Uranium-Lead Ages, Hafnium Isotope Ratios, and Trace Element Concentrations by Laser-Ablation Split Stream (LASS) Analysis of Igneous Zircons from the Darby Mountains Area, Seward Peninsula, Alaska

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: Drewes-Todd, Elizabeth K. (ORC ID: 0000-0003-0692-3714)
Originator: Todd, Erin (ORCID: 0000-0002-4871-9730)
Originator: Kylander-Clark, Andrew R.C. (ORCID: 0000-0002-4034-644x)
Originator: Pongratz, Alan L. (ORCID: 0000-0002-1174-7711)
Publication_Date: 20230124
Title:
Uranium-Lead Ages, Hafnium Isotope Ratios, and Trace Element Concentrations by Laser-Ablation Split Stream (LASS) Analysis of Igneous Zircons from the Darby Mountains Area, Seward Peninsula, Alaska
Geospatial_Data_Presentation_Form: tabular digital data
Publication_Information:
Publication_Place: Anchorage, Alaska
Publisher: U.S. Geological Survey, Alaska Science Center
Other_Citation_Details:
Suggested Citation: Drewes-Todd, E.K., Todd, E., Kylander-Clark, A.R.C., Pongratz, A.L. 2023, Uranium-Lead ages, Hafnium isotope ratios, and trace element concentrations by Laser-Ablation Split Stream (LASS) analysis of igneous zircons from the Darby Mountains area, Seward Peninsula, Alaska: U.S. Geological Survey data release, https://doi.org/10.5066/P9JKR2J6
Online_Linkage: https://doi.org/10.5066/P9JKR2J6
Larger_Work_Citation:
Citation_Information:
Originator: U.S. Geological Survey, Alaska Science Center
Publication_Date: 2016
Title:
Petrogenesis and Mineralization of the Darby and Kachauik Plutons, Seward Peninsula, Alaska
Geospatial_Data_Presentation_Form: website
Series_Information:
Series_Name: Alaska Science Portal
Issue_Identification: 386
Publication_Information:
Publication_Place: Anchorage, Alaska
Publisher: U.S. Geological Survey, Alaska Science Center
Other_Citation_Details:
This is a link to the broader USGS Alaska Science Center research project supported by these data. Users will find a description of the research project and links to associated reports, publications, and data products.
Online_Linkage: https://alaska.usgs.gov/portal/project.php?project_id=386
Description:
Abstract:
This data set contains uranium–lead (U-Pb) isotopic data and ages, hafnium (Hf) isotope data, and trace element concentrations of zircon from igneous rocks collected from the Darby Mountains area of the Seward Peninsula, Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted in 2017. The data tables accompanying this data release report the isotopic composition of U and thorium (Th) measured in each grain, ratios of 207Pb and 206Pb and 235U and 238U, and the age of each grain, plus trace element abundances from the same ablated aliquot, including phosphorus (P), vanadium (V), strontium (Sr), high field strength elements (HFSE), and rare earth elements (REE). Reported Hf (and lutetium, Lu) isotope data includes 176Hf/177Hf, 176Lu/177Hf, and 178Hf/177Hf ratios, calculated epsilon Hf values, and age-corrected isotope ratios and epsilon values.
Purpose:
U-Pb zircon dates and compositions from igneous rocks aid in the interpretation of the age of original formation (e.g. crystallization age) and sources of igneous rocks with a variety of compositions. These data will be used in support of geological maps, reports, and papers that describe the geological framework and mineral resource potential of the region.
Supplemental_Information:
Sample collection was funded by the Mineral Resources Program of the U.S. Geological Survey. Bulk rock samples were processed into concentrated mineral separates by ZirChron LLC and analyzed at the laser-ablation split-stream (LASS) laboratory at the University of California, Santa Barbara. The LASS configuration splits the laser-ablated aerosol stream between a quadrupole inductively coupled plasma spectrometer (Q-ICPMS) and a multi-collector inductively coupled plasma spectrometer (MC-ICP-MS), enabling simultaneous measurements of ages, trace elements, and Hf isotopes on the same volume of ablated material. U-Th-Pb isotopes and trace element concentrations were analyzed by Q-ICPMS, while Hf isotopes were analyzed by MC-ICP-MS.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2023
Currentness_Reference: publication date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -162.94
East_Bounding_Coordinate: -162.26
North_Bounding_Coordinate: 65.18
South_Bounding_Coordinate: 64.33
Keywords:
Theme:
Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:ASC513
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: environment
Theme:
Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: geochronology
Theme_Keyword: igneous rocks
Theme_Keyword: radiometric dating
Theme:
Theme_Keyword_Thesaurus: GeoRef Thesaurus
Theme_Keyword: age-dating
Theme_Keyword: Lu/Hf
Theme_Keyword: U/Pb
Theme_Keyword: U/Th/Pb
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: laser-ablation split-stream
Theme_Keyword: LASS
Theme_Keyword:
laser-ablation multi collector inductively coupled plasma mass spectrometry
Theme_Keyword: LA-MC-ICPMS
Theme_Keyword: trace elements
Place:
Place_Keyword_Thesaurus: USGS Geographic Names Information System (GNIS)
Place_Keyword: Alaska
Place_Keyword: Darby Mountains
Place_Keyword: Seward Peninsula
Access_Constraints: None
Use_Constraints:
It is requested that the authors and the USGS Alaska Science Center be cited for any subsequent publications that reference this dataset.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey, Alaska Science Center
Contact_Address:
Address_Type: Mailing and Physical
Address: 4210 University Drive
City: Anchorage
State_or_Province: Alaska
Postal_Code: 99508
Country: USA
Contact_Voice_Telephone: 907-786-7000
Contact_Electronic_Mail_Address: ascweb@usgs.gov
Cross_Reference:
Citation_Information:
Originator: Drewes-Todd, E.K.
Originator: Case, G.N.
Originator: Kreiner, D.C.
Originator: Karl, S.M.
Originator: Box, S.E.
Originator: Allard, A.J.
Originator: Pongratz, A.L.
