Identification_Information:
  Citation:
    Citation_Information:
      Originator: Herriott, T.M.
      Originator: Crowley, J.L.
      Originator: LePain, D.L.
      Originator: Wartes, M.A.
      Originator: Harun, N.T.
      Originator: Schmitz, M.D.
      Publication_Date: 2024
      Title: Zircon geochronology of Torok and Nanushuk Formations sandstones at Slope Mountain and a Seabee Formation tephra deposit at Ninuluk Bluff, central North Slope, Alaska
      Geospatial_Data_Presentation_Form: csv
      Series_Information:
        Series_Name: Raw Data File
        Issue_Identification: RDF 2024-33
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 22 p.
      Online_Linkage: https://doi.org/10.14509/31152
  Description:
    Abstract: Zircon geochronology of Torok and Nanushuk Formations sandstones at Slope Mountain and a Seabee Formation tephra deposit at Ninuluk Bluff, central North Slope, Alaska, Raw Data File 2024-33, presents LA-ICPMS and CA-ID-TIMS U-Pb data for five DZ samples collected from a well-known exposure at Slope Mountain, which is one of the few localities where the transition between mid-Cretaceous Torok and Nanushuk Formations is preserved in outcrop. We also report new U-Pb tephra zircon data from basal Seabee Formation at Ninuluk Bluff, a key-and similarly rare-site where the transition between Late Cretaceous Nanushuk strata and overlying Seabee crops out. These tandem-dated samples were collected during summer field seasons in 2018 and 2019 as part of DGGS's North Slope and Brooks Range foothills basin analysis program. The new zircon geochronology results from Slope Mountain and Ninuluk Bluff are documented and permanently archived herein. These data and report are available from the DGGS website: http://doi.org/10.14509/31152.
    Purpose: Resolving the ages of Alaska's stratigraphic units is foundational to understanding sedimentary basin evolution and thier hydrocarbon potential. Existing stratal age constraints in Alaska often remain tied to paleontologic assessments completed during mid-twentieth century geologic mapping campaigns led by the U.S. Geological Survey. Although many of these relative-age frameworks reflect extensive fossil collections, the provinciality and wide or ambiguous age ranges for some faunas and floras, especially at high latitudes, can present notable hurdles to further understanding of basin histories. U-Pb geochronology of zircon is starting to refine, or redefine, the chronostratigraphic frameworks in Alaska basins.
    Supplemental_Information:
      >LAICPMS:    LA-ICPMS (Laser Ablation Inductively Coupled Plasma Mass Spectrometry) zircon U-Pb results and accompanying data dictionary	
      >CAIDTIMS:    CA-ID-TIMS (chemical abrasion-isotope dilution-thermal ionization mass spectrometry) zircon U-Pb results and accompanying data dictionary	
      >SummaryAges:    Summary ages and accompanying data dictionary	
      >MachineRead:    Key analytical data optimized for database ingestion and accompanying data dictionary
  Time_Period_of_Content:
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date: 2018
        Ending_Date: 2024
    Currentness_Reference: ground condition
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: None planned
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: -153.288220
      East_Bounding_Coordinate: -149.025180
      North_Bounding_Coordinate: 69.126390
      South_Bounding_Coordinate: 68.727560
  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: Basins
      Theme_Keyword: Bedrock
      Theme_Keyword: Brookian
      Theme_Keyword: Deltaic Facies
      Theme_Keyword: Detrital Zircon
      Theme_Keyword: Formations
      Theme_Keyword: Geochronology
      Theme_Keyword: Geologic
      Theme_Keyword: Geology
      Theme_Keyword: Hydrocarbon
      Theme_Keyword: Igneous
      Theme_Keyword: Isotopes
      Theme_Keyword: Lab Methods
      Theme_Keyword: Marine
      Theme_Keyword: Marine Sedimentation
      Theme_Keyword: Marine Transgressions
      Theme_Keyword: Methods
      Theme_Keyword: Mudstone
      Theme_Keyword: Resources
      Theme_Keyword: Rocks
      Theme_Keyword: Sandstone
      Theme_Keyword: Sediment
      Theme_Keyword: Sedimentary
      Theme_Keyword: Sedimentation
      Theme_Keyword: Sedimentology
      Theme_Keyword: Stratigraphy
      Theme_Keyword: Tephra
      Theme_Keyword: Transgression
      Theme_Keyword: Transgressive
      Theme_Keyword: Tuff
      Theme_Keyword: U-Pb
      Theme_Keyword: Zircon
      Theme_Keyword: Zircon U-Pb
    Place:
      Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys
      Place_Keyword: Colville Basin
      Place_Keyword: Colville River
      Place_Keyword: Ninuluk Bluff
      Place_Keyword: Ninuluk Creek
      Place_Keyword: North Slope
      Place_Keyword: Siksikpak Ridge
      Place_Keyword: Slope Mountain
    Stratum:
      Stratum_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys
      Stratum_Keyword: Nanushuk Formation
      Stratum_Keyword: Seabee Formation
      Stratum_Keyword: Torok Formation
