Surficial-geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska

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Frequently anticipated questions:

What does this data set describe?

Title:
Surficial-geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska
Abstract:
Surficial-geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska, Report of Investigation 2004-1C, illustrates the distribution of unconsolidated deposits and undifferentiated bedrcok units in the Salcha River-Pogo area. It was prepared by interpretation of 1:63,360-scale false-color infrared aerial photographs taken July 1978, July 1979, and August 1981, and is locally verified by ground observations during field visits. Based on the generally subdued nature of glacial deposits in the field area, we speculate that undifferentiated glacial deposits mapped are composed of material deposited by the Charley River (early? Pleistocene), Mt. Harper (middle? Pleistocene), and Eagle (early? Wisconsin) glaciations (Weber, 1986). It is highly unlikely that the area was glaciated during Salcha (late Wisconsin) or Ramshorn (Holocene) glaciations. The northeast-southwest-trending Shaw Creek fault crosses the study area. Although the fault was observed on 1:63,360-scale, false-color, infrared aerial photographs, we were unable to document offset on surficial geologic units. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/18001.
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?
    Reger, R.D., Burns, P.A.C., and Staft, L.A., 2008, Surficial-geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska: Report of Investigation RI 2004-1C, 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: -145.520318
    East_Bounding_Coordinate: -144.720459
    North_Bounding_Coordinate: 64.755898
    South_Bounding_Coordinate: 64.368211
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1997
    Ending_Date: 2023
    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: 6
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -147
      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?
    salcha_river_pogo_surficial_ak_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: DGGS)
    salcha_river_pogo_surficial_gems_db_pkg
    Geodatabase, layer files, style files, and fonts (Source: DGGS)
    salcha_river_pogo_surficial_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?
    This map is a component 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 02HQPA0003. The geologic map database was converted to GeMS, quality controlled, and then finalized by DGGS staff Wes Buchanan and Mike Hendricks. 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?

This map shows the distribution of unconsolidated deposits and undifferentiated bedrock units in the Salcha River-Pogo area.

How was the data set created?

  1. From what previous works were the data drawn?
    Ekberg, P.G. and others, 2021 (source 1 of 3)
    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 3)
    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
    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: 2002 (process 1 of 2)
    Geologic mapping - Fieldwork for surficial investigations, including traverses and river exposures, was conducted during the summer of 2001 and 2002. Field notes and sediment samples were collected throughout the map area for surficial investigations. Surficial mapping involved using Pewe and others (1967), and Weber (1983, 1986) on a regular basis for checking glacial geology and general units.Surficial mappers recorded observations on 1:63,360 scale (approximate) color-infrared aerial photographs and 1:63,360 scale topographic base maps. Stations located using air photos and handheld GPS devices with location precision varying from +/-3 to 15 meters. Surficial geologic map was compiled using field notes from fieldwork process step (above) and all known geologic data from previous work in quadrangle.The main sources of existing data include Bacon and others (1996), Pewe and others (1967), and Weber (1983, 1987). Geologic map contacts were delineated by photointerpretation of 1:63,360-scale color-infrared aerial photographs onto clear acetate overlays. The contacts were transferred from the overlays onto USGS 1:63,360 topographic base maps using a zoom transfer scope, the maps were scanned and georeferenced, and the contacts were then digitized using ArcMap. Polygon topology was established and unit designations assigned in ArcMap. DGGS-standard symbology was applied to polygons, linework, and annotation in ArcMap, and the graphics files were converted into .eps files for export to Adobe Illustrator for final cartographic assembly. 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?
    Reger, R.D., and Pewe, T.L., 2002, Geologic map of the Big Delta A-4 Quadrangle, Alaska: Report of Investigation RI 2002-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 1 sheet, scale 1:63,360
    Reger, R.D., and Pewe, T.L., 2002, Geologic map of the Big Delta A-4 Quadrangle, Alaska: Report of Investigation RI 2002-2, 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 Burns, L.E., 2001, Reconnaissance bedrock geology of the Pogo area, Big Delta B-2 and B-3 quadrangles, Alaska: Preliminary Interpretive Report PIR 2001-5, 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?
    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 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)
    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? RI 2004-1C
  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: 19-Apr-2023
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 Apr 19 13:55:10 2023