a89fc175-34e7-42a8-8980-7b4b62953f46_source eng; USA utf8 dataset Simone Montayne Alaska Division of Geological & Geophysical Surveys Metadata Manager (907)451-5020 (907)451-5050 3354 College Road Fairbanks AK 99709-3707 USA dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays pointOfContact 2025-07-31 ISO 19115 Geographic Information - Metadata ISO 19115:2003/Cor.1:2006(E) Electron probe microanalyzer data collected on samples from the Chena and Steese projects, Yukon-Tanana Uplands, Alaska 2025-01-01 publication Alaska Division of Geological & Geophysical Surveys Fairbanks Alaska, United States publisher Moshrefzadeh, J.A. originator Newberry, R.J. originator https://doi.org/10.14509/31537 tableDigital Raw Data File RDF 2025-13 6 p. Electron probe microanalyzer data collected on samples from the Chena and Steese projects, Yukon-Tanana Uplands, Alaska, Raw Data File 2025-13, provides electron probe microanalyzer (EPMA) geochemical data for individual mineral phases targeted in selected rock samples collected during the 2024 field season, along with one sample each from the 2023 and 1995 field seasons. EPMA is an analytical technique in which X-rays are excited by an electron beam. When introduced to an electron beam, each element produces X-rays with characteristic wavelengths. Therefore, EPMA allows for non-destructive quantitative analysis by comparing wavelength intensities of samples to those emitted from standards of known composition. The elements analyzed are presented as weight percent (wt.%) oxide (for most samples Na2O, MgO, Al2O3, SiO2, K2O, TiO2, CaO, FeO, and MnO; for ultramafic samples Cr2O3 instead of TiO2 and NiO instead of K2O). We do not report concentrations for elements present below detection limits-for example, TiO2, MgO, and MnO in plagioclase. The lithologies selected for electron microprobe analyses presented in this report include ultramafic, amphibolite, eclogite, schist, syenite, and paragneiss. The mineral phases analyzed from these samples include feldspar, amphibole, pyroxene, olivine, spinel, mica, garnet, epidote, chlorite, ilmenite, rutile, tourmaline, serpentine, and aluminosilicates. These data and report are available from the DGGS website: http://doi.org/10.14509/31537. To advance geological research in interior Alaska, we conducted electron probe microanalyzer (EPMA) analyses to obtain detailed geochemical data from individual mineral phases within selected rock samples. These data supported five principal objectives: (1) characterizing ultramafic rocks from the Seventymile Terrane and comparing them with lithologies of uncertain origin in adjacent Earth MRI areas; (2) clarifying the metamorphic identity of eclogitic and amphibolite-like rocks within the Chatanika assemblage; (3) analyzing mineral compositions to distinguish among diverse amphibolite units; (4) estimating pressure-temperature conditions to evaluate contrasts between assemblages; and (5) resolving ambiguities surrounding mafic phases associated with the Roy Creek intrusion. Collectively, this work contributes to a broader understanding of lithologic variability, metamorphic evolution, and geochemical diversity across the Yukon-Tanana Uplands. We thank Nathan Graham for his assistance at the University of Alaska Fairbanks Advanced Instrumentation Laboratory. The DGGS Chena and Steese projects are funded by the State of Alaska and the U.S. Geological Survey's (USGS) Earth Mapping Resources Initiative (Earth MRI) program under Cooperative Agreement numbers G24AC00323 and G23AC00372. 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 USGS. Mention of trade names or commercial products does not constitute their endorsement by the USGS. completed Alaska Division of Geological & Geophysical Surveys Metadata Manager (907)451-5020 (907)451-5050 3354 College Road Fairbanks AK 99709-3707 USA dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays 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. pointOfContact notPlanned Actinolite Albite Amphibole Amphibolite Analyses Analytical Lab Results Analytical Results Augite Bedrock Bedrock Geology Biotite Chemistry Chlorite Chromite Clinopyroxene Clinozoisite DGGS Diopside Earth MRI Economic Geology Enstatite Epidote Exploration Garnet Geochemical Data Geochemical Surveys Geochemistry Geologic Geology Hornblende Ilmenite Intrusive K-Feldspar Kyanite Lab Methods Magnetite Major Oxides Metamorphic Metamorphic Grade Metamorphic Minerals Metamorphic Rocks Metamorphism Methods Mineral Resources Minerals Mining Muscovite Olivine Omphacite Paragonite Petrographic Petrology Plagioclase Quartz Resource Assessment Resource Information Resources Rocks Rutile Serpentine Sillimanite Spinel Titanite Tourmaline Tremolite Ultramafic theme Alaska Division of Geological & Geophysical Surveys Alder Creek Bedrock Creek Boulder Creek Captain Creek Chatanika Circle Mining District Cleary Creek Cora Creek Cottonwood Creek Dome Creek Dora Creek Fairbanks Mining District Gulch Creek Last Chance Creek Lost Creek Lulu Creek Munson Creek Newsboy Mine Olympia Creek Paldo Creek Richardson Mining District Rosa Creek Ruby Creek Salcha River Serpentine Creek Sheep Creek Sorrels