Identification_Information: Citation: Citation_Information: Originator: Wypych, Alicja Originator: Jones, J.V., III Originator: O'Sullivan, Paul Publication_Date: 2020 Title: U-Pb Zircon ages from bedrock samples collected in the Tanacross D-1, and parts of the D-2, C-1, and C-2 quadrangles, Alaska Geospatial_Data_Presentation_Form: report and digital data Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2020-2 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/10.14509/30465 Description: Abstract: This Alaska Division of Geological & Geophysical Surveys (DGGS) Preliminary Interpretive Report presents U-Pb ages of zircons from 14 sedimentary, metamorphic, and igneous samples collected during 2017 and 2018 field investigations in the northeastern Tanacross Quadrangle, Alaska. The DGGS Northeast Tanacross project is a part of multi-year effort to investigate the geology and mineral-resource potential of the Yukon-Tanana Uplands region in collaboration with the U.S. Geological Survey. The purpose of the U-Pb isotopic study is to better understand the Devonian-to-Mississippian and Mesozoic-to-Early Paleogene episodes of magmatic and tectonic events within the Yukon-Tanana Uplands and the relationship of magmatism to the metallic mineral deposits. This area is characterized by the presence of two Late Devonian to Mississippian metamorphic assemblages--Lake George and Fortymile River. Both assemblages are composed of metasedimentary and metavolcanic rocks that have been intruded by Devonian to Eocene intrusive rocks of varying composition and texture. Paleozoic intrusive rocks are deformed and metamorphosed and include prevalent Late Devonian-Early Mississippian augen orthogneiss, herein called the Divide Mountain suite, that was emplaced into and deformed together with the Lake George assemblage. The Fortymile River assemblage is primarily cross cut by Mississippian to Permian intrusive rocks that are also pervasively deformed and metamorphosed. Following Jurassic to mid-Cretaceous regional metamorphism and deformation, all metamorphic rock packages were intruded by Mid- to Late-Cretaceous volcanic and plutonic rocks, some of which have known or suspected potential for gold together with silver, zinc, copper, and lead mineralization. Products included in this data release are: A summary of sample-collection methods, the laboratory report, analytical data tables, and associated metadata. All components of this data release are available on the DGGS website: http://doi.org/10.14509/30465. Purpose: The DGGS Northeast Tanacross project is a part of multi-year effort to investigate the geology and mineral-resource potential of the Yukon-Tanana Uplands region in collaboration with the U.S. Geological Survey. The purpose of the U-Pb isotopic study is to better understand the Devonian-to-Mississippian and Mesozoic-to-Early Paleogene episodes of magmatic and tectonic events within the Yukon-Tanana Uplands and the relationship of magmatism to the metallic mineral deposits. Supplemental_Information: >geochron-data: Spreadsheets with geochronology lab results, preferred age summary, and data dictionary. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2017 Ending_Date: 2018 Currentness_Reference: ground condition Status: Progress: complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -141.649124 East_Bounding_Coordinate: -141.011909 North_Bounding_Coordinate: 63.985334 South_Bounding_Coordinate: 63.621316 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys 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: Chemistry Theme_Keyword: Conglomerate Theme_Keyword: Geochronology Theme_Keyword: Geological Process Theme_Keyword: Geology Theme_Keyword: Granite Theme_Keyword: Granodiorite Theme_Keyword: Igneous Theme_Keyword: Igneous Rocks Theme_Keyword: Isotopes Theme_Keyword: Metamorphic Theme_Keyword: Metamorphic Rocks Theme_Keyword: Metasedimentary Rocks Theme_Keyword: Metavolcanic rocks Theme_Keyword: Methods Theme_Keyword: Mineral Assessment Theme_Keyword: Mineral Composition Theme_Keyword: Mineral Development Theme_Keyword: Mineral Exploration Theme_Keyword: Mineral