Identification_Information:
  Citation:
    Citation_Information:
      Originator: Solie, D.N.
      Originator: Layer, P.W.
      Originator: Werdon, M.B.
      Originator: Newberry, R.J.
      Originator: Freeman, L.K.
      Originator: Lessard, R.R.
      Publication_Date: 2013
      Title: 40Ar/39Ar data, Alaska Highway corridor from Delta Junction to Canada border, parts of Mount Hayes, Tanacross, and Nabesna quadrangles, Alaska
      Geospatial_Data_Presentation_Form: report, digital-data
      Series_Information:
        Series_Name: Raw Data File
        Issue_Identification: RDF 2013-8
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 35 p.
      Online_Linkage: http://dx.doi.org/10.14509/26841
  Description:
    Abstract: 40Ar/39Ar analyses of igneous rocks from the Alaska Highway corridor between Delta Junction and the Canada border show a range of Cretaceous ages from about 68 Ma to about 112 Ma. The 25 samples fall into two broad age groups. The younger group ranges from about 68 Ma to 73 Ma; the older group ranges from a minimum age of about 84 Ma to about 103 Ma. One sample, a mafic dike, yielded an older age of about 112 Ma.
    Purpose: Alaska Division of Geological & Geophysical Surveys (DGGS) personnel collected rock samples while mapping the bedrock geology along the Alaska Highway corridor between Delta Junction and the Canada border. The purpose of this DGGS Raw Data File is to present the 40Ar/39Ar results of samples that were selected for age dating and make them available for use to the public. This data release is one component of a multi-year DGGS project studying the geology, geohazards and resources along the proposed gas pipeline corridor.
    Supplemental_Information:
      The dated materials vary by sample and, in many cases, multiple minerals or mineral separates were analyzed from each rock sample. The three tables presented in this release are organized according to the hierarchy of data. We provide the location and description of each rock; summary age determination for each dated rock, mineral grain, or mineral separate; and the analytical measurements generated by each heating step. The values in the fields: Sample_Id and Lab_Sample_Number are used within the tables and the report to cross reference rock sample and laboratory sample records. The DGGS metadata standard extends the FGDC standard to include elements that are required to facilitate our internal data management. These elements, referred to as "layers," group and describe files that have intrinsic logical or topological relationships and correspond to subdirectories within the data distribution package. The metadata layer provides the metadata or other documentation files. Attribute information for each data layer is described in this metadata file under the "Entity_and_Attribute_Information" section. Data layer contents:  
      >sample-location-details:    Identification numbers, GPS coordinates, and description of each sample. 
      >step-heating-data:    The root 40Ar/39Ar analytical data table. This file lists the power output levels and resultant measurements from each sample run. 
      >interpretive-details:    Summary of 40Ar/39Ar radiometric ages of samples in this report and other interpretive details.
  Time_Period_of_Content:
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date: 2009
        Ending_Date: 2013
    Currentness_Reference: publication date
  Status:
    Progress: complete
    Maintenance_and_Update_Frequency: None planned
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: -144.728390
      East_Bounding_Coordinate: -141.359559
      North_Bounding_Coordinate: 63.841939
      South_Bounding_Coordinate: 62.902474
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: ISO 19115 Topic Category
      Theme_Keyword: geoscientificInformation
    Theme:
      Theme_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys
      Theme_Keyword: 40Ar/39Ar
      Theme_Keyword: Age Dates
      Theme_Keyword: Analyses and Sampling
      Theme_Keyword: Analytical Lab Results
      Theme_Keyword: Analytical Results
      Theme_Keyword: Ar-Ar
      Theme_Keyword: Bedrock
      Theme_Keyword: Bedrock Geology
      Theme_Keyword: Geochronology
      Theme_Keyword: Geology
      Theme_Keyword: Lab Methods
      Theme_Keyword: Sample Location
    Place:
      Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys
      Place_Keyword: Alaska Highway Corridor
      Place_Keyword: Mount Hayes Quadrangle
      Place_Keyword: Nabesna Quadrangle
      Place_Keyword: Tanacross Quadrangle
    Stratum:
      Stratum_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys
      Stratum_Keyword: Yukon-Tanana Terrane
      Stratum_Keyword: Yukon-Tanana Upland
    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
  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: GIS 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_Electronic_Mail_Address: dggsgis@alaska.gov
      Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays
  Data_Set_Credit: This project was supported by Alaska State Capital Improvement Project funding. Partial funding for mapping and 40Ar/39Ar geochronology in the Mt. Hayes C-1, C-2, D-1, and D-2 quadrangles was also provided through the U.S. Geological Survey STATEMAP program under award number 07HQAG0076. Samples in this report were collected by Larry Freeman, Melanie Werdon, Richard Lessard, and Diana Solie of DGGS, and Rainer Newberry of University of Alaska Fairbanks Department of Geology & Geophysics.