Publication_Date: 2023
Title:
Geochemical Analysis, Major and Trace Element Data from the Darby Mountains Area, Seward Peninsula, Alaska
Geospatial_Data_Presentation_Form: tabular digital data
Series_Information:
Series_Name: U.S. Geological Survey data release
Issue_Identification: doi:10.5066/P9DY3M3I
Publication_Information:
Publication_Place: online
Publisher: U.S. Geological Survey, Alaska Science Center
Other_Citation_Details:
Drewes-Todd, E.K., Case, G.N., Kreiner, D.C., Karl, S.M., Box, S.E., Allard, A.J., and Pongratz, A.L., 2023, Geochemical Analysis, Major and Trace Element Data from the Darby Mountains Area, Seward Peninsula, Alaska: U.S. Geological Survey data release, https://doi.org/10.5066/P9DY3M3I
Online_Linkage: https://doi.org/10.5066/P9DY3M3I
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
Each run in each analytical session began with a round-robin of multiple analyses of zircon reference materials (RM), including 91500, GJ1, Plesovice, Mud Tank, and Temora2 to constrain stable isotope fractionation and measured 206Pb/238U and 207Pb/206Pb ratios was at or near 1 percent. The same zircon RM were interleaved among samples, with one analysis of 91500 plus a rotation of the other four RM run after every eighth sample spot. All measured isotopic ratios are reported with associated analytical uncertainty. Hf isotope ratios measured on these standard reference materials agree within error to accepted values. Trace element data are calibrated with analysis of matrix-matched reference materials (91500 and GJ1) interleaved among samples.
Logical_Consistency_Report:
No unexpected values are found in these data. Blank cells in the data tables indicate values were either not provided, not measured, unresolvable within instrument parameters, or not calculated. The geochronological data provided in this data release may contain trailing zeros. If the CSV files are opened directly in Microsoft Excel, data values may be truncated.
Completeness_Report:
This dataset contains LASS procedural analysis on samples selected from within a geographically bounded area of interest in the eastern portion of the Seward Peninsula within the Darby Mountains. The dataset includes instances of failed analyses of specific grains due to instrumentation error.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
All samples collected in 2017 have horizontal positions measured using hand-held GPS units with positional accuracy of approximately 3 meters, within Datum NAD83. The location for samples collected prior to the year 2017 have been obtained from 1:63,360 scale topographic field sheets or field notebooks and converted from Datum NAD27 to NAD83.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: University of California, Santa Barbara
Publication_Date: 2022
Title:
Supplemental Info: Zircon U-Pb geochronology, Hf isotope and trace element concentration analytical methods using UCSB Laser-ablation Split Stream (LASS) Analysis
Geospatial_Data_Presentation_Form: publication
Publication_Information:
Publication_Place: Santa Barbara, California
Publisher: University of California, Santa Barbara
Other_Citation_Details:
This is a supplemental PDF document included in this data release. The file name is Supplemental_Info_Analytical_Methods_UCSB_LASS.pdf.
Type_of_Source_Media: pdf file
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2022
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: LASS Analytical Methods
Source_Contribution:
Provides detailed description of laboratory methods used in Laser Ablation Split-Stream (LASS) procedures.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Blichert-Toft, J.
Originator: Albarede, F.
Publication_Date: 1997
Title:
The Lu-Hf isotope geochemistry of chondrites and the evolution of the mantle-crust system
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Earth and Planetary Science Letters
Issue_Identification: 148(1):243-258
Publication_Information:
Publication_Place: online
Publisher: Elsevier
Other_Citation_Details:
Blichert-Toft, J., Albarede, F. 1997. The Lu-Hf isotope geochemistry of chondrites and the evolution of the mantle-crust system. Earth and Planetary Science Letters 148(1):243-258 doi:10.1016/S0012-821X(97)00040-X
Online_Linkage: https://doi.org/10.1016/S0012-821X(97)00040-X
Type_of_Source_Media: publication
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 1997
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: Blichert-Toft and Albarède, 1997
Source_Contribution: Calculation of age-corrected Hafnium values
Source_Information:
Source_Citation:
Citation_Information:
Originator: Ferry, J.M.
Originator: Watson, E.B.
Publication_Date: 2007
Title:
New thermodynamic models and revised calibrations for the Ti-in-zircon and Zr-in-rutile thermometers
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Contributions to Mineralogy and Petrology
Issue_Identification: 154(4):429-437
Publication_Information:
Publication_Place: online
Publisher: Springer Link
Other_Citation_Details:
Ferry, J.M., Watson, E.B. 2007. New thermodynamic models and revised calibrations for the Ti-in-zircon and Zr-in-rutile thermometers. Contributions to Mineralogy and Petrology 154(4):429-437 doi:10.1007/s00410-007-0201-0
Online_Linkage: https://doi.org/10.1007/s00410-007-0201-0
Type_of_Source_Media: publication
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2007
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: Ferry and Watson, 2007
Source_Contribution: Calculation of thermodynamic models and calibrations
Source_Information:
Source_Citation:
Citation_Information:
Originator: Griffin, W.L.
Originator: Pearson, N.J.
Originator: Belousova, E.A.
Originator: Jackson, S.E.
Originator: van Achterbergh, E.
Originator: O'Reilly, S.Y.
Originator: Shee, S.R.
Publication_Date: 2000
Title:
The Hf isotope composition of cratonic mantle: LAM-MC-ICPMS analysis of zircon megacrysts in kimberlites
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Geochimica et Cosmochimica Acta
Issue_Identification: 64(1):133-147
Publication_Information:
Publication_Place: online
Publisher: Elsevier
Other_Citation_Details:
Griffin, W.L., Pearson, N.J., Belousova, E.A., Jackson, S.E., van Achterbergh, E., O'Reilly, S.Y., Shee, S.R. 2000. The Hf isotope composition of cratonic mantle: LAM-MC-ICPMS analysis of zircon megacrysts in kimberlites. Geochimica et Cosmochimica Acta 64(1):133-147 doi:10.1016/S0016-7037(99)00343-9
Online_Linkage: https://doi.org/10.1016/S0016-7037(99)00343-9
Type_of_Source_Media: publication
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2000
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: Griffin et al., 2000
Source_Contribution: Analysis of Lutetium-Hafnium ratios
Source_Information:
Source_Citation:
Citation_Information:
Originator: Scherer, E.E.
Originator: Munker, C.
Originator: Mezger, K.