    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: Albian
      Temporal_Keyword: Cenomanian
      Temporal_Keyword: Cretaceous
      Temporal_Keyword: Mesozoic
  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: Our base camp for several recent field seasons was at Toolik Field Station, which is placed on and surrounded by 'the ancestral hunting grounds of the Nunamiut, and occasional hunting grounds and routes of the Gwich'in, Koyukuk, and Inupiaq peoples' (www.uaf.edu/toolik/about/land-acknowledgement.php); these surrounding lands include Slope Mountain and some of the earliest known Alaska Native peoples sites in northern Alaska. We thank Arctic Slope Regional Corporation for granting access to their lands at Ninuluk Bluff, with Erik Kenning processing our permit requests. Our chronostratigraphic work in northern Alaska has benefited from discussions with Richard Lease, Peter Flaig, Joshua Long, Robert Gillis, Jared Gooley, David Houseknecht, Amanda Willingham, and Mareca Guthrie. Amanda Willingham and Michelle Gavel participated in our Slope Mountain fieldwork during 2018. Robin Carbaugh digitized laser ablation spot locations and labels on the cathodoluminescence imagery of appendix B and joined us on several traverses at Slope Mountain and Ninuluk Bluff. We thank Toolik Field Station and Happy Valley staff and managers for hosting our field crews. Tom Rat Ratledge and Sarah Rafaelli safely transported personnel during fieldwork. Kristen Janssen and Simone Montayne provided publication support. Reviews by Robert Gillis and an anonymous referee improved this data report. The State of Alaska funded this study, and funding for the analytical infrastructure of the Boise State University Isotope Geology Laboratory is provided by the National Science Foundation (grants EAR-0521221, EAR-0824974, EAR-1337887, EAR-1735889).
  Cross_Reference:
    Citation_Information:
      Originator: Harris, E.E.
      Originator: Mull, C.G.
      Originator: Reifenstuhl, R.R.
      Originator: Montayne, Simone
      Publication_Date: 2002
      Title: Geologic map of the Dalton Highway (Atigun Gorge to Slope Mountain) area, southern Arctic Foothills, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2002-2
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 1 sheet, scale 1:63,360
      Online_Linkage: https://doi.org/10.14509/2867
  Cross_Reference:
    Citation_Information:
      Originator: LePain, D.L.
      Originator: McCarthy, P.J.
      Originator: Kirkham, R.A.
      Publication_Date: 2009
      Title: Sedimentology and sequence stratigraphy of the middle Albian-Cenomanian Nanushuk Formation in outcrop, central North Slope, Alaska
      Series_Information:
        Series_Name: Report of Investigation
        Issue_Identification: RI 2009-1 v. 2
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 76 p., 1 sheet
      Online_Linkage: https://doi.org/10.14509/19761
  Cross_Reference:
    Citation_Information:
      Originator: LePain, D.L.
      Originator: Kirkham, R.A.
      Publication_Date: 2024
      Title: Measured stratigraphic section, upper Nanushuk Formation (Cenomanian), Ninuluk Bluff, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2024-3
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 28 p., 1 sheet
      Online_Linkage: https://doi.org/10.14509/31150
  Cross_Reference:
    Citation_Information:
      Originator: LePain, D.L.
      Originator: Wartes, M.A.
      Originator: Kirkham, R.A.
      Originator: Mongrain, J.R.
      Publication_Date: 2021
      Title: Measured stratigraphic section in the upper Schrader Bluff Formation (Late Campanian-Maastrichtian?), Ivishak River, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2021-3
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 11 p., 1 sheet
      Online_Linkage: https://doi.org/10.14509/30693
  Cross_Reference:
    Citation_Information:
      Originator: Willingham, A.L.
      Originator: Herriott, T.M.
      Publication_Date: 2020
      Title: Photogrammetry-derived digital surface model and orthoimagery of Slope Mountain, North Slope, Alaska, June 2018
      Series_Information:
        Series_Name: Raw Data File
        Issue_Identification: RDF 2020-1
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 9 p
      Online_Linkage: https://doi.org/10.14509/30419
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report: The accompanying report and data tables provide a comprehensive discussion of processing methods. When applicable, errors are reported in the data tables. These data are being released in the DGGS Raw Data File series. Reports in this series present field data and analytical results with limited or no interpretation by DGGS staff or project collaborators. Analytical results may include interpretations by laboratories when an interpretive review of the analytical findings is necessary to develop usable output. The reports and accompanying data have been evaluated by project staff for general readability and logical consistency but have not undergone technical peer review.