  Cross_Reference:
    Citation_Information:
      Originator: Carver, G.A.
      Originator: Bemis, S.P.
      Originator: Solie, D.N.
      Originator: Castonguay, S.R.
      Originator: Obermiller, K.E.
      Publication_Date: 2010
      Title: Active and potentially active faults in or near the Alaska Highway corridor, Dot Lake to Tetlin Junction, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2010-1
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 42 p
      Online_Linkage: http://dx.doi.org/10.14509/21121
  Cross_Reference:
    Citation_Information:
      Originator: Carver, G.A.
      Originator: Bemis, S.P.
      Originator: Solie, D.N.
      Originator: Obermiller, K.E.
      Publication_Date: 2008
      Title: Active and potentially active faults in or near the Alaska Highway corridor, Delta Junction to Dot Lake, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2008-3D
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 32 p
      Online_Linkage: http://dx.doi.org/10.14509/17901
  Cross_Reference:
    Citation_Information:
      Originator: Hubbard, T.D.
      Originator: Reger, R.D.
      Publication_Date: 2010
      Title: Engineering - geologic map of the Alaska Highway corridor, Robertson River to Tetlin Junction, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2009-6B
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 4 sheets, scale 1:63,360
      Online_Linkage: http://dx.doi.org/10.14509/19742
  Cross_Reference:
    Citation_Information:
      Originator: Hubbard, T.D.
      Originator: Reger, R.D.
      Originator: Gallagher, P.E.
      Publication_Date: 2013
      Title: Engineering - geologic map of the Alaska Highway corridor, Tetlin Junction to Canada border, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2012-1B
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 2 sheets, scale 1:63,360
      Online_Linkage: http://dx.doi.org/10.14509/24624
  Cross_Reference:
    Citation_Information:
      Originator: Koehler, R.D.
      Originator: Carver, G.A.
      Publication_Date: 2012
      Title: Active and potentially active faults along the Alaska Highway corridor, Tetlin Junction to the Canada border
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2012-2
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 23 p
      Online_Linkage: http://dx.doi.org/10.14509/23923
  Cross_Reference:
    Citation_Information:
      Originator: Koehler, R.D.
      Originator: Woods, R.-E.F.
      Publication_Date: 2013
      Title: Paleoseismic and LiDAR investigations along the Cathedral Rapids and Dot "T" Johnson faults, interior Alaska
      Series_Information:
        Series_Name: Report of Investigation
        Issue_Identification: RI 2013-4
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 21 p
      Online_Linkage: http://dx.doi.org/10.14509/26761
  Cross_Reference:
    Citation_Information:
      Originator: Reger, R.D.
      Originator: Hubbard, T.D.
      Publication_Date: 2010
      Title: Reconnaissance interpretation of 1978-1983 permafrost, Alaska Highway corridor, Robertson River to Tetlin Junction, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2009-6C
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 13 p., 4 sheets, scale 1:63,360
      Online_Linkage: http://dx.doi.org/10.14509/19743
  Cross_Reference:
    Citation_Information:
      Originator: Reger, R.D.
      Originator: Solie, D.N.
      Publication_Date: 2008
      Title: Engineering - geologic map, Alaska Highway corridor, Delta Junction to Dot Lake, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2008-3B
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 2 sheets, scale 1:63,360
      Online_Linkage: http://dx.doi.org/10.14509/17981
  Cross_Reference:
    Citation_Information:
      Originator: Reger, R.D.