Publication_Date: 2001
Title: Calibration of the Lutetium-Hafnium clock
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Science
Issue_Identification: 293(5530):683-687
Publication_Information:
Publication_Place: online
Publisher: American Association for the Advancement of Science
Other_Citation_Details:
Scherer, E., Munker, C., Mezger, K. 2001. Calibration of the Lutetium-Hafnium clock. Science 293(5530):683-687 doi:10.1126/science.1061372
Online_Linkage: https://doi.org/10.1126/science.1061372
Type_of_Source_Media: publication
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2001
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: Scherer et al., 2001
Source_Contribution: Calculation of age-corrected Lutetium-Hafnium values
Process_Step:
Process_Description:
Zircon grains were separated from crushed and ground samples using standard magnetic and heavy liquid techniques, hand-picked under binocular microscope, and mounted in epoxy discs. The mounts were ground to expose the grain interior, further polished, and imaged using a digital camera mounted to a binocular picking microscope to identify any inclusions or other features such as cracks to be avoided during analysis. Detailed analytical procedures are described in the accompanying document included in this data package: "Supplemental_Info_Analytical_Methods_UCSB_LASS.pdf".
Process_Date: 2022
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: North American Datum of 1983 (NAD 83)
Ellipsoid_Name: Geodetic Reference System 1980
Semi-major_Axis: 6378137
Denominator_of_Flattening_Ratio: 298.257222101
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: geology_LASS_DataDictionary_DarbyMtns_DrewesTodd.csv
Entity_Type_Definition:
Table describing all fields in each table included in this data package. Includes field names, a brief description of each field, and the data units, if applicable. This table contains 132 records and is presented in comma separated value (.csv) format.
Entity_Type_Definition_Source: Author defined
Attribute:
Attribute_Label: TABLE
Attribute_Definition: Name of the data table the field is found in.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: geology_LASS_Geochronology_DarbyMtns_AK_Drewes.csv
Enumerated_Domain_Value_Definition: Filename of CSV data table
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: geology_LASS_SampleSummary_DarbyMtns_AK_Drewes.csv
Enumerated_Domain_Value_Definition: Filename of CSV data table
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: FIELD_NAME
Attribute_Definition: Field name found in data table listed in field 'TABLE'.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Attributes in this field are single words or concatenated abbreviations that describe the contents of the field.
Attribute:
Attribute_Label: FIELD_EXPLANATION
Attribute_Definition: Brief description of the contents of 'FIELD_NAME'.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Attributes in this field are brief descriptions of the contents of 'FIELD_NAME'.
Attribute:
Attribute_Label: UNITS
Attribute_Definition: The unit of measurement for applicable data fields.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: n/a
Enumerated_Domain_Value_Definition: not applicable
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: cps
Enumerated_Domain_Value_Definition: counts per second
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: decimal degrees
Enumerated_Domain_Value_Definition: unit of angular measure
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: degrees C
Enumerated_Domain_Value_Definition: degrees Celsius
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Ga
Enumerated_Domain_Value_Definition: Giga-annum, or billions of years before present
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Ma
Enumerated_Domain_Value_Definition: Mega-annum, or millions of years before present
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: ppm
Enumerated_Domain_Value_Definition: parts per million
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: um
Enumerated_Domain_Value_Definition: micrometers
Enumerated_Domain_Value_Definition_Source: Author defined
Detailed_Description:
Entity_Type:
Entity_Type_Label: geology_LASS_SampleSummary_DarbyMtns_DrewesTodd.csv
Entity_Type_Definition:
Table with sample information, including location, rock descriptions, hafnium isotope data, median trace element concentrations, and geochronology analysis summary data. This table contains 23 records and is presented in comma separated value (.csv) format.
Entity_Type_Definition_Source: Author defined
Attribute:
Attribute_Label: Index
Attribute_Definition:
Numeric identifier used for sorting purposes within this table only.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1
Range_Domain_Maximum: 23
Attribute:
Attribute_Label: Sample
Attribute_Definition: Sample number as collected in the field; USGS identifier.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Sample identifier; most labels consisting of the last two digits of the year collected, an abbreviation identifying the collector, and a number and possible suffix. Sample identifiers link to field Sample in table geology_LASS_Geochronology_DarbyMtns_AK_Drewes.csv.
Attribute:
Attribute_Label: LATITUDE
Attribute_Definition: Sample location latitude in decimal degrees, datum NAD83
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 64.3314
Range_Domain_Maximum: 65.1713
Attribute_Units_of_Measure: decimal degrees
Attribute_Measurement_Resolution: 0.0001
Attribute:
Attribute_Label: LONGITUDE
Attribute_Definition: Sample location longitude in decimal degrees, datum NAD83
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -162.2698
Range_Domain_Maximum: -162.9303
Attribute_Units_of_Measure: decimal degrees
Attribute_Measurement_Resolution: 0.0001
Attribute:
Attribute_Label: DATUM
Attribute_Definition:
Geodetic reference system model name attributed to collected sample location, as noted by the sample collector.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: NAD83
Enumerated_Domain_Value_Definition:
North American Datum, using a semi-major axis of 6378137.0m and a flattening ratio of 298.257223563
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: ROCK_CLASS
Attribute_Definition: Rock type (Igneous, metamorphic, or sedimentary).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Igneous
Enumerated_Domain_Value_Definition: Primary rock classification = Igneous
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: ROCK_NAME
Attribute_Definition:
Rock name, as described in original collector field notes. Blank cells are present where field notes were not available or collector did not describe sample.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain: Sample rock nomenclature.
Attribute:
Attribute_Label: ROCK_COMMENT
Attribute_Definition:
A more detailed rock description. Blank cells are present where field notes were not available or collector did not describe sample.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
This free text field contains a generally more detailed rock description than 'ROCK_NAME'.
Attribute:
Attribute_Label: UPb_Age_Interpretation
Attribute_Definition:
Interpretation whether an analyzed grain represents the main crystallization stage of the host rock, or "No confident age determined".
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Crystallization age
Enumerated_Domain_Value_Definition:
Analyzed grain represents the main crystallization stage of the host rock
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: No confident age determined
Enumerated_Domain_Value_Definition:
Indicates insufficient zircon grain populations or measurements available for reliable analysis
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: Mount
Attribute_Definition:
Internal laboratory alphanumeric identifier for a specific sample mount.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Values in this field consist of three letter initials followed by a two-digit number, denoting a specific and repeatable laboratory equipment configuration.
