Geologic map of Mount Chiginagak volcano, Alaska

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What does this data set describe?

Title: Geologic map of Mount Chiginagak volcano, Alaska
Abstract:
Mount Chiginagak is a hydrothermally active volcano on the Alaska Peninsula, approximately 170 km south-southwest of King Salmon, Alaska. This small stratovolcano, approximately 8 km in diameter, has erupted through Tertiary to Permian sedimentary and igneous rocks. The eruptive products of Chiginagak volcano record a history of chiefly andesite lava flows and associated block-and-ash flows. The oldest lavas exposed are Pleistocene in age and are found everywhere around the edifice except in the northeast sector, where Holocene lava flows dominate the landscape. Holocene activity has covered the northeast flank with rubbly-topped andesite lava flows that extend as far as 4.6 km from their source vent at the summit crater. The farthest-reaching volcanic deposits are on the southeast flank, where block-and-ash-flow, pyroclastic-flow, and lahar deposits extend down valley as far as 9 km from the summit. Limited exposure of deposits of a presumed plinian eruption of middle Pleistocene age indicate at least one episode of explosive activity in Chiginagak's past. This data distribution package provides major-oxide XRF analyses of whole-rock samples and sediments rich in hydrothermally altered material from Chiginagak volcano and 40Ar/39Ar plateau ages (preferred age) for Chiginagak lavas. All files can be downloaded from the DGGS website (<http://doi.org/10.14509/29769>).
Supplemental_Information:
Appendix1_Geochemistry: Whole-rock, major-oxide XRF, and trace-element XRF and ICP-MS analyses of whole-rock samples and sediments rich in hydrothermally altered material from Chiginagak volcano (normalized to 100% without volatiles; all Fe converted to FeOT; original analytical totals given in the "Total-majors" column). Major oxides are reported as weight percent oxide, and trace elements are reported in parts per million (ppm). Also included are samples taken by J. Riehle and E. Yount (published in the Alaska Geochemical Database [Granitto and others, 2013]). Riehle and Yount samples with bold, italicized location information are those for which we have determined that the location provided in Granitto and others (2013) is incorrect (see notes in Location Description field for these samples). 
Appendix2_ArAr: 40Ar/39Ar age dating information for Chiginagak lavas.
  1. How should this data set be cited?

    Schaefer, J.R., Scott, W.E., and Layer, P.W., 2017, Geologic map of Mount Chiginagak volcano, Alaska: Report of Investigation RI 2017-10, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 32 p., 1 sheet, scale 1:25,000

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -157.103210
    East_Bounding_Coordinate: -156.846548
    North_Bounding_Coordinate: 57.185706
    South_Bounding_Coordinate: 57.072259

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 2004
    Ending_Date: 2017
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: report and digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a point data set.

    2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in decimal degrees.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is GRS 80.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257222101000025.

  7. How does the data set describe geographic features?

    ri2017_010_Appendix1_Geochemistry.xlsx
    Whole-rock, major-oxide XRF, and trace-element XRF and ICP-MS analyses of whole-rock samples and sediments rich in hydrothermally altered material from Chiginagak volcano (normalized to 100% without volatiles; all Fe converted to FeOT; original analytical totals given in the "Total-majors" column). Major oxides are reported as weight percent oxide, and trace elements are reported in parts per million (ppm). Also included are samples taken by J. Riehle and E. Yount (published in the Alaska Geochemical Database [Granitto and others, 2013]). Riehle and Yount samples with bold, italicized location information are those for which we have determined that the location provided in Granitto and others (2013) is incorrect (see notes in Location Description field for these samples). (Source: Alaska Division of Geological & Geophysical Surveys (DGGS) and Alaska Volcano Observatory.)

    ri2017_010_Appendix2_ArAr.xlsx
    40Ar/39Ar age dating information for Chiginagak lavas. (Source: Alaska Division of Geological & Geophysical Surveys (DGGS), Alaska Volcano Observatory, and Geochronology Laboratory at the University of Alaska Fairbanks.)


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?

    We thank Jessica Larsen for her helpful review and for providing expertise in geochemical data display. This work was made possible by cooperative agreements between the U.S. Geological Survey Volcano Hazards Program and the State of Alaska Division of Geological & Geophysical Surveys, including grants G16AC00054 and G16AC00165.

  3. To whom should users address questions about the data?

    Alaska Division of Geological & Geophysical Surveys
    Metadata Manager
    3354 College Road
    Fairbanks, AK 99709-3707
    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


Why was the data set created?

Geochronological and geochemical data rocks from these localities constrain the age and distribution of Mount Chiginagak lavas.


How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

    Date: 2011 (process 1 of 2)
    Field data collection - Geologic field mapping, rock sampling, and tephra stratigraphy were conducted at Chiginagak volcano during short field excursions (2-6 days each) in 2004, 2005, 2006, 2008, and 2011. Orthorectified black-and-white airphotos from 1953, and satellite imagery such as Quickbird, Worldview, and Landsat7 aided geologic contact mapping. In particular, the approximately 1-m-pixel Worldview image acquired August 8, 2008, served as the most useful basemap for post-fieldwork geographical information system (GIS) mapping.

    Date: 2011 (process 2 of 2)
    Rock sample analysis - 40Ar/39Ar age dating of lavas was conducted at the University of Alaska Fairbanks geochronology lab. Rock samples were analyzed for major and trace-element composition by the Washington State University (WSU) GeoAnalytical Laboratory

  3. What similar or related data should the user be aware of?


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

    This publication is a final report of research and has received two technical reviews as well as technical editing. Questions regarding the accuracy of the analytical values can be best answered by the originating lab.

  2. How accurate are the geographic locations?

    Sample location coordinates were obtained using handheld GPS units. Positional accuracy was not recorded.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    This data release is complete.

  5. How consistent are the relationships among the observations, including topology?

    not applicable


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 99709-3707
    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
  2. What's the catalog number I need to order this data set?

    RI 2017-10

  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: 03-Jan-2017
Metadata author:
Alaska Division of Geological & Geophysical Surveys
Attn: Simone Montayne
Metadata Manager
3354 College Road
Fairbanks, AK 99709-3707
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:


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