      Originator: Solie, D.N.
      Publication_Date: 2008
      Title: Reconnaissance interpretation of permafrost, Alaska Highway corridor, Delta Junction to Dot Lake, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2008-3C
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 10 p., 2 sheets, scale 1:63,360
      Online_Linkage: http://dx.doi.org/10.14509/17621
  Cross_Reference:
    Citation_Information:
      Originator: Reger, R.D.
      Originator: Hubbard, T.D.
      Originator: Carver, G.A.
      Publication_Date: 2011
      Title: Surficial geology of Alaska Highway corridor, Robertson River to Tetlin Junction, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2009-6A
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 53 p., 4 sheets, scale 1:63,360
      Online_Linkage: http://dx.doi.org/10.14509/19741
  Cross_Reference:
    Citation_Information:
      Originator: Reger, R.D.
      Originator: Hubbard, T.D.
      Originator: Gallagher, P.E.
      Publication_Date: 2012
      Title: Reconnaissance interpretation of 1978-1981 permafrost, Alaska Highway corridor, Tetlin Junction to Canada border, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2012-1C
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 27 p., 2 sheets, scale 1:63,360
      Online_Linkage: http://dx.doi.org/10.14509/23444
  Cross_Reference:
    Citation_Information:
      Originator: Reger, R.D.
      Originator: Hubbard, T.D.
      Originator: Gallagher, P.E.
      Publication_Date: 2012
      Title: Surficial geology of the Alaska Highway corridor, Tetlin Junction to Canada border, Alaska
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2012-1A
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 25 p., 2 sheets, scale 1:63,360
      Online_Linkage: http://dx.doi.org/10.14509/23443
  Cross_Reference:
    Citation_Information:
      Originator: Reger, R.D.
      Originator: Stevens, D.S.P.
      Originator: Solie, D.N.
      Publication_Date: 2008
      Title: Surficial-geologic map, Delta Junction to Dot Lake, Alaska Highway corridor
      Series_Information:
        Series_Name: Preliminary Interpretive Report
        Issue_Identification: PIR 2008-3A
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 48 p., 2 sheets, scale 1:63,360
      Online_Linkage: http://dx.doi.org/10.14509/17961
  Cross_Reference:
    Citation_Information:
      Originator: Solie, D.N.
      Originator: Werdon, M.B.
      Originator: Newberry, R.J.
      Originator: Freeman, L.K.
      Originator: Lessard, R.R.
      Publication_Date: 2008
      Title: Major-oxide, minor-oxide, trace-element and geochemical data from rocks collected in the Alaska Highway corridor Mount Hayes Quadrangle, Alaska in 2006 and 2007
      Series_Information:
        Series_Name: Raw Data File
        Issue_Identification: RDF 2008-2 v. 1.0.1
      Publication_Information:
        Publication_Place: Fairbanks, Alaska, United States
        Publisher: Alaska Division of Geological & Geophysical Surveys
      Other_Citation_Details: 23 p
      Online_Linkage: http://dx.doi.org/10.14509/16021
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report: Coordinates of sample locations were determined by the geologists in the field using handheld GPS units. Sample numbers were recorded in the field on sample bags and on field note sheets. The sample numbers were transcribed into an Access database by a field assistant. The sample location table was generated from the database and was cross checked for consistency against the sample numbers recorded on the bags. Laboratory sample numbers were generated by the UAF geochronology lab from the a list provided by DGGS. See text report for additional discussion of laboratory procedures. Lab results and interpretations were examined by the DGGS geologists to ensure that they are reasonable given the geologic context of the sample.
  Logical_Consistency_Report: No topologic relationships are present in the data. We plotted the data points using GIS software to ensure that they are correctly located and we visually reviewed the sample identification numbers and other attribute values to ensure that they are free of typological errors.
  Completeness_Report: These analyses were completed throughout the duration of the project and subsequently compiled into a single report. Users should note that the interpretive summaries that are provided in the text report have been lightly edited for clarity but are generally provided as received. In a few cases the lab did not specifically record the type of dated material (mineral separate versus single grain). Based on subsequent personal correspondence with lab staff, we indicate that the dated material type is "mineral separate" for all samples that were not explicitly described as single grain or whole rock within the text report.