Attribute:
Attribute_Label: Session_Run
Attribute_Definition:
Year and month of analytical session, and Run sequence within that session, when analysis was conducted.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Values in this data set are a concatenation of the calendar year followed by a "/", the number associated with the calendar month, a two-digit number indicating the procedural sequence during the month indicated, the word "_RUN_", and a two-digit number. Multiple runs are indicated in certain cells.
Attribute:
Attribute_Label: Timestamp
Attribute_Definition:
Concatenation of date and time of analysis for individual analysis procedures.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 2018-05-14, 16:25:01
Range_Domain_Maximum: 2018-05-18_ 08:34:54
Attribute_Units_of_Measure: Date Time (YYYY-MM-DD hh:mm:ss) local time
Attribute:
Attribute_Label: Spot_Size_um
Attribute_Definition: Laser spot size during analyses, in micrometers (um).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Values in this field are concatenated numeric spot analysis sizes from the instrument in micrometers and the suffix 'um". Some samples were run more than once with more than one spot size, as indicated.
Attribute:
Attribute_Label: Laser_Run_Conditions
Attribute_Definition:
Laser run conditions during analysis; repetition rate (Hz), fluence (%) and Output (mJ).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
The attributes in this field are a concatenation of the frequency of the laser in Hz (cycles per second), power setting of the laser in % (percent), and output power setting of the laser in mJ (milliJoules). Additional comments are included if multiple settings or analytical sessions were used.
Attribute:
Attribute_Label: Comment_age
Attribute_Definition: Comments on sample age or analytical observations.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
The values in this data set include specific additional or amplifying remarks with regard to type of analysis or procedures. This is a free text field.
Attribute:
Attribute_Label: Comment_chem
Attribute_Definition:
Comments on sample trace elements or hafnium isotope observations. Blank cells may be present, indicating that no additional chemistry observations were made as a result of the procedures completed.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
The values in this data set include general observations regarding procedural results. This is a free text field.
Attribute:
Attribute_Label: Spots_total
Attribute_Definition:
Total number of measurements made on zircon grains for a sample population.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1
Range_Domain_Maximum: 34
Attribute:
Attribute_Label: Method
Attribute_Definition:
Analytical configuration used; "LASS," short for laser-ablation split-stream, indicates simultaneous quadrupole inductively coupled plasma spectrometer (Q-ICPMS) and multi-collector inductively coupled plasma spectrometer (LA-MC-ICP-MS) analyses, measuring U-Th-Pb and trace elements on Q-ICPMS and Hf isotopes on MC-ICP-MS.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: LASS
Enumerated_Domain_Value_Definition: Laser-ablation split-stream analytical configuration was used.
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: UPb_MEAS_USED
Attribute_Definition:
Number of zircon measurements per sample, out of the permissible measurements (i.e., total analyzed minus excluded), contributing to calculation of weighted means of U-Pb ages. "SHRIMP" indicates age shown is the published weighted mean age, from sources detailed in Supplement. Blank cells may be present, indicating no measurements were possible.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Attributes for this data set are 'single grain', and a series of results in the format 'X of Y', where 'X' indicates number of measurements used and 'Y' indicates the number of measurements permitted.
Attribute:
Attribute_Label: Hf_MEAS_USED
Attribute_Definition:
Number of zircon measurements per sample, out of the permissible measurements (i.e., total analyzed minus excluded), which contribute to the calculation of weighted means of Hafnium isotopes. Brackets that follow are either empty or include the number or numbers of the measurements excluded from calculation. The value 'single grain' indicates one or few measurements were possible for the sample.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Attributes for this data set are 'single grain' and a series of results in the format 'X of Y', where 'X' indicates number of measurements used and 'Y' indicates the number of measurements permitted.
Attribute:
Attribute_Label: TE_MEAS_USED
Attribute_Definition:
Number of zircon measurements per sample, out of the permissible measurements (i.e., total analyzed minus excluded), which contribute to the calculation of medians of trace element compositions. The value 'single grain' indicates one or few measurements were possible for the sample.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Attributes for this data set are 'single grain', and a series of results in the format 'X of Y (med.)', where 'X' indicates number of measurements used and 'Y' indicates the number of measurements permitted, expressed as a median amount.
Attribute:
Attribute_Label: Age_Type
Attribute_Definition:
Method used to calculate the values for each individual analysis that yielded a valid result. "age7corr" indicates a 207Pb-corrected 206Pb/238U age (Ma), for U-Pb ages < 1.4Ga.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: age7corr
Enumerated_Domain_Value_Definition: age7corr = analyses of 207Pb-corrected 206Pb/238U age
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: w_mean_age_Ma
Attribute_Definition:
Weighted mean of 207Pb-corrected 206Pb/238U ages (Ma). Blank cells are present, indicating data was not available to complete this calculation.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 96.88
Range_Domain_Maximum: 117.27
Attribute_Units_of_Measure: Mega-annum, or millions of years before present
Attribute:
Attribute_Label: w_mean_age_Ma_2sigma
Attribute_Definition:
2-sigma (uncertainty) in the weighted mean of 207Pb-corrected 206Pb/238U ages (Ma). Long-term instrument reproducibility is typically higher than analytical uncertainty, approximately 2% of the age. Blank cells are present, indicating data was not available to complete this calculation.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.49
Range_Domain_Maximum: 42.48
Attribute_Units_of_Measure: Mega-annum, or millions of years before present
Attribute:
Attribute_Label: MSWD
Attribute_Definition:
Mean square weighted deviation of ages; blank cells are present to indicate single grain analyses.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.62
Range_Domain_Maximum: 9.33
Attribute:
Attribute_Label: 176Hf_177Hf_ratio
Attribute_Definition: The ratio of 176Hf to 177Hf.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.282442
Range_Domain_Maximum: 0.282723
Attribute:
Attribute_Label: 176Hf_177Hf_ratio_2sigma
Attribute_Definition: 2-sigma (uncertainty) values for the ratio of 176Hf to 177Hf.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.000011
Range_Domain_Maximum: 0.000942
Attribute:
Attribute_Label: 176Lu_177Hf_ratio
Attribute_Definition: The weighted mean ratio of 176Lu to 177Hf.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.000454
Range_Domain_Maximum: 0.003256
Attribute:
Attribute_Label: 176Lu_177Hf_ratio_2sigma
Attribute_Definition:
2-sigma (uncertainty) values for the weighted mean ratio of 176Lu to 177Hf
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.000012