Resources Theme_Keyword: Mineralogy Theme_Keyword: Minerals Theme_Keyword: Plutonic Theme_Keyword: Plutons Theme_Keyword: Rock Units Theme_Keyword: Rocks Theme_Keyword: STATEMAP Project Theme_Keyword: Sedimentary Rocks Theme_Keyword: Tectonics Theme_Keyword: U-Pb Theme_Keyword: Zircon Place: Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Place_Keyword: Dewey Creek Place_Keyword: Divide Mountain Place_Keyword: Dude Creek Place_Keyword: Fishhook Bend Place_Keyword: Fortymile Mining District Place_Keyword: Gold Bar Creek Place_Keyword: Liberty Creek Place_Keyword: McCord Creek Place_Keyword: McElfish Creek Place_Keyword: Sixtymile River Place_Keyword: Yukon-Tanana Upland Stratum: Stratum_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Stratum_Keyword: Fortymile River Assemblage Stratum_Keyword: Lake George Assemblage Temporal: Temporal_Keyword_Thesaurus: Walker, J.D., Geissman, J.W., Bowring, S.A, and Babcock, L.E., comp., 2012, Geologic Time Scale v. 4.0: Geological Society of America Temporal_Keyword: Cretaceous Temporal_Keyword: Devonian Temporal_Keyword: Jurassic Temporal_Keyword: Mississippian Temporal_Keyword: Permian Temporal_Keyword: Triassic 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 Data_Set_Credit: The Northeast Tanacross project was funded by Alaska State General Funds and U.S Geological Survey STATEMAP Award No. G18AC00137. The authors would like to thank Dr. Sean Regan for providing insightful review comments for this PIR. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government. Cross_Reference: Citation_Information: Originator: Naibert, T.J. Originator: Benowitz, J.A. Originator: Wypych, Alicja Originator: Sicard, K.R. Originator: Twelker, Evan Publication_Date: 2018 Title: 40Ar/39Ar data from the Tanacross D-1 and D-2, Big Delta B-4 and B-5, and Mount Hayes A-6 quadrangles, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2018-3 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 15 p Online_Linkage: http://doi.org/10.14509/30112 Cross_Reference: Citation_Information: Originator: Todd, Erin Originator: Wypych, Alicja Originator: Kylander-Clark, Andrew Publication_Date: 2019 Title: U-Pb and Lu-Hf isotope, age, and trace element data from zircon separates from the Tanacross D-1, and parts of D-2, C-1, and C-2 quadrangles Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2019-5 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 10 p Online_Linkage: http://doi.org/10.14509/30198 Cross_Reference: Citation_Information: Originator: Wypych, Alicja Originator: Hubbard, T.D. Originator: Naibert, T.J. Originator: Athey, J.E. Originator: Newberry, R.J. Originator: Sicard, K.R. Originator: Twelker, Evan Originator: Werdon, M.B. Originator: Willingham, A.L. Originator: Wyatt, W.C. Originator: Lockett, A.C. Publication_Date: 2019 Title: Northeastern Tanacross geologic map, Tanacross D-1, D-2, C-1, and C-2 quadrangles, Alaska Series_Information: Series_Name: Preliminary Interpretive Report Issue_Identification: PIR 2019-6 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 20 p., 1 sheet, scale 1:63,360 Online_Linkage: http://doi.org/10.14509/30197 Cross_Reference: Citation_Information: Originator: Wypych, Alicja Originator: Naibert, T.J. Originator: Athey, J.E. Originator: Newberry, R.J. Originator: Sicard, K.R. Originator: Twelker, Evan Originator: Werdon, M.B. Originator: Willingham, A.L. Originator: Wyatt, W.C. Publication_Date: 2018 Title: Major-oxide and trace-element geochemical data from rocks collected in 2018 for the Northeast Tanacross project, Tanacross C-1, C-2, D-1, and D-2 quadrangles, Alaska Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2018-4 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 4 p Online_Linkage: http://doi.org/10.14509/30113 Cross_Reference: Citation_Information: Originator: Wypych, Alicja Originator: Twelker, Evan Originator: Athey, J.E. Originator: Hubbard, T.D. Originator: Naibert, T.J. Originator: Newberry, R.J. Originator: Sicard, K.R. Originator: Werdon, M.B. Originator: Willingham, A.L. Originator: Wyatt, W.C. Publication_Date: 2018 Title: New geologic investigations of northeast Tanacross (presentation): Alaska Miners Association Annual Convention, Anchorage, Alaska, November 4-10, 2018 Series_Information: Series_Name: Poster and Presentation Issue_Identification: Wypych, Alicja and others, 2018 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 37 p Online_Linkage: http://doi.org/10.14509/30123 Cross_Reference: Citation_Information: Originator: Wypych, Alicja Originator: Twelker, Evan Originator: Athey, J.E. Originator: Lockett, A.C. Originator: Naibert, T.J. Originator: Sicard, K.R. Originator: Werdon, M.B. Originator: Willingham, A.L. Publication_Date: 2017 Title: Major-oxide and trace-element geochemical data from rocks collected in the Tanacross C-1, D-1, and D-2 quadrangles, Alaska in 2017 Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2017-10 Publication_Information: Publication_Place: Fairbanks, Alaska, United States Publisher: Alaska Division of Geological & Geophysical Surveys Other_Citation_Details: 4 p Online_Linkage: http://doi.org/10.14509/29778 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: These data are being released in the DGGS Preliminary Interpretive Report series. This publication series is meant to allow rapid release of field observations or initial interpretations of geology or analytical data. It has undergone limited peer review but does not necessarily conform to DGGS editorial standards. Interpretations or conclusions contained in this publication are subject to change. Logical_Consistency_Report: not applicable Completeness_Report: This data release is complete. Requests for additional information regarding the parameters and definitions of the analytical values should be directed to the originating lab. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Sample-location coordinates (in WGS84 datum) were collected using handheld Trimble Juno T5 GPS units, with typical reported accuracy of about 10 meters. Location coordinates for all dated samples are provided in an accompanying .csv file in decimal-degree format, WGS84 datum. Lineage: Process_Step: Process_Description: Sample selection - Fresh, unweathered samples from surface bedrock outcrops were collected by DGGS field geologists; samples of representative rock types and important intrusive bodies were prioritized for analysis. Rocks were collected in summer 2017 and 2018. Petrographic thin sections of each rock were examined to determine suitability for U-Pb geochronologic analysis. In some cases, samples from several closely adjacent outcrops were combined to create a composite sample of sufficient volume for analysis. Process_Date: 2018 Process_Step: Process_Description: Sample preparation and data analysis - Zircon grains from rock samples were analyzed to obtain U-Pb isotopic geochronologic ages using the methods described in the accompanying report. Process_Date: 2018 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.0001 Longitude_Resolution: 0.0001 Geographic_Coordinate_Units: decimal degrees Geodetic_Model: Horizontal_Datum_Name: World Geodetic System of 1984 Ellipsoid_Name: WGS 84 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257223563000025 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Attribute_Layer_Name: geochron-data Entity_Type_Label: pir2002-2-geochron-data.zip, pir2020-02-geochron-summary.csv, and pir2020-02-data-dictionary.csv Entity_Type_Definition: Spreadsheets with geochronology lab results, preferred age summary, and data dictionary. Entity_Type_Definition_Source: U-Pb geochronology analyses were performed by Paul O'Sullivan of GeoSep Services 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 Resource_Description: PIR 2020-2 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: ASCII tabular files Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://doi.org/10.14509/30465 Fees: Free download Metadata_Reference_Information: Metadata_Date: 20200831 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Person: Simone Montayne 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 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://www.dggs.alaska.gov/metadata/dggs.ext Profile_Name: dggs metadata extensions