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report: Coordinates of sample locations were determined by the geologists in the field using handheld GPS units. Estimated position errors calculated by GPS units averaged approximately 6 meters.
  Lineage:
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator: Lanphere, M.A.
          Originator: Dalrymple, G.B.
          Publication_Date: 2000
          Title: First-principles calibration of 38Ar tracers :implications for the ages of 40Ar/39Ar fluence monitors
          Series_Information:
            Series_Name: Professional Paper
            Issue_Identification: P 1621
          Publication_Information:
            Publication_Place: United States
            Publisher: U.S. Geological Survey
          Other_Citation_Details: 10 p
          Online_Linkage: http://www.dggs.alaska.gov/pubs/id/16622
      Type_of_Source_Media: paper
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Single_Date/Time:
            Calendar_Date: 2000
        Source_Currentness_Reference: publication date
      Source_Citation_Abbreviation: Lanphere, M.A. and Dalrymple, G.B., 2000
      Source_Contribution: sample preparation
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator: Samson, S.D.
          Originator: Alexander, E.C.
          Publication_Date: 1987
          Title: Calibration of the inter-laboratory 40Ar/39Ar dating standard, MMhb-1
          Series_Information:
            Series_Name: Isotope Geoscience Section
            Issue_Identification: v. 66
          Publication_Information:
            Publication_Place: Netherlands
            Publisher: European Association of Geochemistry
      Type_of_Source_Media: paper
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Single_Date/Time:
            Calendar_Date: 1987
        Source_Currentness_Reference: publication date
      Source_Citation_Abbreviation: Samson, S.D. and Alexander, E.C., 1987
      Source_Contribution: sample preparation
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator: York, Derek
          Originator: Hall, C.M
          Originator: Yanase, Yotaro
          Originator: Hanes, J.A
          Publication_Date: 1981
          Title: 40Ar/39Ar dating of terrestrial minerals with a continuous laser
          Series_Information:
            Series_Name: Geophysical Research Letters
            Issue_Identification: v. 8, n. 11
          Publication_Information:
            Publication_Place: United States
            Publisher: American Geophysical Union
      Type_of_Source_Media: paper
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Single_Date/Time:
            Calendar_Date: 1981
        Source_Currentness_Reference: publication date
      Source_Citation_Abbreviation: York, Derek and others, 1981
      Source_Contribution: sample analysis
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator: Layer, P.W
          Originator: Hall, C.M
          Originator: York, Derek
          Publication_Date: 1987
          Title: The derivation of 40Ar/39Ar age spectra of single grains of hornblende and biotite by laser step-heating
          Series_Information:
            Series_Name: Geophysical Research Letters
            Issue_Identification: v. 14, n. 7
          Publication_Information:
            Publication_Place: United States
            Publisher: American Geophysical Union
      Type_of_Source_Media: paper
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Single_Date/Time:
            Calendar_Date: 1987
        Source_Currentness_Reference: publication date
      Source_Citation_Abbreviation: Layer, P.W and others, 1987
      Source_Contribution: sample analysis
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator: Layer, P.W
          Publication_Date: 2000
          Title: Argon-40/Argon-39 age of the El'gygytgyn impact event, Chukotka, Russia
          Series_Information:
            Series_Name: Meteroritics and Planetary Science
            Issue_Identification: v. 35, n. 3
          Publication_Information:
            Publication_Place: United States
            Publisher: Meteoritical Society
      Type_of_Source_Media: paper
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Single_Date/Time:
            Calendar_Date: 2000
        Source_Currentness_Reference: publication date
      Source_Citation_Abbreviation: Layer, P.W, 2000
      Source_Contribution: sample analysis
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator: McDougall, Ian
          Originator: Harrison, T.M
          Publication_Date: 1999
          Title: Geochronology and thermochronology by the 40Ar/39Ar method, 2nd ed.
