Bedrock 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:
Bedrock geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska
Abstract:
Preliminary Interpretive Report PIR 2001-3B, Bedrock geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, provides 1:63,360-scale geologic mapping of the Eagle A-2 Quadrangle (270 square miles; equivalent to four 7.5-minute quadrangles). The area is part of the 100-year old Fortymile mining district located in eastern Alaska near the Alaska-Yukon border. This geologic map was produced based upon results from field investigations by DGGS in 1999 and 2000, which were part of a three-year mapping program to provide geologic ground truth for airborne geophysical surveys flown by DGGS in the Fortymile mining district during 1998. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/2670.
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?
    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
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -142.009023
    East_Bounding_Coordinate: -141.000000
    North_Bounding_Coordinate: 64.253419
    South_Bounding_Coordinate: 63.996557
  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_bedrock_geology_ak_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: Alaska Division of Geological & Geophysical Surveys)
    eagle_a2_bedrock_geology_fed_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: Alaska Division of Geological & Geophysical Surveys)
    eagle_a2_bedrock_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 the 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 project's purpose was to produce a series of 1:63,360-scale geologic maps for a portion of the Fortymile mining district. The geologic data is essential 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 related to more regional geologic units. The Fortymile project is part of DGGS's Airborne Geophysical and Geological Mineral Inventory Program (AGGMI), a multi-year investment by the State of Alaska to produce framework geologic maps that 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?
    Burns, L.E. and others, 2015 (source 1 of 7)
    Burns, L.E., Geoterrex-Dighem, Stevens Exploration Management Corp., Emond, A.M., and Graham, G.R.C., 2015, Fortymile mining district electromagnetic and magnetic airborne geophysical survey data compilation: Geophysical Report GPR 2015-4, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 12 p
    Type_of_Source_Media: paper
    Source_Contribution: Geologic map compilation
    Ekberg, P.G. and others, 2021 (source 2 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
    Hendricks, M.D. and others, 2021 (source 3 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
    Szumigala, D.J. and others, 2000 (source 4 of 7)
    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
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Geologic map compilation
    Szumigala, D.J. and others, 2002 (source 5 of 7)
    Szumigala, D.J., Werdon, M.B., Newberry, R.J., Athey, J.E., Clautice, K.H., Flynn, R.L., Grady, J.C., Munly, W.C., and Johnson, M.R., 2002, Major-oxide, minor-oxide, trace-element, rare-earth element, trace geochemical, and coal quality data from rocks collected in the Eagle and Tanacross quadrangles, Alaska in 1999, 2000, 2001: Raw Data File RDF 2002-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 35 p., 1 sheet, scale 1:63,360
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    Source_Contribution: Geologic map compilation
    Werdon, M.B. and others, 2000 (source 6 of 7)
    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
    Type_of_Source_Media: paper
    Source_Scale_Denominator: 63360
    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: 2001 (process 1 of 4)
    Geologic mapping - Fieldwork for bedrock investigations, including ridge traverses, road cut investigations, and river exposures, was conducted for 350 person-days during June through August 1999 and 2000. Field notes and rock samples were collected at over 2,550 stations located throughout the quadrangle for bedrock investigations. Fifty person-days were spent on field investigations for the surficial geology. Bedrock mappers recorded observations on 1:50,000 scale topographic maps of the quadrangle. Stations were located using handheld GPS devices with location precision varying from +/-3 to 15 meters.
    Date: 2001 (process 2 of 4)
    Laboratory data compilation - Laboratory analyses were performed on rock samples collected during the fieldwork from July 1999 intermittently through April 2001. Unpublished laboratory results include petrographic work on thin sections and modal analysis of rock slabs stained for plagioclase and potassium feldspar. In addition, results from major-oxide and trace-element geochemistry of igneous and metamorphic rocks were used to calculate CIPW Norms to classify rocks according to established petrologic nomenclature.
    Date: 2001 (process 3 of 4)
    Geologic map compilation - The bedrock geologic map was compiled using field notes, analytical results from laboratory data, and all known geologic data from previous work in the quadrangle. Data was compiled on multiple layers of stable mylar at 1:50,000 scale, with some information plotted at 1:24,000 scale for more detail and later transferred to 1:50,000 scale mylar layers. Relevant information from all mylar layers was compiled onto one stable mylar sheet with abundant control points. The compilation mylar was scanned by a large-format scanner and saved as a TIFF image. The TIFF image was imported into ArcView GIS Version 3.1 and then co-registered to a georeferenced 1:63,360-scale USGS topographic base. Geologic contacts and unit polygons were digitized on-screen in ArcView. Station-specific information such as structural measurements, age samples, and location of dikes too small to be mappable features was imported into ArcView from a Microsoft Access database using GPS locations. Project staff and peer reviewers evaluated the report and accompanying data for readability and logical consistency with related information sources. Data sources used in this process:
    • Burns, L.E. and others, 2015
    • Szumigala, D.J. and others, 2000
    • Szumigala, D.J. and others, 2002
    • Werdon, M.B. and others, 2000
    Date: 2021 (process 4 of 4)
    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 then 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?
    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
    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
    Stevens, D.S.P., 2012, Engineering-geologic map of the Eagle A-1 Quadrangle, Fortymile mining district, Alaska: Preliminary Interpretive Report PIR 2002-1D, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:63,360
    Stevens, D.S.P., and Burns, P.A.C., 2010, Surficial-geologic map of the Eagle A-1 Quadrangle, Fortymile mining district: Preliminary Interpretive Report PIR 2002-1C, 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., Athey, J.E., Flynn, R.L., and Clautice, K.H., 2002, Bedrock geologic map of the Eagle A-1 Quadrangle, Fortymile mining district: Preliminary Interpretive Report PIR 2002-1B, 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., Athey, J.E., Stevens, D.S.P., Flynn, R.L., Clautice, K.H., and Craw, P.A., 2002, Geologic map of the Eagle A-1 Quadrangle, Fortymile mining district: Preliminary Interpretive Report PIR 2002-1A, 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., 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

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 2001-3B
  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: 26-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 Wed Aug 25 17:58:31 2021