Range_Domain_Maximum: 0.002158
Attribute:
Attribute_Label: eHf
Attribute_Definition:
Epsilon Hf value, assuming a chondritic 176Hf/177Hf value of 0.282772 (Blichert-Toft and Albarede, 1997).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -1.73
Range_Domain_Maximum: -11.67
Attribute:
Attribute_Label: eHf_2sigma
Attribute_Definition:
2-sigma (uncertainty) values for epsilon Hf value, assuming a chondritic 176Hf/177Hf value of 0.282772 (Blichert-Toft and Albarede, 1997).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.39
Range_Domain_Maximum: 33.31
Attribute:
Attribute_Label: 176Hf_177Hf_T
Attribute_Definition:
Age-corrected 176Hf/177Hf ratio, assuming Lutetium-176 decay constant of 1.86x10e-11 (Scherer et al., 2001).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.282435
Range_Domain_Maximum: 0.282719
Attribute:
Attribute_Label: eHf_T
Attribute_Definition:
Age-corrected epsilon Hf value assuming chondritic 176Hf/177Hf ratio of 0.282772 and 176Lu/177Hf ratio of 0.0332 (Blichert-Toft and Albarede, 1997).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -0.08
Range_Domain_Maximum: -9.87
Attribute:
Attribute_Label: T_DM_Hf
Attribute_Definition:
Model age in billions of years before present (Ga) assuming a present-day depleted mantle 176Lu/177Hf and 176Hf/177Hf of 0.0384 and 0.28325 (Griffin et al., 2000).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.77
Range_Domain_Maximum: 1.22
Attribute_Units_of_Measure: (Ga) Giga-annum, or billions of years before present
Attribute:
Attribute_Label: m_Si_ppm
Attribute_Definition: Median silica (Si) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 149200
Range_Domain_Maximum: 165200
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_P_ppm
Attribute_Definition:
Median phosphorous (P) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 12.8
Range_Domain_Maximum: 1210.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Ti_ppm
Attribute_Definition: Median titanium (Ti) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1.05
Range_Domain_Maximum: 16.30
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Sr_ppm
Attribute_Definition:
Median strontium (Sr) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.08
Range_Domain_Maximum: 1.83
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Y_ppm
Attribute_Definition: Median yttrium (Y) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 241
Range_Domain_Maximum: 10390
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Nb_ppm
Attribute_Definition: Median niobium (Nb) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.53
Range_Domain_Maximum: 20.80
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_La_ppm
Attribute_Definition:
Median lanthanum (La) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.031
Range_Domain_Maximum: 32.000
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Ce_ppm
Attribute_Definition: Median cerium (Ce) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 3.3
Range_Domain_Maximum: 381.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Pr_ppm
Attribute_Definition:
Median praseodymium (Pr) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.07
Range_Domain_Maximum: 11.20
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Nd_ppm
Attribute_Definition:
Median neodymium (Nd) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.48
Range_Domain_Maximum: 42.50
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Sm_ppm
Attribute_Definition: Median samarium (Sm) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.73
Range_Domain_Maximum: 44.40
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Eu_ppm
Attribute_Definition: Median europium (Eu) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.30
Range_Domain_Maximum: 13.54
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Gd_ppm
Attribute_Definition:
Median gadolinium (Gd) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 3.6
Range_Domain_Maximum: 277.8
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Tb_ppm
Attribute_Definition:
Median terbium (Tb) concentration, in parts per million (ppm). Blank cells are present.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1.4
Range_Domain_Maximum: 89.3
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Dy_ppm
Attribute_Definition:
Median dysprosium (Dy) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 18.4
Range_Domain_Maximum: 971.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Ho_ppm
Attribute_Definition: Median holmium (Ho) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 6.9
Range_Domain_Maximum: 305.6
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Er_ppm
Attribute_Definition: Median erbium (Er) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 36.3
Range_Domain_Maximum: 1250.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Tm_ppm
Attribute_Definition: Median thulium (Tm) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 9.7
Range_Domain_Maximum: 278.9
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Yb_ppm
Attribute_Definition:
Median ytterbium (Yb) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 92.8
Range_Domain_Maximum: 2510.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Lu_ppm
Attribute_Definition: Median lutetium (Lu) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 19.8
Range_Domain_Maximum: 493.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Hf_ppm
Attribute_Definition: Median hafnium (Hf) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 5942
Range_Domain_Maximum: 11400
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Ta_ppm
Attribute_Definition: Median tantalum (Ta) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.116
Range_Domain_Maximum: 13.110
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_Th_ppm
Attribute_Definition: Median thorium (Th) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 60.2
Range_Domain_Maximum: 15340.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: m_U_ppm
Attribute_Definition: Median uranium (U) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 502
Range_Domain_Maximum: 7880
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: T_C
Attribute_Definition:
Ti-in-zircon thermometer (degrees C), after Ferry and Watson (2007), calculated using median Ti concentrations and assuming SiO2 and TiO2 of 0.7
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 595
Range_Domain_Maximum: 833
Attribute_Units_of_Measure: degrees Celsius
Detailed_Description:
Entity_Type:
Entity_Type_Label: geology_LASS_Geochronolgy_DarbyMtns_DrewesTodd.csv
Entity_Type_Definition:
Table with zircon LASS data, reporting the isotropic concentration of uranium (U) and thorium (Th) measured in individual grains, isotopic ratios of lead and uranium, and the age of each grain interpreted from the isotopic ratios. This table also reports hafnium isotope and concentrations of selected trace elements measured in the same grains. This table contains 606 records and is presented in comma separated value (.csv) format.
Entity_Type_Definition_Source: Author defined
Attribute:
Attribute_Label: Index
Attribute_Definition:
Numeric identifier used for sorting purposes within this table only.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1
Range_Domain_Maximum: 606
Attribute:
Attribute_Label: Sample
Attribute_Definition: Sample number as collected in the field; USGS identifier.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Sample identifier; most labels consisting of the last two digits of the year collected, an abbreviation identifying the collector, and a number and possible alphanumeric suffix. All sample identifiers link to field 'Sample' in table "geology_LASS_SampleSummary_DarbyMtns_AK_Drewes.csv".