          Publication_Information:
            Publication_Place: United States
            Publisher: Oxford University Press
      Type_of_Source_Media: paper
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Single_Date/Time:
            Calendar_Date: 1999
        Source_Currentness_Reference: publication date
      Source_Citation_Abbreviation: McDougall, Ian and Harrison, T.M, 1999
      Source_Contribution: sample analysis
    Process_Step:
      Process_Description: Fieldwork - Field geologists collected rock samples from the surface or within 0.5 m of the surface. Care was taken to collect fresh, unweathered samples representative of igneous rock types in the map area. Locations were recorded using handheld GPS units with an estimated horizontal accuracy of approximately 10 m. Samples were collected during the 2006 through 2009 field seasons.
      Process_Date: 2009
    Process_Step:
      Process_Description: Sample preparation - The selected rock samples were submitted to the University of Alaska Fairbanks Geochronology Laboratory. There the samples were crushed, washed, and sieved to either 100-250 or 250-500 micron size fractions, and hand-picked for date-able mineral phases. The monitor mineral MMhb-1 (Samson, S.D. and Alexander, E.C., 1987) with an age of 513.9 Ma (Lanphere, M.A. and Dalrymple, G.B., 2000) was used to monitor neutron flux (and calculate the irradiation parameter, J). The samples and standards were wrapped in aluminum foil and loaded into aluminum cans of 2.5 cm diameter and 6 cm height. The samples were irradiated in position 5c of the uranium-enriched research reactor of McMaster University in Hamilton, Ontario, Canada, for 20 megawatt-hours.
      Source_Used_Citation_Abbreviation: Lanphere, M.A. and Dalrymple, G.B., 2000
      Source_Used_Citation_Abbreviation: Samson, S.D. and Alexander, E.C., 1987
      Process_Date: 2010
    Process_Step:
      Process_Description: Sample analysis - Upon their return from the reactor, the samples and monitors were loaded into 2-mm-diameter holes in a copper tray that was then loaded in an ultra-high-vacuum extraction line. The monitors were fused, and samples heated, using a 6-watt argon-ion laser following the technique described in York and others (1981), Layer and others (1987), and Layer (2000). Argon purification was achieved using a liquid nitrogen cold trap and a SAES Zr-Al getter at 400 degrees C. The samples were analyzed in a VG-3600 mass spectrometer at the Geophysical Institute, University of Alaska Fairbanks. The argon isotopes measured were corrected for system blank and mass discrimination, as well as calcium, potassium, and chlorine interference reactions following procedures outlined in McDougall and Harrison (1999). See text report for additional description of the analytical procedures, parameters, and a comprehensive bibliography.
      Source_Used_Citation_Abbreviation: York, Derek and others, 1981
      Source_Used_Citation_Abbreviation: Layer, P.W and others, 1987
      Source_Used_Citation_Abbreviation: Layer, P.W, 2000
      Source_Used_Citation_Abbreviation: McDougall, Ian and Harrison, T.M, 1999
      Process_Date: 2010
Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: point
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Geodetic_Model:
      Horizontal_Datum_Name: North American Datum of 1927
      Ellipsoid_Name: North American Datum of 1927
      Semi-major_Axis: 6378206.4
      Denominator_of_Flattening_Ratio: 294.9786982
Entity_and_Attribute_Information:
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: rdf2013-8-sample-location-details.csv
      Entity_Type_Definition: Identification numbers, GPS coordinates, and description of each sample.
      Entity_Type_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Entity_Attribute_Layer_Name: sample-location-details
    Attribute:
      Attribute_Label: Sample_Id
      Attribute_Definition: Label assigned to identify the field location where a sample was collected and to identify the sample in related project publications.
      Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Attribute_Domain_Values:
        Unrepresentable_Domain: Generic example of a station identifier: 20YYAAA9999X: YY=last two digits of year, AAA=geologist's initials (one to three characters), 9999=unique station number, X= optional alpha character which indicates that multiple samples were collected at a given location or that multiple observations were recorded in the project database. The initials used by the geologists who collected samples for this project are: RL = Lessard, R.R.; MBW = Werdon, M.B.; DNS = Solie, D.N.; RN = Newberry, R.J.; LF = Freeman, L.K.
