Identification_Information: Citation: Citation_Information: Originator: Buchanan, J.W. Originator: Barrera, M.L. Originator: Gavel, M.M. Originator: Truskowski, C.M. Originator: Wildland, A.D. Originator: Moshrefzadeh, J.A. Originator: Regan, S.P. Publication_Date: 2026 Title: LA-ICP-MS uranium-lead detrital zircon data from metamorphic and sedimentary rocks from the Yukon-Tanana Upland, Alaska Geospatial_Data_Presentation_Form: spreadsheet Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2026-13 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 5 p. Online_Linkage: https://doi.org/10.14509/32080 Description: Abstract: LA-ICP-MS uranium-lead detrital zircon data from metamorphic and sedimentary rocks from the Yukon-Tanana Upland, Alaska, Raw Data File 2026-13, presents uranium-lead (U-Pb) geochronologic data from single zircon spots analyzed by laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). U-Pb isotopic zircon data were collected from 42 metamorphic and sedimentary rock samples. Division of Geological & Geophysical Survey (DGGS) geologists collected the samples during the 2022, 2023, and 2024 field seasons, in support of the United States Geological Survey's Earth Mapping Resources Initiative (USGS Earth MRI). This report contains samples from the Steese, Chena, and Mount Harper (2024, 2023, and 2022, respectively) geologic mapping projects within the Livengood, Circle, Charley River, Fairbanks, Big Delta, and Eagle quadrangles. These Earth MRI projects are part of a broader effort to modernize geologic mapping of the nation's surface and subsurface with a focus on collecting data in areas of potential critical mineral resources. The USGS selected the Yukon-Tanana Upland (YTU) as the most likely area for new potential mineral resources in Alaska, and it has been the primary focus area of the DGGS Mineral Resources Section since 2019. Geologic mapping was completed across the roughly 34,500 km2 area with new helicopter- and vehicle-supported fieldwork and the compilation of existing DGGS, USGS, industry, and academic datasets. The goal of this geochronologic dataset is to delineate the depositional timeframe and provenance of metamorphic and sedimentary rock packages and, where possible, to define the timing of metamorphism, thereby supporting future geologic mapping and elucidating the tectonic history of the YTU. These data and accompanying discussion are released as a DGGS Raw Data File, and all publication components are available from the DGGS website at: http://doi.org/10.14509/32080. Purpose: The purpose of this dataset is to provide U-Pb zircon geochronologic information that constrains the depositional age, provenance, and metamorphic history of metamorphic and sedimentary rock units in the Yukon-Tanana Upland. These data support DGGS and USGS Earth MRI geologic mapping efforts by supplying age constraints from 42 samples collected during recent field seasons, enabling improved interpretation of regional tectonic evolution and refinement of geologic map units across multiple quadrangles. Supplemental_Information: >ytu_dz_zircon_grain_data: Analytical lab data and accompanying data dictionary >ytu_dz_zircon_summary_data: Summary data spreadsheet and accompanying data dictionary Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2022 Ending_Date: 2026 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -147.662245 East_Bounding_Coordinate: -142.758433 North_Bounding_Coordinate: 65.162614 South_Bounding_Coordinate: 63.897066 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Theme_Keyword: Age Dates Theme_Keyword: Analyses Theme_Keyword: Analyses and Sampling Theme_Keyword: Analytical Lab Results Theme_Keyword: Analytical Results Theme_Keyword: Bedrock Theme_Keyword: Bedrock Geology Theme_Keyword: Biotite Theme_Keyword: Detrital Zircon Theme_Keyword: DGGS Theme_Keyword: Earth MRI Theme_Keyword: Exploration Theme_Keyword: Garnet Theme_Keyword: Geochronology Theme_Keyword: Geologic Theme_Keyword: Geological Process Theme_Keyword: Geology Theme_Keyword: Granite Theme_Keyword: Greenschist Theme_Keyword: Hornfels Theme_Keyword: Isotopes Theme_Keyword: Lab Methods Theme_Keyword: Lead Theme_Keyword: Lithology Theme_Keyword: Metamorphic Theme_Keyword: Metamorphic Deposits Theme_Keyword: Metamorphic Minerals Theme_Keyword: Metamorphic Rocks Theme_Keyword: Metamorphism Theme_Keyword: Metasedimentary Rocks Theme_Keyword: Metavolcanic rocks Theme_Keyword: Methods Theme_Keyword: Mineral Assessment Theme_Keyword: Mineral Exploration Theme_Keyword: Mineral Resources Theme_Keyword: Minerals Theme_Keyword: Mining Theme_Keyword: Muscovite Theme_Keyword: Phyllite Theme_Keyword: Provenance Theme_Keyword: Quartz Theme_Keyword: Quartzite Theme_Keyword: Resource Assessment Theme_Keyword: Resources Theme_Keyword: Rocks Theme_Keyword: Sample Location Theme_Keyword: Sandstone Theme_Keyword: Schist Theme_Keyword: Sedimentary Theme_Keyword: U-Pb Theme_Keyword: U-Pb Zircon Theme_Keyword: Uranium Theme_Keyword: Zircon Place: Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Place_Keyword: Anderson Creek Place_Keyword: Beaver Creek Place_Keyword: Beckman Creek Place_Keyword: Boulder Creek Place_Keyword: Circle Mining District Place_Keyword: Delta River Mining District Place_Keyword: Dome Creek Place_Keyword: Emory Creek Place_Keyword: Fairbanks Mining District Place_Keyword: Fortymile Mining District Place_Keyword: Gold Creek Place_Keyword: Goodpaster Mining District Place_Keyword: Joseph Creek Place_Keyword: Lost Creek Place_Keyword: Marten Creek Place_Keyword: Molly Creek Place_Keyword: Moose Creek Place_Keyword: Munson Creek Place_Keyword: Norvell Creek Place_Keyword: Olnes Place_Keyword: Pine Creek Place_Keyword: Salcha River Place_Keyword: Slate Creek Place_Keyword: Stuart Creek Place_Keyword: Tanana River Place_Keyword: Teuchet Creek Stratum: Stratum_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Stratum_Keyword: Fairbanks-Chena Assemblage Stratum_Keyword: Fortymile River Assemblage Stratum_Keyword: Klondike Assemblage Stratum_Keyword: Lake George Assemblage Stratum_Keyword: Nasina Assemblage 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. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: 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. Data_Set_Credit: The authors thank the University of Arizona LaserChron Center staff for their contributions to data collection, technical discussions, and other support. The analytical work was funded by the U.S. Geological Survey's Earth Mapping Resources Initiative (Earth MRI) under cooperative agreements G22AC00288, G23AC00372, and G24AC00323 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. Cross_Reference: Citation_Information: Originator: Buchanan, J.W. Publication_Date: 2026 Title: Geochemical reanalysis of archival igneous rock pulp samples, Yukon-Tanana Upland, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2026-16 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 4 p Online_Linkage: https://doi.org/10.14509/32120 Cross_Reference: Citation_Information: Originator: Buchanan, J.W. Originator: Barrera, M.L. Originator: Newberry, R.J. Publication_Date: 2026 Title: LA-ICP-MS uranium-lead zircon data from igneous rocks collected during the 2025 field season from the Steese-White Mountains and Chena project areas, Yukon-Tanana Upland, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2026-11 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 4 p Online_Linkage: https://doi.org/10.14509/32064 Cross_Reference: Citation_Information: Originator: Buchanan, J.W. Originator: Barrera, M.L. Originator: Moshrefzadeh, J.A. Originator: Truskowski, C.M. Originator: Newberry, R.J. Publication_Date: 2025 Title: LA-ICP-MS uranium-lead zircon data from samples in the Chena and Steese project areas Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2025-25 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 4 p Online_Linkage: https://doi.org/10.14509/31731 Cross_Reference: Citation_Information: Originator: Buchanan, J.W. Originator: Gavel, M.M. Originator: Barrera, M.L. Originator: Regan, S.P. Originator: Newberry, R.J. Publication_Date: 2025 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 Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2025-14 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 4 p Online_Linkage: https://doi.org/10.14509/31553 Cross_Reference: Citation_Information: Originator: Buchanan, J.W. Originator: Gavel, M.M. Originator: Wildland, A.D. Originator: Newberry, R.J. Publication_Date: 2025 Title: LA-ICP-MS uranium lead geochronologic data of zircon from igneous and meta-igneous rocks in the Mount Harper project area, Eagle, Tanacross, Mount Hayes, and Big Delta quadrangles, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2025-4 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 5 p Online_Linkage: https://doi.org/10.14509/31552 Cross_Reference: Citation_Information: Originator: Buchanan, J.W. Originator: Wypych, Alicja Originator: Barrera, M.L. Originator: Biegel, J.M. Originator: Gavel, M.M. Originator: Harvey, D.A. Originator: Ketcham, R.A. Originator: Muller, I.P. Originator: Naibert, T.J. Originator: Newberry, R.J. Originator: Regan, S.P. Originator: Szumigala, D.J. Originator: Twelker, Evan Originator: Wildland, A.D. Publication_Date: 2025 Title: Geochemical data from samples collected in 2023 for the Chena and Mount Harper projects, Big Delta, Circle, Fairbanks, and Eagle