Buchanan, J.W.Barrera, M.L.Gavel, M.M.Truskowski, C.M.Wildland, A.D.Moshrefzadeh, J.A.Regan, S.P.2026spreadsheetRaw Data FileRDF 2026-13Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys5 p.https://doi.org/10.14509/32080LA-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.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.>ytu_dz_zircon_grain_data: Analytical lab data and accompanying data dictionary >ytu_dz_zircon_summary_data: Summary data spreadsheet and accompanying data dictionary20222026ground conditionCompleteNone planned-147.662245-142.75843365.16261463.897066ISO 19115 Topic CategorygeoscientificInformationAlaska Division of Geological & Geophysical SurveysAge DatesAnalysesAnalyses and SamplingAnalytical Lab ResultsAnalytical ResultsBedrockBedrock GeologyBiotiteDetrital ZirconDGGSEarth MRIExplorationGarnetGeochronologyGeologicGeological ProcessGeologyGraniteGreenschistHornfelsIsotopesLab MethodsLeadLithologyMetamorphicMetamorphic DepositsMetamorphic MineralsMetamorphic RocksMetamorphismMetasedimentary RocksMetavolcanic rocksMethodsMineral AssessmentMineral ExplorationMineral ResourcesMineralsMiningMuscovitePhylliteProvenanceQuartzQuartziteResource AssessmentResourcesRocksSample LocationSandstoneSchistSedimentaryU-PbU-Pb ZirconUraniumZirconAlaska Division of Geological & Geophysical SurveysAnderson CreekBeaver CreekBeckman CreekBoulder CreekCircle Mining DistrictDelta River Mining DistrictDome CreekEmory CreekFairbanks Mining DistrictFortymile Mining DistrictGold CreekGoodpaster Mining DistrictJoseph CreekLost CreekMarten CreekMolly CreekMoose CreekMunson CreekNorvell CreekOlnesPine CreekSalcha RiverSlate CreekStuart CreekTanana RiverTeuchet CreekAlaska Division of Geological & Geophysical SurveysFairbanks-Chena AssemblageFortymile River AssemblageKlondike AssemblageLake George AssemblageNasina AssemblageThis 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).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.Alaska Division of Geological & Geophysical SurveysMetadata Managermailing and physical