    Attribute:
      Attribute_Label: Latitude
      Attribute_Definition: Latitude, NAD27
      Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 62.902474
          Range_Domain_Maximum: 63.841939
    Attribute:
      Attribute_Label: Longitude
      Attribute_Definition: Longitude, NAD27
      Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: -144.72839
          Range_Domain_Maximum: -141.359559
    Attribute:
      Attribute_Label: Description
      Attribute_Definition: Description of the sample
      Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Attribute_Domain_Values:
        Unrepresentable_Domain: A brief sample description; note that the values in this field may exceed 255 characters
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: rdf2013-8-step-heating-data.csv
      Entity_Type_Definition: The root 40Ar/39Ar analytical data table. This file lists the power output levels and resultant measurements from each sample run.
      Entity_Type_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Entity_Attribute_Layer_Name: step-heating-data
    Attribute:
      Attribute_Label: Sample_Id
      Attribute_Definition: Label assigned to identify the field location where a sample was collected and to identify the sample in related project publications.
      Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Attribute_Domain_Values:
        Unrepresentable_Domain: Generic example of a station identifier: 20YYAAA9999X: YY=last two digits of year, AAA=geologist's initials (one to three characters), 9999=unique station number, X= optional alpha character which indicates that multiple samples were collected at a given location or that multiple observations were recorded in the project database. The initials used by the geologists who collected samples for this project are: RL = Lessard, R.R.; MBW = Werdon, M.B.; DNS = Solie, D.N.; RN = Newberry, R.J.; LF = Freeman, L.K.
    Attribute:
      Attribute_Label: Lab_Sample_Number
      Attribute_Definition: Sample identifier assigned by the laboratory, note that these numbers correspond to spectra plot labels provided in the appendix of the text report
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Unrepresentable_Domain: Lab numbers generally combine the DGGS sample number and the name of the dated mineral, but they do not follow a specific naming convention.
    Attribute:
      Attribute_Label: Laser_mW
      Attribute_Definition: Laser output level in megawatts
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: Integrated
          Enumerated_Domain_Value_Definition: "Integrated" values in the Laser_mW  column indicate that this row provides the age and errors given by the total gas measured and the values are equivalent to a potassium-argon (K-Ar) age.
          Enumerated_Domain_Value_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 300
          Range_Domain_Maximum: 9000
          Attribute_Units_of_Measure: megawatts
    Attribute:
      Attribute_Label: Cum39Ar
      Attribute_Definition: Cumulative ratio of 39Argon released at this step
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: NULL
          Enumerated_Domain_Value_Definition: Blank (NULL) field values indicate that a value was not provided by the lab.
          Enumerated_Domain_Value_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 0.0025
          Range_Domain_Maximum: 1
    Attribute:
      Attribute_Label: Me40Ar39Ar
      Attribute_Definition: Measured 40Ar/39Ar ratio for each heating step, corrected for blank and 39Ar decay
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 7.7367
          Range_Domain_Maximum: 427.3728
    Attribute:
      Attribute_Label: Er40Ar39Ar
      Attribute_Definition: The one sigma error for each 40Ar/39Ar measurement
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 0.026
          Range_Domain_Maximum: 9.8057
    Attribute:
      Attribute_Label: Me37Ar39Ar
      Attribute_Definition: The ratio of measured 37Ar to measured 39Ar for each heating interval for each sample corrected for blank and 37Ar and 39Ar decay
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: -0.0009
          Range_Domain_Maximum: 119.75993
    Attribute:
      Attribute_Label: Er37Ar39Ar
      Attribute_Definition: The one sigma error for each 37Ar/39Ar measurement
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 0.0001
          Range_Domain_Maximum: 2.98741
    Attribute:
      Attribute_Label: Me36Ar39Ar
      Attribute_Definition: Ratio of measured 36Ar to measured 39Ar for each step interval for each sample corrected for blank and 39Ar decay
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: -0.0764
          Range_Domain_Maximum: 1.32089