quadrangles, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2024-2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 5 p Online_Linkage: https://doi.org/10.14509/31123 Cross_Reference: Citation_Information: Originator: Gavel, M.M. Originator: Regan, S.P. Originator: Holland, Mark Originator: Wildland, A.D. Originator: Wypych, Alicja Originator: Naibert, T.J. Originator: Twelker, Evan Publication_Date: 2023 Title: U-Pb zircon geochronology of bedrock samples collected in the Eagle and Tanacross quadrangles, eastern Alaska Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2023-2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 38 p Online_Linkage: https://doi.org/10.14509/31013 Cross_Reference: Citation_Information: Originator: Gavel, M.M. Originator: Twelker, Evan Originator: Wypych, Alicja Originator: Naibert, T.J. Originator: Newberry, R.J. Originator: Szumigala, D.J. Originator: Wildland, A.D. Originator: Barrera, M.L. Originator: Biegel, J.N. Originator: Harvey, D.A. Originator: Ketcham, R.A. Originator: Muller, I.P. Originator: Regan, S.P. Publication_Date: 2023 Title: 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 Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2023-27 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 3 p Online_Linkage: https://doi.org/10.14509/31096 Cross_Reference: Citation_Information: Originator: Moshrefzadeh, J.A. Originator: Newberry, R.J. Publication_Date: 2025 Title: Electron probe microanalyzer data collected on samples from the Chena and Steese projects, Yukon-Tanana Uplands, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2025-13 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 6 p Online_Linkage: https://doi.org/10.14509/31537 Cross_Reference: Citation_Information: Originator: Moshrefzadeh, J.A. Originator: Barrera, M.L. Originator: Buchanan, J.W. Originator: Naibert, T.J. Originator: Newberry, R.J. Originator: Norwood, L.P. Originator: Regan, S.P. Originator: Szumigala, D.J. Originator: Twelker, Evan Originator: Walser, S.L. Originator: Wilson, K.R. Publication_Date: 2025 Title: Field station locations and magnetic susceptibility data collected in 2025 for the Steese project, Yukon-Tanana Uplands, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2025-28 v. 2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 3 p Online_Linkage: https://doi.org/10.14509/31736 Cross_Reference: Citation_Information: Originator: Moshrefzadeh, J.A. Originator: Buchanan, J.W. Originator: Naibert, T.J. Originator: Twelker, Evan Originator: Newberry, R.J. Originator: Szumigala, D.J. Originator: Barrera, M.L. Originator: Norwood, L.P. Originator: Acosta, M.D. Originator: Regan, S.P. Publication_Date: 2025 Title: Field station locations and magnetic susceptibility data collected in 2024 for the Chena and Steese projects, Yukon-Tanana Uplands, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2025-5 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 5 p Online_Linkage: https://doi.org/10.14509/31476 Cross_Reference: Citation_Information: Originator: Moshrefzadeh, J.A. Originator: Naibert, T.J. Originator: Hofmann, Florian Originator: Newberry, R.J. Originator: Twelker, Evan Originator: Buchanan, J.W. Publication_Date: 2026 Title: 40Ar/39Ar geochronology data from the Big Delta and Circle quadrangles, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2026-14 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 55 p Online_Linkage: https://doi.org/10.14509/32086 Cross_Reference: Citation_Information: Originator: Moshrefzadeh, Jamshid Originator: Acosta, M.D. Originator: Barrera, M.L. Originator: Buchanan, J.W. Originator: Naibert, T.J. Originator: Newberry, R.J. Originator: Norwood, L.P. Originator: Regan, S.P. Originator: Szumigala, D.J. Originator: Twelker, Evan Publication_Date: 2025 Title: Geochemical data from samples collected in 2024 for the Chena and Steese projects, Big Delta, Circle, Fairbanks, and Livengood quadrangles, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2025-17 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 3 p Online_Linkage: https://doi.org/10.14509/31692 Cross_Reference: Citation_Information: Originator: Naibert, T.J. Originator: Heizler, M.T. Originator: Newberry, R.J. Originator: Twelker, Evan Originator: Wypych, Alicja Publication_Date: 2023 Title: 40Ar/39Ar geochronology data from the Tanacross and Eagle quadrangles, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2023-23 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 19 p Online_Linkage: https://doi.org/10.14509/31085 Cross_Reference: Citation_Information: Originator: Naibert, T.J. Originator: Wypych, Alicja Originator: Newberry, R.J. Originator: Twelker, Evan Originator: Gavel, M.M. Originator: Wildland, A.D. Originator: Barrera, M.L. Originator: Avirett, D.F. Originator: Muller, I.P. Originator: Blackwell, N.J. Originator: Szumigala, D.J. Publication_Date: 2024 Title: Bedrock geologic map of the Taylor Mountain area, Eagle and Tanacross quadrangles, Alaska Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2024-6B Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 1 sheet, scale 1:100,000 Online_Linkage: https://doi.org/10.14509/31168 Cross_Reference: Citation_Information: Originator: Newberry, R.J. Originator: Moshrefzadeh, J.A. Publication_Date: 2026 Title: Interior Alaska amphibolite mineral compositions: A key to distinguishing metamorphic assemblage Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2026-2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 33 p Online_Linkage: https://doi.org/10.14509/32081 Cross_Reference: Citation_Information: Originator: Truskowski, C.M. Originator: Heizler, M.T. Originator: Naibert, T.J. Originator: Newberry, R.J. Originator: Twelker, Evan Originator: Szumigala, D.J. Publication_Date: 2025 Title: 40Ar/39Ar geochronology data from the Big Delta, Eagle, and Mount Hayes quadrangles, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2025-11 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 21 p Online_Linkage: https://doi.org/10.14509/31534 Cross_Reference: Citation_Information: Originator: Twelker, Evan Publication_Date: 2026 Title: Geologic investigation of the Chena-Pogo area, interior Alaska Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2026-3 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 1 p Online_Linkage: https://doi.org/10.14509/32111 Cross_Reference: Citation_Information: Originator: Twelker, Evan Originator: Newberry, R.J. Originator: Naibert, T.J. Originator: Wypych, Alicja Originator: Gavel, M.M. Originator: Barrera, M.L. Originator: Szumigala, D.J. Originator: Truskowski, C.M. Originator: Muller, I.P. Originator: Fessenden, S.N. Originator: Blackwell, N.J. Originator: Harvey, D.A. Originator: Wildland, A.D. Publication_Date: 2025 Title: Bedrock geologic maps of the Mount Harper-Middle Fork area, Volkmar River-Healy River area, Goodpaster River-Shaw Creek area, and the Richardson Mining District, Alaska Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2025-2 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 38 p Online_Linkage: https://doi.org/10.14509/31648 Cross_Reference: Citation_Information: Originator: Wypych, Alicja Originator: Gavel, M.M. Originator: Naibert, T.J. Originator: Avirett, D.F. Originator: Barrera, M.L. Originator: Hubbard, A.K. Originator: Newberry, R.J. Originator: Regan, S.P. Originator: Twelker, Evan Originator: Wildland, A.D. Originator: Wyatt, W.C. Publication_Date: 2022 Title: Geochemical data from samples collected in 2021 for the Taylor Mountain project, Tanacross and Eagle quadrangles, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2022-4 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 3 p Online_Linkage: https://doi.org/10.14509/30843 Cross_Reference: Citation_Information: Originator: Wypych, Alicja Originator: Twelker, Evan Originator: Naibert, T.J. Originator: Gavel, M.M. Originator: Newberry, R.J. Originator: Szumigala, D.J. Originator: Wildland, A.D. Originator: Barrera, M.L. Originator: Harvey, D.A. Originator: Muller, I.P. Originator: Fessenden, S.N. Originator: Blackwell, N.J. Publication_Date: 2023 Title: Geochemical data from samples collected in 2022 for the Mount Harper geologic mapping project, Big Delta, Mount Hayes, and Eagle quadrangles, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2023-24 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 3 p Online_Linkage: https://doi.org/10.14509/31089 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: This publication is a DGGS Raw Data File (RDF). Reports in the RDF series present field data and analytical results with limited or no interpretation by DGGS staff or project collaborators. The report and accompanying data have been evaluated by project staff for general readability and logical consistency but have not undergone technical peer review. Information presented in this release is subject to change. Logical_Consistency_Report: Not applicable Completeness_Report: This data release is complete. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Location data for samples were recorded in the WGS84 datum using GPS-enabled field tablets and provided here in the NAD83 datum. Sample location coordinates have a typical reported accuracy of about 10 meters. Lineage: Process_Step: Process_Description: Sample collection - Fresh, unweathered rock samples were collected from surface outcrops by DGGS field geologists during geologic mapping in the Big Delta and Circle quadrangles. Location data for samples were recorded in the WGS84 datum using GPS-enabled field tablets. Samples were selected for age dating based on terrane, map unit, and the presence of viable mineral phases suitable for 40Ar/39Ar analysis. Each sample was examined as a hand specimen under a binocular microscope and as a thin section under a petrographic microscope to identify unaltered mineral phases and confirm suitability for geochronologic analysis. Process_Date: 2024 Process_Step: Process_Description: Sample preparation - To generate single-grain zircon data, DGGS geologists worked at the Arizona LaserChron Center (ALC) at the University of Arizona under the direction of laboratory staff. Whole-rock samples were sent to the ALC, where they were cleaned and processed through a jaw crusher and roller mill. Zircon grains were isolated using magnetic separation and gravimetric separation with methylene iodide (MI). "Soft" minerals, those that are highly damaged, fractured, altered, or are otherwise less resistant, were removed using a Wig-L-Bug amalgamator, if necessary. Pyrite and apatite were removed by acid wash before hand-picking of zircon grains, if necessary. Heavy mineral grains (~2500) from a portion of the isolated mineral separate for each sample were poured onto double-sided tape and then mounted into 1-inch-diameter epoxy pucks, with one sample per puck. Process_Date: 2024 Process_Step: Process_Description: Sample analysis - Back-scatter electron, cathodoluminescence, and transmitted light images were collected for each sample, and some zircon grains were analyzed in multiple areas to examine complex internal textures. The analysis_number field identifies each analysis by sample name, grain number, and zircon morphology. LA-ICP-MS data were collected using an Element2 HR mass spectrometer, and zircon grains were ablated with a Teledyne/Photon Machines Analyte G2 excimer laser equipped with HelEx. Most samples included about 315 zircon spot analyses using 15 to 20 micron diameter spots, except where fewer grains were available. Spots were cleaned with rapid-burst laser shots using 40 micron diameters before isotopic data collection, and ablated material was carried in helium to the plasma source. Isotopes measured included 204Pb, 206Pb, 207Pb, 208Pb, 232Th, 235U, and 238U. Standards FC-1, SL-2, and R33 were analyzed between unknowns to monitor instrument drift. Data reduction followed published methods and was performed at ALC using the MATLAB-based program AgeCalcML. Raw data were corrected for common Pb, backgrounds, and isobaric interference, and isotopic ratios were compared to reference values to determine fractionation factors. Internal uncertainties were propagated following established procedures. Process_Date: 2024 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.0000001 Longitude_Resolution: 0.0000001 Geographic_Coordinate_Units: decimal degrees Geodetic_Model: Horizontal_Datum_Name: NAD83 Ellipsoid_Name: GRS 80 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257222101 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: rdf2026-13-ytu_dz_zircon_grain_data.csv, rdf2026-13-ytu_dz_zircon_grain_data_dictionary.csv Entity_Type_Definition: Analytical lab data and accompanying data dictionary Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: ytu_dz_zircon_grain_data Detailed_Description: Entity_Type: Entity_Type_Label: rdf2026-13-ytu_dz_zircon_summary_data.csv, rdf2026-13-ytu_dz_zircon_summary_data_dictionary.csv Entity_Type_Definition: Summary data spreadsheet and accompanying data dictionary Entity_Type_Definition_Source: DGGS Entity_Attribute_Layer_Name: ytu_dz_zircon_summary_data Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: 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. Resource_Description: RDF 2026-13 Distribution_Liability: 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. Standard_Order_Process: Non-digital_Form: DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount. Fees: Contact DGGS for current pricing Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: spreadsheet Format_Version_Date: 20260707 Format_Information_Content: table Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://doi.org/10.14509/32080 Fees: Free download Metadata_Reference_Information: Metadata_Date: 20260707 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Person: Simone Montayne Contact_Position: Metadata Manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Use_Constraints: If the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the Alaska Department of Natural Resources or Division of Geological & Geophysical Surveys. Metadata_Extensions: Online_Linkage: https://dggs.alaska.gov/metadata/dggs.ext Profile_Name: dggs metadata extensions