Attribute:
Attribute_Label: Mount
Attribute_Definition:
Internal laboratory alphanumeric identifier for a specific sample mount.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Values in this field consist of three letter initials followed by a two-digit number, denoting a specific and repeatable laboratory equipment configuration.
Attribute:
Attribute_Label: Session_Run
Attribute_Definition:
Year and month of analytical session, and Run sequence within that session, when analysis was conducted.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Values in this data set are a concatenation of the calendar year followed by a "/", the number associated with the calendar month, a two-digit number indicating the procedural sequence during the month indicated, the word "_RUN_", and a two-digit number. Multiple runs are indicated in certain cells.
Attribute:
Attribute_Label: Timestamp
Attribute_Definition:
Concatenation of date and time of analysis for individual analysis spot.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 2018-05-14_ 15:34:46
Range_Domain_Maximum: 2018-05-18_ 08:34:54
Attribute_Units_of_Measure: Date Time (YYYY-MM-DD hh:mm:ss) local time
Attribute:
Attribute_Label: Spot_ID
Attribute_Definition:
Internal ID number of individual analysis location, generally the sample name or other laboratory identifier followed by a number for each individual grain.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
The values in this data set are a concatenation of parts of the field 'Sample' or other laboratory identifier, a dash or underscore, and a number indicating a unique location during the procedure.
Attribute:
Attribute_Label: Spot_Size_um
Attribute_Definition: Laser spot size during analyses, in micrometers (um).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 50
Range_Domain_Maximum: 65
Attribute_Units_of_Measure: um (micrometers)
Attribute:
Attribute_Label: Laser_Run_Conditions
Attribute_Definition:
Laser run conditions during analysis; repetition rate (Hz), fluence (%) and output (mJ).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
The attributes in this field are a concatenation of the frequency of the laser in Hz (cycles per second), power setting of the laser in % (percent), and output power setting of the laser in mJ (milliJoules).
Attribute:
Attribute_Label: Method
Attribute_Definition:
Analytical configuration used; "LASS" short for laser-ablation split-stream, indicates simultaneous quadrupole inductively coupled plasma spectrometer (Q-ICPMS) and multi-collector inductively coupled plasma spectrometer (MC-ICP-MS) analyses, measuring U-Th-Pb and trace elements on Q-ICPMS and Hf isotopes on MC-ICP-MS.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: LASS
Enumerated_Domain_Value_Definition: Laser-ablation split-stream analytical configuration
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: U_Pb_x_from_wtmn
Attribute_Definition:
Grains with discordant ages (generally <0.80 or >1.05 concordance; tolerances adjusted to <0.70 and >1.10 for smallest sample populations), calculated analytical age uncertainty in excess of 5%, or U/Th ratios indicating metamorphic origin, or grains interpreted as inherited, that are omitted from calculated weighted mean ages. Blank cells are present.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Blank cells
Enumerated_Domain_Value_Definition: Grain was not omitted from calculation.
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: X
Enumerated_Domain_Value_Definition: Value indicates a grain was omitted from calculations.
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: Hf_x_from_wtmn
Attribute_Definition:
Grains omitted from calculation of Hf isotope characterization for zircon populations. These include all grains excluded from calculated weighted mean ages, plus those with uncertainty in excess of 5%, or obvious outliers, the latter of which are typically associated with particularly small grain to spot size ratios. Blank cells are present.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Blank cells
Enumerated_Domain_Value_Definition: Grain was not omitted from calculation.
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: X
Enumerated_Domain_Value_Definition: Value indicates a grain was omitted from calculations.
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: TE_x_from_median
Attribute_Definition:
Grains omitted from calculation of median trace element composition for zircon populations. These include all grains excluded from weighted mean and Hf isotopes, and zircon grains suspected of containing inclusions imparting non-zircon signal on integration of measured trace elements. Blank cells are present.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Blank cells
Enumerated_Domain_Value_Definition: Grain was not omitted from calculation.
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: X
Enumerated_Domain_Value_Definition: Value indicates a grain was omitted from calculations.
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: Comment_exclude
Attribute_Definition:
Shorthand description for why a grain was considered not permissible for deriving representative values for any one of the three datasets (U/Pb age, Hf isotope, trace elements); for more details see the document: "Supplemental_Info_Analytical_Methods_UCSB_LASS.pdf", included in this data package. Blank cells are present.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
The values in this data set are general remarks denoting rationale for exclusion. This is a free text field.