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FairbanksAK99709-3707USA(907)451-5020(907)451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysPlease 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.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.Buchanan, J.W.2026Raw Data FileRDF 2026-16Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys4 phttps://doi.org/10.14509/32120Buchanan, J.W.Barrera, M.L.Newberry, R.J.2026Raw Data FileRDF 2026-11Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys4 phttps://doi.org/10.14509/32064Buchanan, J.W.Barrera, M.L.Moshrefzadeh, J.A.Truskowski, C.M.Newberry, R.J.2025Raw Data FileRDF 2025-25Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys4 phttps://doi.org/10.14509/31731Buchanan, J.W.Gavel, M.M.Barrera, M.L.Regan, S.P.Newberry, R.J.2025Raw Data FileRDF 2025-14Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys4 phttps://doi.org/10.14509/31553Buchanan, J.W.Gavel, M.M.Wildland, A.D.Newberry, R.J.2025Raw Data FileRDF 2025-4Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys5 phttps://doi.org/10.14509/31552Buchanan, J.W.Wypych, AlicjaBarrera, M.L.Biegel, J.M.Gavel, M.M.Harvey, D.A.Ketcham, R.A.Muller, I.P.Naibert, T.J.Newberry, R.J.Regan, S.P.Szumigala, D.J.Twelker, EvanWildland, A.D.2025Raw Data FileRDF 2024-2Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys5 phttps://doi.org/10.14509/31123Gavel, M.M.Regan, S.P.Holland, MarkWildland, A.D.Wypych, AlicjaNaibert, T.J.Twelker, Evan2023Preliminary Interpretive ReportPIR 2023-2Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys38 phttps://doi.org/10.14509/31013Gavel, M.M.Twelker, EvanWypych, AlicjaNaibert, 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.Regan, S.P.2023Raw Data FileRDF 2023-27Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys3 phttps://doi.org/10.14509/31096Moshrefzadeh, J.A.Newberry, R.J.2025Raw Data FileRDF 2025-13Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys6 phttps://doi.org/10.14509/31537Moshrefzadeh, J.A.Barrera, M.L.Buchanan, J.W.Naibert, T.J.Newberry, R.J.Norwood, L.P.Regan, S.P.Szumigala, D.J.Twelker, EvanWalser, S.L.Wilson, K.R.2025Raw Data FileRDF 2025-28 v. 2Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys3 phttps://doi.org/10.14509/31736Moshrefzadeh, J.A.Buchanan, J.W.Naibert, T.J.Twelker, EvanNewberry, R.J.Szumigala, D.J.Barrera, M.L.Norwood, L.P.Acosta, M.D.Regan, S.P.2025Raw Data FileRDF 2025-5Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys5 phttps://doi.org/10.14509/31476Moshrefzadeh, J.A.Naibert, T.J.Hofmann, FlorianNewberry, R.J.Twelker, EvanBuchanan, J.W.2026Raw Data FileRDF 2026-14Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys55 phttps://doi.org/10.14509/32086Moshrefzadeh, JamshidAcosta, M.D.Barrera, M.L.Buchanan, J.W.Naibert, T.J.Newberry, R.J.Norwood, L.P.Regan, S.P.Szumigala, D.J.Twelker, Evan2025Raw Data FileRDF 2025-17Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys3 phttps://doi.org/10.14509/31692Naibert, T.J.Heizler, M.T.Newberry, R.J.Twelker, EvanWypych, Alicja2023Raw Data FileRDF 2023-23Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys19 phttps://doi.org/10.14509/31085Naibert, T.J.Wypych, AlicjaNewberry, R.J.Twelker, EvanGavel, M.M.Wildland, A.D.Barrera, M.L.Avirett, D.F.Muller, I.P.Blackwell, N.J.Szumigala, D.J.2024Preliminary Interpretive ReportPIR 2024-6BFairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys1 sheet, scale 1:100,000https://doi.org/10.14509/31168Newberry, R.J.Moshrefzadeh, J.A.2026Preliminary Interpretive ReportPIR 2026-2Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys33 phttps://doi.org/10.14509/32081Truskowski, C.M.Heizler, M.T.Naibert, T.J.Newberry, R.J.Twelker, EvanSzumigala, D.J.2025Raw Data FileRDF 2025-11Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys21 phttps://doi.org/10.14509/31534Twelker, Evan2026Preliminary Interpretive ReportPIR 2026-3Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys1 phttps://doi.org/10.14509/32111Twelker, EvanNewberry, R.J.Naibert, T.J.Wypych, AlicjaGavel, M.M.Barrera, M.L.Szumigala, D.J.Truskowski, C.M.Muller, I.P.Fessenden, S.N.Blackwell, N.J.Harvey, D.A.Wildland, A.D.2025Preliminary Interpretive ReportPIR 2025-2Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys38 phttps://doi.org/10.14509/31648Wypych, AlicjaGavel, M.M.Naibert, T.J.Avirett, D.F.Barrera, M.L.Hubbard, A.K.Newberry, R.J.Regan, S.P.Twelker, EvanWildland, A.D.Wyatt, W.C.2022Raw Data FileRDF 2022-4Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys3 phttps://doi.org/10.14509/30843Wypych, AlicjaTwelker, EvanNaibert, T.J.Gavel, M.M.Newberry, R.J.Szumigala, D.J.Wildland, A.D.Barrera, M.L.Harvey, D.A.Muller, I.P.Fessenden, S.N.Blackwell, N.J.2023Raw Data FileRDF 2023-24Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys3 phttps://doi.org/10.14509/31089This 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.Not applicableThis data release is complete.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.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.2024Sample 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.2024Sample 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.2024point0.00000010.0000001decimal degreesNAD83GRS 806378137298.257222101rdf2026-13-ytu_dz_zircon_grain_data.csv, rdf2026-13-ytu_dz_zircon_grain_data_dictionary.csvAnalytical lab data and accompanying data dictionaryDGGSytu_dz_zircon_grain_datardf2026-13-ytu_dz_zircon_summary_data.csv, rdf2026-13-ytu_dz_zircon_summary_data_dictionary.csvSummary data spreadsheet and accompanying data dictionaryDGGSytu_dz_zircon_summary_dataAlaska Division of Geological & Geophysical SurveysMetadata Managermailing and physical

3354 College Road

FairbanksAK99709-3707USA(907)451-5020(907)451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysPlease 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.RDF 2026-13The 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.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.Contact DGGS for current pricingspreadsheet20260707tablehttps://doi.org/10.14509/32080Free download20260707Alaska Division of Geological & Geophysical SurveysSimone MontayneMetadata Managermailing and physical

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FairbanksAK99709-3707USA(907)451-5020(907)451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysFGDC Content Standard for Digital Geospatial MetadataFGDC-STD-001-1998If 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.https://dggs.alaska.gov/metadata/dggs.extdggs metadata extensions