    Attribute:
      Attribute_Label: Er36Ar39Ar
      Attribute_Definition: The one sigma error for each 36Ar/39Ar measurement
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 0
          Range_Domain_Maximum: 0.06435
    Attribute:
      Attribute_Label: Atm40Ar
      Attribute_Definition: Percent of 40Ar which is atmospheric in composition at each step level
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: -199.3
          Range_Domain_Maximum: 111.3
          Attribute_Units_of_Measure: percent
    Attribute:
      Attribute_Label: MeCaK
      Attribute_Definition: Ratio of Calcium to Potassium as determined from 37Ar/39Ar
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: -0.0016
          Range_Domain_Maximum: 240.0451
    Attribute:
      Attribute_Label: ErCaK
      Attribute_Definition: The one sigma error for each Ca/K determination
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 0.0002
          Range_Domain_Maximum: 6.5411
    Attribute:
      Attribute_Label: MeClK
      Attribute_Definition: Ratio of Chlorine to Potassium as determined from 38Ar/39Ar
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: -0.00116
          Range_Domain_Maximum: 0.2019
    Attribute:
      Attribute_Label: ErClK
      Attribute_Definition: The one sigma error for each Cl/K determination
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 0
          Range_Domain_Maximum: 0.01822
    Attribute:
      Attribute_Label: 40ArRad39ArK
      Attribute_Definition: Ratio of radiogenic 40Ar to 39Ar derived from potassium
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: -5.325
          Range_Domain_Maximum: 37.1353
    Attribute:
      Attribute_Label: Er40ArRad39ArK
      Attribute_Definition: One sigma error for each 40ArRad/39ArK value
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 0.03
          Range_Domain_Maximum: 19.2562
    Attribute:
      Attribute_Label: AgeMa
      Attribute_Definition: Calculated age for each temperature step for each sample
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: -36.2
          Range_Domain_Maximum: 234.2
          Attribute_Units_of_Measure: Ma
    Attribute:
      Attribute_Label: ErAgeMa
      Attribute_Definition: One sigma error of the age determination of each heating step
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 0.2
          Range_Domain_Maximum: 128.9
          Attribute_Units_of_Measure: Ma
    Attribute:
      Attribute_Label: WeightedAverageOfJFromStandards
      Attribute_Definition: J value, calculated from the weighted average of standards placed in various positions in the nuclear reactor
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: 2.666e-03 ± 1.336e-05
          Enumerated_Domain_Value_Definition: 0.002666 ± 0.00001336
          Enumerated_Domain_Value_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: 3.733e-03 ± 1.265e-05
          Enumerated_Domain_Value_Definition: 0.003733 ± 0.00001265
          Enumerated_Domain_Value_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: 3.578e-03 ± 1.111e-05
          Enumerated_Domain_Value_Definition: 0.003578 ± 0.00001111
          Enumerated_Domain_Value_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: 3.411e-03 ± 1.051e-05
          Enumerated_Domain_Value_Definition: 0.003411 ±0.00001051
          Enumerated_Domain_Value_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: 3.463e-03 ± 1.087e-05
          Enumerated_Domain_Value_Definition: 0.003463 ± 0.00001087
          Enumerated_Domain_Value_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: rdf2013-8-interpretive-details.csv
      Entity_Type_Definition: Summary of 40Ar/39Ar radiometric ages of samples in this report and other interpretive details.
      Entity_Type_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Entity_Attribute_Layer_Name: interpretive-details
    Attribute:
      Attribute_Label: Sample_Id
      Attribute_Definition: Label assigned to identify the field location where a sample was collected and to identify the sample in related project publications.
      Attribute_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Attribute_Domain_Values:
        Unrepresentable_Domain: Generic example of a station identifier: 20YYAAA9999X: YY=last two digits of year, AAA=geologist's initials (one to three characters), 9999=unique station number, X= optional alpha character which indicates that multiple samples were collected at a given location or that multiple observations were recorded in the project database. The initials used by the geologists who collected samples for this project are: RL = Lessard, R.R.; MBW = Werdon, M.B.; DNS = Solie, D.N.; RN = Newberry, R.J.; LF = Freeman, L.K.