Attribute:
Attribute_Label: U_ppm
Attribute_Definition: The concentration of uranium (U), in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 109.8
Range_Domain_Maximum: 697000.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Th_ppm
Attribute_Definition: The concentration of thorium (Th), in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 12.0
Range_Domain_Maximum: 5280000.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: 207Pb_235U_ratio
Attribute_Definition: The ratio of 207Pb to 235U.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.0965
Range_Domain_Maximum: 6.8000
Attribute:
Attribute_Label: 207Pb_235U_ratio_2sigma
Attribute_Definition: 2-sigma (absolute uncertainty) on the ratio of 207Pb to 235U.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.0025
Range_Domain_Maximum: 3.1029
Attribute:
Attribute_Label: 206Pb_238U_ratio
Attribute_Definition: The ratio of 206Pb to 238U.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.0146
Range_Domain_Maximum: 0.2130
Attribute:
Attribute_Label: 206Pb_238U_ratio_2sigma
Attribute_Definition: 2-sigma (absolute uncertainty) on the ratio of 206Pb to 238U.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.0004
Range_Domain_Maximum: 0.0260
Attribute:
Attribute_Label: rho_6_38vs7_35
Attribute_Definition:
Error correlation coefficient between 206Pb/238U and 207Pb/235U, for generating concordia plot.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -0.58
Range_Domain_Maximum: 1.00
Attribute:
Attribute_Label: 238U_206Pb_ratio
Attribute_Definition: The ratio of 238U to 206Pb.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 4.7
Range_Domain_Maximum: 68.4
Attribute:
Attribute_Label: 238U_206Pb_ratio_2sigma
Attribute_Definition: 2-sigma (uncertainty) on the ratio of 238U to 206Pb.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.13
Range_Domain_Maximum: 11.43
Attribute:
Attribute_Label: 207Pb_206Pb_ratio
Attribute_Definition: The ratio of 207Pb to 206Pb.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.046
Range_Domain_Maximum: 0.550
Attribute:
Attribute_Label: 207Pb_206Pb_ratio_2sigma
Attribute_Definition: 2-sigma (uncertainty) on the ratio of 207Pb to 206Pb.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.001
Range_Domain_Maximum: 0.111
Attribute:
Attribute_Label: rho_38_6vs7_6
Attribute_Definition:
Error correlation coefficient between 238U/206Pb and 207Pb/206Pb, for generating concordia plot.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -0.99
Range_Domain_Maximum: 0.84
Attribute:
Attribute_Label: 208Pb_232Th_ratio
Attribute_Definition: The ratio of 208Pb to 232Th.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -34000.00
Range_Domain_Maximum: 49.00
Attribute:
Attribute_Label: 208Pb_232Th_ratio_2sigma
Attribute_Definition: 2-sigma (uncertainty) on the ratio of 208Pb to 232Th.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -13017.78
Range_Domain_Maximum: 19.03
Attribute:
Attribute_Label: 206Pb_208Pb_ratio
Attribute_Definition: The ratio of 206Pb to 208Pb.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.21
Range_Domain_Maximum: 263.00
Attribute:
Attribute_Label: 206Pb_208Pb_ratio_2sigma
Attribute_Definition: 2-sigma (uncertainty) values for the ratio of 206Pb to 208Pb.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.01
Range_Domain_Maximum: 31.00
Attribute:
Attribute_Label: 206Pb_238U_Age_Ma
Attribute_Definition: Age (Ma) calculated from 206Pb/238U.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 93.63
Range_Domain_Maximum: 1244.78
Attribute_Units_of_Measure: Mega-annum, or millions of years before present
Attribute:
Attribute_Label: 206Pb_238U_Age_Ma_2sigma
Attribute_Definition: The 2-sigma (uncertainty) in the 206Pb/238U age (Ma).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 3.05
Range_Domain_Maximum: 162.34
Attribute_Units_of_Measure: Mega-annum, or millions of years before present
Attribute:
Attribute_Label: 207Pb_206Pb_Age_Ma
Attribute_Definition: Age (Ma) calculated from 207Pb/206Pb.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 8.07
Range_Domain_Maximum: 4381.15
Attribute_Units_of_Measure: Mega-annum, or millions of years before present
Attribute:
Attribute_Label: 207Pb_206Pb_Age_Ma_2sigma
Attribute_Definition: The 2-sigma (uncertainty) in the 207Pb/206Pb age (Ma).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.31
Range_Domain_Maximum: 1080.67
Attribute_Units_of_Measure: Mega-annum, or millions of years before present
Attribute:
Attribute_Label: Concordance
Attribute_Definition:
Ratio of age determined using 206Pb/238U versus age determined using 207Pb/235U.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.18
Range_Domain_Maximum: 1.04
Attribute:
Attribute_Label: Age_Type
Attribute_Definition:
Method used to calculate the values for each individual analysis that yielded a valid result. "age7corr" indicates a 207Pb-corrected 206Pb/238U age (Ma), for U-Pb ages < 1.4Ga.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: age7corr
Enumerated_Domain_Value_Definition: 207Pb-corrected 206Pb/238U age (Ma), for U-Pb ages < 1.4Ga
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: Preferred_Age
Attribute_Definition:
Preferred grain age for calculation of sample age (in millions of years, or Ma), selected from one of two following fields containing corrected ages for each grain: 207Pb-corrected 206Pb/238U age (Ma) for U-Pb ages < 1.4Ga; For U-Pb ages > 1.4Ga, or 207Pb/206Pb for U-Pb ages >1.4Ga.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 87.26
Range_Domain_Maximum: 1239.41
Attribute_Units_of_Measure: Mega-annum, or millions of years before present
Attribute:
Attribute_Label: Preferred_Age_2sigma
Attribute_Definition:
Uncertainty (2-sigma) on preferred grain age (in millions of years, or Ma).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 2.24
Range_Domain_Maximum: 95.57
Attribute_Units_of_Measure: Mega-annum, or millions of years before present
Attribute:
Attribute_Label: 176Hf_177Hf_ratio
Attribute_Definition:
The ratio of 176Hf to 177Hf. Blank cells are present, indicating no data was measured.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.28212
Range_Domain_Maximum: 0.28307
Attribute:
Attribute_Label: 176Hf_177Hf_ratio_2sigma
Attribute_Definition:
Uncertainty (2-sigma) values for the ratio of 176Hf to 177Hf. Blank cells are present, indicating no data was measured.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.000051
Range_Domain_Maximum: 0.000340
Attribute:
Attribute_Label: 176Lu_177Hf_ratio
Attribute_Definition:
The ratio of 176Lu to 177Hf. Blank cells are present, indicating no data was measured.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.000132
Range_Domain_Maximum: 0.015010
Attribute:
Attribute_Label: 176Lu_177Hf_ratio_2sigma
Attribute_Definition:
Uncertainty (2-sigma) values for the ratio of 176Lu to 177Hf. Blank cells are present, indicating no data was measured.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.000001
Range_Domain_Maximum: 0.000220
Attribute:
Attribute_Label: 178Hf_177Hf_ratio
Attribute_Definition:
The ratio of 178Hf to 177Hf. Blank cells are present, indicating no data was measured.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1.46703
Range_Domain_Maximum: 1.46740
Attribute:
Attribute_Label: 178Hf_177Hf_ratio_2sigma
Attribute_Definition:
2-sigma (uncertainty) values for the ratio of 178Hf to 177Hf. Blank cells are present, indicating no data was measured, and some cells contain the value "-9999.000000", indicating failure of measurement equipment to resolve the data.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.00009
Range_Domain_Maximum: 0.00016
Attribute:
Attribute_Label: eHf
Attribute_Definition:
Epsilon Hf value, assuming a chondritic 176Hf/177Hf value of 0.282772 (Blichert-Toft and Albarede, 1997). Blank cells are present, indicating no result was calculated.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -23.06
Range_Domain_Maximum: 10.54
Attribute:
Attribute_Label: eHf_2sigma
Attribute_Definition:
2-sigma (uncertainty) values for epsilon Hf value, assuming a chondritic 176Hf/177Hf value of 0.282772 (Blichert-Toft and Albarede, 1997). Blank cells are present, indicating no result was calculated.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1.80
Range_Domain_Maximum: 12.02
Attribute:
Attribute_Label: 176Hf_177Hf_T
Attribute_Definition:
Age-corrected 176Hf/177Hf ratio, assuming Lutetium-176 decay constant of 1.86x10e-11 (Scherer et al., 2001); not calculated if discordant or no same-grain age measurement.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.282097
Range_Domain_Maximum: 0.283053
Attribute:
Attribute_Label: eHf_T
Attribute_Definition:
Age-corrected epsilon Hf value assuming chondritic 176Hf/177Hf ratio of 0.282772 and 176Lu/177Hf ratio of 0.0332 (Blichert-Toft and Albarede, 1997); not calculated if discordant or no same-grain age measurement.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -13.58
Range_Domain_Maximum: 11.74
Attribute:
Attribute_Label: T_DM_Hf
Attribute_Definition:
Model age in billions of years before present (Ga) assuming a present-day depleted mantle 176Lu/177Hf and 176Hf/177Hf of 0.0384 and 0.28325 (Griffin et al., 2000). Blank cells are present, indicating no result was calculated.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 1.60
Attribute_Units_of_Measure: Giga-annum, or billions of years before present
Attribute:
Attribute_Label: Zr_cps
Attribute_Definition:
Raw, uncalibrated signal intensity of zirconium (Zr), measured in counts per second (cps). Provided for informational purposes only.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 6.29E+04
Range_Domain_Maximum: 6.62E+08
Attribute_Units_of_Measure: cps (counts per second)
Attribute:
Attribute_Label: Si_ppm
Attribute_Definition: Silica (Si) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1.44E+05
Range_Domain_Maximum: 6.02E+08
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: P_ppm
Attribute_Definition: Phosphorous (P) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 9.2
Range_Domain_Maximum: 257000.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Ti_ppm
Attribute_Definition: Titanium (Ti) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.47
Range_Domain_Maximum: 636000000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Sr_ppm
Attribute_Definition: Strontium (Sr) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.03
Range_Domain_Maximum: 1900000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Y_ppm
Attribute_Definition: Yttrium (Y) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 67.6
Range_Domain_Maximum: 1740000.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Nb_ppm
Attribute_Definition: Niobium (Nb) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.43
Range_Domain_Maximum: 5650000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: La_ppm
Attribute_Definition:
Lanthanum (La) concentration, in parts per million (ppm). Blank cells are present.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.003
Range_Domain_Maximum: 5790000.000
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Ce_ppm
Attribute_Definition: Cerium (Ce) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 2.12
Range_Domain_Maximum: 8850000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Pr_ppm
Attribute_Definition: Praseodymium (Pr) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.01
Range_Domain_Maximum: 2110000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Nd_ppm
Attribute_Definition: Neodymium (Nd) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.07
Range_Domain_Maximum: 4900000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Sm_ppm
Attribute_Definition: Samarium (Sm) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.09
Range_Domain_Maximum: 1860000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Eu_ppm
Attribute_Definition: Europium (Eu) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.07
Range_Domain_Maximum: 383000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Gd_ppm
Attribute_Definition: Gadolinium (Gd) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.76
Range_Domain_Maximum: 2570000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Tb_ppm
Attribute_Definition: Terbium (Tb) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.32
Range_Domain_Maximum: 540000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Dy_ppm
Attribute_Definition: Dysprosium (Dy) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 4.87
Range_Domain_Maximum: 3700000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Ho_ppm
Attribute_Definition: Holmium (Ho) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1.97
Range_Domain_Maximum: 690000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Er_ppm
Attribute_Definition: Erbium (Er) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 10.36
Range_Domain_Maximum: 1860000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Tm_ppm
Attribute_Definition: Thulium (Tm) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 2.92
Range_Domain_Maximum: 260000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Yb_ppm
Attribute_Definition: Ytterbium (Yb) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 28.2
Range_Domain_Maximum: 1390000.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Lu_ppm
Attribute_Definition: Lutetium (Lu) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 5.8
Range_Domain_Maximum: 194000.0
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Hf_ppm
Attribute_Definition: Hafnium (Hf) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 5000
Range_Domain_Maximum: 50400
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: Ta_ppm
Attribute_Definition: Tantalum (Ta) concentration, in parts per million (ppm).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.08
Range_Domain_Maximum: 3650000.00
Attribute_Units_of_Measure: ppm (parts per million)
Attribute:
Attribute_Label: T_C
Attribute_Definition:
Ti-in-zircon thermometer (degrees C), after Ferry and Watson (2007), assuming SiO2 and TiO2 of 0.7. Blank cells are present, indicating no calculation for grains excluded from main populations.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 555
Range_Domain_Maximum: 938
Attribute_Units_of_Measure: degrees Celsius
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey, Alaska Science Center
Contact_Address:
Address_Type: Mailing and Physical
Address: 4210 University Drive
City: Anchorage
State_or_Province: Alaska
Postal_Code: 99508
Country: USA
Contact_Voice_Telephone: 907-786-7000
Contact_Electronic_Mail_Address: ascweb@usgs.gov
Resource_Description:
The U.S. Geological Survey, Alaska Science Center is the authoritative source and distributor of these data.
Distribution_Liability:
Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data for other purposes or on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: CSV
Format_Information_Content:
Data are distributed in a Zip package containing data in CSV and PDF format and FGDC metadata in XML and HTML formats.
File_Decompression_Technique:
Compression applied by the 7-Zip utility using the default compression [5]. The Zip package can be decompressed and unpacked by open source or commercially available unzip tools.
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: https://doi.org/10.5066/P9JKR2J6
Fees: None
Metadata_Reference_Information:
Metadata_Date: 20230124
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey, Alaska Science Center
Contact_Address:
Address_Type: Mailing and Physical
Address: 4210 University Drive
City: Anchorage
State_or_Province: Alaska
Postal_Code: 99508
Country: USA
Contact_Voice_Telephone: 907-786-7000
Contact_Electronic_Mail_Address: ascweb@usgs.gov
Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata (CSDGM)
Metadata_Standard_Version: FGDC-STD-001-1998
Generated by mp version 2.9.52 on Tue Jan 24 21:29:29 2023