LA-ICP-MS uranium lead geochronologic data of zircon from igneous and meta-igneous rocks in the Chena project area, Circle, Big Delta, and Eagle quadrangles, Alaska

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Frequently anticipated questions:


What does this data set describe?

Title:
LA-ICP-MS uranium lead geochronologic data of zircon from igneous and meta-igneous rocks in the Chena project area, Circle, Big Delta, and Eagle quadrangles, Alaska
Abstract:
LA-ICP-MS uranium lead geochronologic data of zircon from igneous and meta-igneous rocks in the Chena project area, Circle, Big Delta, and Eagle quadrangles, Alaska, Raw Data File 2025-14, provides uranium-lead (U-Pb) geochronologic data from single zircon spots, analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Alaska Division of Geological & Geophysical Surveys (DGGS) staff collected zircon data from 22 igneous and meta-igneous rock samples, primarily collected during the 2023 field season, to support the Earth Mapping Resources Initiative (Earth MRI) Chena project. Two samples were analyzed to support geologic interpretation in the Mount Harper (2022) project area. Crystallization age data are organized in the age summary data table with our interpreted crystallization ages, sample location information, and sample descriptions. The zircon grain data table contains isotopic and elemental data for each zircon spot analyzed. Both tables have accompanying data dictionaries. These data and report are available from the DGGS website: http://doi.org/10.14509/31553.
Supplemental_Information:
data:    Analytical lab data and accompanying data dictionary	
sample-summary:    Summary data spreadsheet and accompanying data dictionary
  1. How might this data set be cited?
    Buchanan, J.W., Gavel, M.M., Barrera, M.L., Regan, S.P., and Newberry, R.J., 2025, LA-ICP-MS uranium lead geochronologic data of zircon from igneous and meta-igneous rocks in the Chena project area, Circle, Big Delta, and Eagle quadrangles, Alaska: Raw Data File RDF 2025-14, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 4 p.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -146.754309
    East_Bounding_Coordinate: -143.664506
    North_Bounding_Coordinate: 65.086894
    South_Bounding_Coordinate: 64.006522
  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: spreadsheet
  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 0.0000001. Longitudes are given to the nearest 0.0000001. Latitude and longitude values are specified in decimal degrees. The horizontal datum used is WGS84.
      The ellipsoid used is WGS 84.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    rdf2025-14_zircon_grain_data.csv, rdf2025-14_zircon_grain_data_data_dictionary.csv
    Analytical lab data and accompanying data dictionary (Source: DGGS)
    rdf2025-14_age_summary.csv, rdf2025-14_age_summary_data_dictionary.csv
    Summary data spreadsheet and accompanying data dictionary (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 thank the University of Arizona LaserChron Center staff for their contributions to data collection, technical discussion, and other support. The analytical work was funded by the U.S. Geological Survey's Earth Mapping Resources Initiative (Earth MRI) under cooperative agreement G23AC00372 and by the State of Alaska. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Geological Survey. Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.
  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 dataset aims to delineate the age of igneous activity to support geologic mapping efforts, tectonic interpretations, and characterization of mineralization in the Yukon-Tanana Uplands, Alaska.

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: 2023 (process 1 of 2)
    Sample collection - Alaska Division of Geological & Geophysical Surveys (DGGS) staff collected zircon data from 22 samples of igneous and meta-igneous rocks primarily collected during the 2023 field season in support of the Earth Mapping Resources Initiative (Earth MRI) Chena project. DGGS field geologists collected fresh, unweathered samples from surface outcrops and hand-dug pits that exposed fragmented bedrock, selecting them to represent the characteristic lithology or intrusive body.
    Date: 2025 (process 2 of 2)
    Analytical methods - This report includes single-grain zircon data generated by DGGS geologists at the Arizona LaserChron Center (ALC) at the University of Arizona, with direction from laboratory staff. The accompanying report provides additional detail about the methods used by the labratory.
  3. What similar or related data should the user be aware of?
    Gavel, M.M., Twelker, Evan, Wypych, Alicja, Naibert, T.J., Newberry, R.J., Szumigala, D.J., Wildland, A.D., Barrera, M.L., Biegel, J.N., Harvey, D.A., Ketcham, R.A., Muller, I.P., and Regan, S.P., 2023, Field station locations and magnetic susceptibility data for the Chena-Pogo and Mount Harper projects, Big Delta and Circle quadrangles, Alaska, collected June-September 2023: Raw Data File RDF 2023-27, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 3 p
    Moshrefzadeh, J.A., Buchanan, J.W., Naibert, T.J., Twelker, Evan, Newberry, R.J., Szumigala, D.J., Barrera, M.L., Norwood, L.P., Acosta, M.D., and Regan, S.P., 2025, Field station locations and magnetic susceptibility data collected in 2024 for the Chena and Steese projects, Yukon-Tanana Uplands, Alaska: Raw Data File RDF 2025-5, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.

    Online Links:

    Other_Citation_Details: 5 p

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

  1. How well have the observations been checked?
    The accompanying report and data tables provide a comprehensive discussion of processing methods, with errors reported in the tables where applicable. This data is being released as part of the DGGS RDF series, which includes content describing approved techniques and methods for the collection, storage, visualization, analysis, and interpretation of scientific data. While the information has been reviewed by several geologists familiar with the study area, the data and report have not undergone formal review for technical content or conformity to DGGS editorial standards. For inquiries regarding analytical values or procedures, the originating lab is the best point of contact.
  2. How accurate are the geographic locations?
    Sample location coordinates (in WGS84 datum) were collected using GPS-enabled field tablets with a typical reported accuracy of +/- 10 meters.
  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
    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? RDF 2025-14
  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: 15-Jul-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 Tue Jul 15 13:18:39 2025