Creek Tolovana Mining District Vault Creek Williams Creek Willow Creek Yukon-Tanana Upland place Alaska Division of Geological & Geophysical Surveys Chatanika Terrane Fortymile River Assemblage Lake George Assemblage Seventymile Terrane stratum Alaska Division of Geological & Geophysical Surveys 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. otherRestrictions 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. otherRestrictions 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). Geochemical data from samples collected in 2023 for the Chena and Mount Harper projects, Big Delta, Circle, Fairbanks, and Eagle quadrangles, Alaska 2025-01-01 publication Alaska Division of Geological & Geophysical Surveys Fairbanks Alaska, United States publisher 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. originator https://doi.org/10.14509/31123 Raw Data File RDF 2024-2 5 p crossReference Field station locations and magnetic susceptibility data collected in 2024 for the Chena and Steese projects, Yukon-Tanana Uplands, Alaska 2025-01-01 publication Alaska Division of Geological & Geophysical Surveys Fairbanks Alaska, United States publisher 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. originator https://doi.org/10.14509/31476 Raw Data File RDF 2025-5 5 p crossReference Preliminary geologic map of the Fairbanks mining district, Alaska 1996-01-01 publication Alaska Division of Geological & Geophysical Surveys Fairbanks Alaska, United States publisher Newberry, R.J. originator Bundtzen, T.K. originator Clautice, K.H. originator Combellick, R.A. originator Douglas, Tom originator Laird, G.M. originator Liss, S.A. originator Pinney, D.S. originator Reifenstuhl, R.R. originator Solie, D.N. originator https://doi.org/10.14509/1740 Public Data File PDF 96-16 17 p., 2 sheets, scale 1:63,360 crossReference Metamorphism of the Ladue River-Mount Fairplay area 2021-01-01 publication Alaska Division of Geological & Geophysical Surveys Fairbanks Alaska, United States publisher Newberry, R.J. originator Twelker, Evan originator https://doi.org/10.14509/30736 Report of Investigation RI 2021-5B p. 33-39 crossReference Bedrock geologic map of the Richardson Mining District, Big Delta Quadrangle, Alaska 2025-01-01 publication Alaska Division of Geological & Geophysical Surveys Fairbanks Alaska, United States publisher Twelker, Evan originator Newberry, R.J. originator Naibert, T.J. originator Wypych, Alicja originator https://doi.org/10.14509/31649 Preliminary Interpretive Report PIR 2025-2A 1 sheet, scale 1:100,000 crossReference vector eng; USA geoscientificInformation -147.658324 -143.842385 64.361696 65.484846 2023-01-01 2025-01-01 >data: Analytical lab data and accompanying data dictionary >sample-summary: Summary data spreadsheet and accompanying data dictionary true spreadsheet unknown Alaska Division of Geological & Geophysical Surveys Metadata Manager (907)451-5020 (907)451-5050 3354 College Road Fairbanks AK 99709-3707 USA dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays 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. distributor Contact DGGS for current pricing Free download https://doi.org/10.14509/31537 spreadsheet table information dataset Horizontal Positional Accuracy Report Location data for field stations were collected using GPS-enabled tablets or smartphones running the ESRI Field Maps app. The devices have reported errors between 10 and 12 m. Latitude and longitude are reported in the WGS84 datum. This data release is complete. This data release is complete. Not applicable This lineage was generated by the FGDC CSDGM to 19139 transformation Sample collection - DGGS geologists collected rock samples furing the 2024 field season while conducting 1:100,000-scale bedrock geologic mapping of a 9,635 km2 (~3,720 mi2) area of the Yukon-Tanana Uplands of eastern Interior Alaska 2024-01-01T00:00:00 Analytical methods - DGGS staff used an electron probe microanalyzer (EPMA) to analyze individual mineral phases in selected rock samples from the 2024 field season, along with one sample each from 2023 and 1995. Their selections for electron microprobe analysis included ultramafic, amphibolite, eclogite, schist, syenite, and paragneiss lithologies. They targeted mineral phases such as feldspar, amphibole, pyroxene, olivine, spinel, mica, garnet, epidote, chlorite, ilmenite, rutile, tourmaline, serpentine, and aluminosilicates. They reported elemental concentrations as weight percent oxides-typically Na2O, MgO, Al2O3, SiO2, K2O, TiO2, CaO, FeO, and MnO, with Cr2O3 and NiO replacing TiO2 and K2O in ultramafic samples. 2025-01-01T00:00:00 otherRestrictions 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. unknown This metadata was automatically generated from the FGDC Content Standard for Digital Geospatial Metadata standard (version FGDC-STD-001-1998) using the 2019-08-12T11:11:00 version of the FGDC CSDGM to ISO 19139 transform. Simone Montayne Alaska Division of Geological & Geophysical Surveys Metadata Manager (907)451-5020 (907)451-5050 3354 College Road Fairbanks AK 99709-3707 USA dggspubs@alaska.gov 8 am to 4:30 pm, Monday through Friday, except State holidays pointOfContact