of_Source_Media: paper
    Source_Contribution: Geologic mapping
    Yeend, W.E., 1996 (source 4 of 4)
    Yeend, W.E., 1996, Gold placers of the historical Fortymile River region, Alaska: Bulletin B 2125, U.S. Geological Survey, United States.

    Online Links:

    Other_Citation_Details: 75 p., 1 sheet, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Geologic mapping
  2. How were the data generated, processed, and modified?
    Date: 2001 (process 1 of 3)
    Geologic mapping - Fieldwork for surficial investigations, including traverses, roadcut investigations, and river exposures, was conducted for 60 person-days during June through August in 1999 - 2000. Field notes and sediment samples were collected throughout the quadrangle for surficial investigations. Surficial mapping involved using Yeend (1996) regularly for checking placer geology and general units. Surficial mappers recorded observations on co-registered acetate overlays on 1:50,000-scale (nominal) color-infrared aerial photographs and directly on 1:63,360-scale topographic base maps. Stations were located using air photos and handheld GPS devices with location precision varying from 3 to 15 meters. Laboratory analyses were performed on radiocarbon samples and gold-bearing gravel samples from June 1999 intermittently through April 2001. Data sources used in this process:
    • Weber, F.R. and Hamilton, T.D., 1984, p. 42-48
    • Yeend, W.E., 1996
    Date: 2001 (process 2 of 3)
    Geologic map compilation - Surficial-geologic information was interpreted using 1:50,000-scale (nominal) air-photo stereopairs, and compiled onto acetate overlays. The overlay information was transferred to a paper 1:63,360-scale USGS topographic base using a zoom transfer scope. Surficial-geologic information was digitized from the paper USGS topographic base map into Arc/Info 7.0.4 GIS (ArcEdit module) using a large-format digitizing table. Surficial-geologic polygons and lines were then edited and attributed using Arc, Info, and ArcEdit. Bedrock point data (see DGGS PIR 2002-1B) of locations of structural observations (strike, dip, cleavage, jointing, etc.) and 'rubblecrop' were intersected with the surficial-geologic polygon coverage using the Arc command 'intersect' in order to identify locations that were mapped as surficial materials based on aerial photography but were found to have small exposures that were desirable to be mapped as bedrock. These areas were then modified in the surficial-geologic coverages to be areas of bedrock exposure. Project staff and peer reviewers evaluated the report and accompanying data for readability and logical consistency with related information sources.
    Date: 2021 (process 3 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:
    • Ekberg, P.G. and others, 2021
    • Hendricks, M.D. and others, 2021
  3. What similar or related data should the user be aware of?
    Staff, DGGS, and Szumigala, D.J., 2000, Alaska GeoSurvey News - Mineral-oriented geologic mapping of the Fortymile mining district: Newsletter NL 2000-3, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 9 p
    Pinney, D.S., 2001, Engineering - geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2001-3D, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:63,360
    Szumigala, D.J., Newberry, R.J., Werdon, M.B., Finseth, B.A., Pinney, D.S., and Flynn, R.L., 2000, Major-oxide, minor-oxide, trace-element, and geochemical data from rocks collected in a portion of the Fortymile mining district, Alaska, 1999: Raw Data File RDF 2000-1 v. 1.0.1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 24 p., 2 sheets, scale 1:63,360
    Werdon, M.B., Newberry, R.J., Szumigala, D.J., and Pinney, D.S., 2001, Geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2001-3A, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:63,360
    Werdon, M.B., Newberry, R.J., and Szumigala, D.J., 2001, Bedrock geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2001-3B, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:63,360
    Werdon, M.B., Szumigala, D.J., Newberry, R.J., Grady, J.C., and Munly, W.C., 2000, Major-oxide, minor-oxide, trace-element, rare-earth element, and geochemical data from rocks collected in Eagle and Tanacross quadrangles, Alaska in 2000: Raw Data File RDF 2000-4, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 29 p., 3 sheets, scale 1:63,360

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-dependent. 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 Preliminary Interpretive Report (PIR). A PIR is intended to provide timely release maps and reports with a preliminary interpretation of geology or analytical data. One or two people familiar with the geologic problem have reviewed this publication for technical content.
  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? PIR 2001-3C
  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: 25-Aug-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 Tue Aug 24 16:39:53 2021