  Logical_Consistency_Report: Not applicable
  Completeness_Report: This data release is complete.
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report: We recorded location information using GPS-enabled tablets running Esri ArcGIS Field Maps app, with a reported horizontal error of approximately 5 to 10 meters. Latitude and longitude are reported in the WGS84 coordinate system.
  Lineage:
    Process_Step:
      Process_Description: Sample collection and analysis - Detrital zircon samples were collected from marine sandstone beds of the Torok and Nanushuk Formations, using typical field sampling protocols and taking great care to avoid contamination. Four of the DZ samples of this study are from the lower 296 m of the LePain and others (2022) section, and one additional DZ sample (18TMH112A) is from Nanushuk Formation at the top of the Slope Mountain stratigraphy. The tephra zircon sample was collected from a volcanic air-fall deposit in Seabee Formation at Ninuluk Bluff, taking similar care to avoid contamination.
      Process_Date: 2019
    Process_Step:
      Process_Description: Analytical methods - Zircon from the Slope Mountain DZ samples and the Ninuluk Bluff tephra zircon sample were separated and analyzed by U-Pb geochronology at the Boise State University Isotope Geology Laboratory. All samples were analyzed first by LA-ICPMS, delineating the overall character of date distributions for the DZ samples and distinguishing approximately syn-eruptive versus clearly xenocrystic or otherwise older zircon for the tephra sample. The DZ samples were principally analyzed to establish MDAs, with LA-ICPMS serving as a moderate-precision screening tool to target youthful, near-stratal-age zircon for high-precision follow-up analysis by CA-ID-TIMS. All mid-Cretaceous DZ identified by LA-ICPMS were plucked from their epoxy mounts and analyzed by CA-ID-TIMS; in several cases, "a" and "b" zircon fragments from the same crystal were analyzed by CA-ID-TIMS to further evaluate reproducibly and accuracy of the results (see Herriott and others [2019a] for additional discussion of these protocols). A sub-set (n=6) of tephra zircon from the Ninuluk Bluff sample that yielded mid-Cretaceous LA-ICPMS dates were plucked for analyses by CA-ID-TIMS. Appendix A of the accompanying report provides detailed analytical methods for the LA-ICPMS and CA-ID-TIMS experiments. Appendix B of the accompanying report presents cathodoluminescence images of zircon analyzed during this study, including annotations with LA-ICPMS analysis numbers, laser ablation spot locations, z-grain (CA-ID-TIMS) designations, and dates and analytical uncertainties (2 sigma) for the CA-ID-TIMS results.
      Process_Date: 2023
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: WGS84
      Ellipsoid_Name: WGS 84
      Semi-major_Axis: 6378137
      Denominator_of_Flattening_Ratio: 298.257223563
Entity_and_Attribute_Information:
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: rdf2024-33_DataFile1_LAICPMS.zip
      Entity_Type_Definition: LA-ICPMS (Laser Ablation Inductively Coupled Plasma Mass Spectrometry) zircon U-Pb results and accompanying data dictionary
      Entity_Type_Definition_Source: DGGS
      Entity_Attribute_Layer_Name: LAICPMS
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: rdf2024-33_DataFile2_CAIDTIMS.zip
      Entity_Type_Definition: CA-ID-TIMS (chemical abrasion-isotope dilution-thermal ionization mass spectrometry) zircon U-Pb results and accompanying data dictionary
      Entity_Type_Definition_Source: DGGS
      Entity_Attribute_Layer_Name: CAIDTIMS
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: rdf2024-33_DataFile3_SummaryAges.zip
      Entity_Type_Definition: Summary ages and accompanying data dictionary
      Entity_Type_Definition_Source: DGGS
      Entity_Attribute_Layer_Name: SummaryAges
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: rdf2024-33_DataFile4_MachineRead.zip
      Entity_Type_Definition: Key analytical data optimized for database ingestion and accompanying data dictionary
      Entity_Type_Definition_Source: DGGS
      Entity_Attribute_Layer_Name: MachineRead
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 2024-33
  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.
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  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: csv
        Format_Version_Date: 20250106
        Format_Information_Content: table
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: https://doi.org/10.14509/31152
    Fees: Free download
Metadata_Reference_Information:
  Metadata_Date: 20250106
  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