    Attribute:
      Attribute_Label: Dated_Material
      Attribute_Definition: Indicates the type of material that was used for analysis
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Unrepresentable_Domain: The type of material that was selected for dating varied according to mineral composition and grainsize of the submitted rock sample. This field specifies whether the age was derived from a mineral separate (generally 1 to 10 individual crystals dated together as a single run), a single crystal, or the whole rock.
    Attribute:
      Attribute_Label: Mineral
      Attribute_Definition: Indicates the mineral that was used for analysis
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Unrepresentable_Domain: The minerals selected for dating were: biotite, hornblende, or muscovite.
    Attribute:
      Attribute_Label: Lab_Sample_Number
      Attribute_Definition: Sample identifier assigned by the laboratory, note that these numbers correspond to spectra plot labels provided in the appendix of the text report
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Unrepresentable_Domain: Lab numbers generally combine the DGGS sample number and the name of the dated mineral, but they do not follow a specific naming convention.
    Attribute:
      Attribute_Label: Integrated_Age_Ma
      Attribute_Definition: Integrated age and age error in million years
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Unrepresentable_Domain: The values are a concatenation of the integrated age determination and the calculated error associated with the integrated age determination
    Attribute:
      Attribute_Label: Plateau_Age_Ma
      Attribute_Definition: Plateau age and age error in million years
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Unrepresentable_Domain: The values are a concatenation of the plateau age determination and the calculated error associated with the plateau age determination
    Attribute:
      Attribute_Label: Plateau_Percent_39ar
      Attribute_Definition: Value in percent of the 39 Ar used in that portion of the spectrum to determine the plateau age
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: NULL
          Enumerated_Domain_Value_Definition: Blank (NULL) field values indicate that a value was not provided by the lab.
          Enumerated_Domain_Value_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 17.8
          Range_Domain_Maximum: 99
          Attribute_Units_of_Measure: percent
    Attribute:
      Attribute_Label: Plateau_MSWD
      Attribute_Definition: The mean square weighted deviation of the plateau age calculation
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: NULL
          Enumerated_Domain_Value_Definition: Blank (NULL) field values indicate that a value was not provided by the lab.
          Enumerated_Domain_Value_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 0.03
          Range_Domain_Maximum: 26
    Attribute:
      Attribute_Label: Plateau_Remarks
      Attribute_Definition: Comments and additional values that pertain to the plateau age determination method or interpretation.
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Unrepresentable_Domain: Free text
    Attribute:
      Attribute_Label: Isochron_Age
      Attribute_Definition: Isochon age and age error in million years
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Unrepresentable_Domain: The values are a concatenation of the isochron age determination and the calculated error associated with the isochron age determination
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: NULL
          Enumerated_Domain_Value_Definition: Blank (NULL) field values indicate that a value was not provided by the lab.
          Enumerated_Domain_Value_Definition_Source: Alaska Division of Geological & Geophysical Surveys
    Attribute:
      Attribute_Label: Isochron_MSWD
      Attribute_Definition: The mean square weighted deviation of the isochron age calculation
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Enumerated_Domain:
          Enumerated_Domain_Value: NULL
          Enumerated_Domain_Value_Definition: Blank (NULL) field values indicate that a value was not provided by the lab.
          Enumerated_Domain_Value_Definition_Source: Alaska Division of Geological & Geophysical Surveys
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 0.17
          Range_Domain_Maximum: 2.6
    Attribute:
      Attribute_Label: Isochron_Remarks
      Attribute_Definition: Comments and additional values that pertain to the isochron age determination method or interpretation.
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Unrepresentable_Domain: Free text
    Attribute:
      Attribute_Label: Lab_Notes
      Attribute_Definition: Additional information provided by the lab
      Attribute_Definition_Source: University of Alaska Fairbanks Geochronology Laboratory
      Attribute_Domain_Values:
        Unrepresentable_Domain: Free text
Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: Alaska Division of Geological & Geophysical Surveys
      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 (http://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 2013-8
  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: http://dx.doi.org/10.14509/26841
    Fees: Free download
Metadata_Reference_Information:
  Metadata_Date: 20140107
  Metadata_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
  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: http://www.dggs.alaska.gov/metadata/dggs.ext
    Profile_Name: dggs metadata extensions