U-Pb Isotopic Data and Ages of Titanite and Detrital Zircon from Selected Rocks from the Western Alaska Range, Alaska

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: Jones III, J.V. (ORCID: 0000-0002-6602-5935)
Originator: Box, S.E. (ORCID: 0000-0002-5268-8375)
Originator: Karl, S. (ORCID: 0000-0003-2038-5342)
Originator: Bradley, D.C. (ORCID: 0000-0001-9116-5289)
Originator: Haeussler, P.J. (ORCID: 0000-0002-1503-6247)
Originator: O'Sullivan, P. (ORCID: 0000-0002-7247-5107)
Publication_Date: 20200615
Title:
U-Pb Isotopic Data and Ages of Titanite and Detrital Zircon from Selected Rocks from the Western Alaska Range, 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: Jones III, J.V., Box, S.E., Karl, S.M., Bradley, D.C., Haeussler, P.J., and O'Sullivan, P., 2020, U-Pb isotopic data and ages of titanite and detrital zircon from selected rocks from the western Alaska Range, Alaska: U.S. Geological Survey data release, https://doi.org/10.5066/P9JV5LM9.
Online_Linkage: https://doi.org/10.5066/P9JV5LM9
Larger_Work_Citation:
Citation_Information:
Originator: Box, S.E. (ORCID: 0000-0002-5268-8375)
Originator: Karl, S. (ORCID: 0000-0003-2038-5342)
Originator: Jones III, J.V. (ORCID: 0000-0002-6602-5935)
Originator: Bradley, D.C. (ORCID: 0000-0001-9116-5289)
Originator: Haeussler, P.J. (ORCID: 0000-0002-1503-6247)
Originator: O'Sullivan, P. (ORCID: 0000-0002-7247-5107)
Publication_Date: 2019
Title:
Detrital Zircon Geochronology along a Structural Transect across the Kahiltna Assemblage in the Western Alaska Range: Implications for Emplacement of the Alexander-Wrangellia-Peninsular Terrane against North America
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Geosphere
Issue_Identification: vol. 15
Other_Citation_Details:
Suggested citation: Box, S.E., Karl, S.M., Jones III, J.V., Bradley, D.C., Haeussler, P.J., and O'Sullivan, P.B., 2019, Detrital zircon geochronology along a structural transect across the Kahiltna assemblage in the western Alaska Range: Implications for emplacement of the Alexander-Wrangellia-Peninsular terrane against North America: Geosphere, vol. 15, 35 pages. https://doi.org/10.1130/GES02060.1
Online_Linkage: https://doi.org/10.1130/GES02060.1
Description:
Abstract:
This data set contains U-Pb isotopic data and associated ages of titanite from one sample and detrital zircon grains from 33 sedimentary and metasedimentary rocks collected from the western Alaska Range in south-central Alaska. The samples were collected as part of geological mapping and research conducted between 2010 and 2014 and funded by the Mineral Resources Program of the U.S. Geological Survey. Titanite was separated by Apatite to Zircon, Inc. (A2Z) and analyzed by USGS research staff at the Stanford-US Geological Survey (USGS) Sensitive High Resolution Ion Microprobe with Reverse-Geometry (SHRIMP-RG) at Stanford University. Detrital zircon grains from each of the 33 samples were separated and analyzed by Apatite to Zircon, Inc. (A2Z) and GeoSep Services (GSS) laboratories between 2011 and 2014, using laser-ablation-inductively-coupled-plasma-mass spectrometry (LA-ICP-MS) techniques described in the supplemental file. The data tables report the concentration of the radioactive elements uranium (U) and thorium (Th) measured in each grain, corrected ratios of two isotopes of lead (207Pb and 206Pb) to two isotopes of uranium (235U and 238U), and the geologic age of each grain calculated from the isotopic ratios. The titanite data table also reports concentrations of selected trace elements measured in each grain.
Purpose:
U-Pb isotopic ages of titanite in igneous rocks aid in the interpretation of age of igneous crystallization and/or metamorphism of an igneous protolith. U-Pb ages of detrital zircon grains aid in the interpretation of possible sediment sources and pathways during deposition. The youngest detrital zircon ages in any single sample also provides information about the maximum possible depositional age of the sediment and, therefore, the geologic unit that contains it. Comparison of detrital zircon age populations between samples provides a critical test of local to regional correlations of geologic units and aids in the reconstruction of geologic histories of large regions. In this study, the data were used to understand the geologic history of part of the Kahiltna assemblage, a composite succession of Mesozoic clastic sedimentary rocks exposed throughout south-central Alaska. Detailed interpretations of the data and a discussion of the results and implications of the study can be found in the journal Geosphere (Box et al, 2019).
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2020
Currentness_Reference: publication date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -154.36
East_Bounding_Coordinate: -151.45
North_Bounding_Coordinate: 62.57
South_Bounding_Coordinate: 61.28
Keywords:
Theme:
Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:ASC272
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: geoscientificInformation
Theme:
Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: geology
Theme_Keyword: geochronology
Theme_Keyword: uranium-lead analysis
Theme_Keyword: igneous rocks
Theme_Keyword: sedimentary rocks
Theme:
Theme_Keyword_Thesaurus: NASA GCMD Earth Science Keywords Thesaurus
Theme_Keyword: earth science
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: U-Pb
Theme_Keyword: detrital zircon
Theme_Keyword: titanite
Place:
Place_Keyword_Thesaurus: USGS Geographic Names Information System (GNIS)
Place_Keyword: Alaska
Place_Keyword: Alaska Range
Access_Constraints: None
Use_Constraints:
None. Users are advised to read the metadata thoroughly to understand appropriate use and data limitations.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey, Alaska Science Center
Contact_Person: James V. Jones
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing and physical address
Address: 4210 University Drive
City: Anchorage
State_or_Province: Alaska
Postal_Code: 99508-4626
Country: U.S.A.
Contact_Voice_Telephone: 907-786-7000
Contact_Electronic_Mail_Address: ascweb@usgs.gov
Cross_Reference:
Citation_Information:
Originator: Jones III, J.V. (ORCID: 0000-0002-6602-5935)
Publication_Date: 2009
Title: Western Alaska Range Metallogeny and Tectonics
Geospatial_Data_Presentation_Form: website
Series_Information:
Series_Name: Alaska Science Portal
Issue_Identification: 302
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=302
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The zircon samples were run with zircon reference materials, and the titanite sample was run with titanite reference materials. The reference materials were analyzed until fractionation was stable and the variance in the measured 206Pb/238U and 207Pb/206Pb ratios was at or near 1 percent. Reference materials were subsequently analyzed together with unknowns to monitor fractionation throughout the analytical session. All measured isotopic ratios are reported with associated analytical uncertainty.
Logical_Consistency_Report: No unexpected values are found in these data.
Completeness_Report: This data set is complete; no data were omitted.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Horizontal position was measured using hand-held GPS units with positional accuracy of 3 meters or less.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Apatite to Zircon, Inc.
Publication_Date: 2018
Title: Detrital Zircon Analytical Methods
Publication_Information:
Publication_Place: Moscow, Idaho
Publisher: Apatite to Zircon, Inc. GeoSep Services
Other_Citation_Details:
This is a supplemental document included in this data release. The file name is Supplemental_Info_Analytical_Methods_A2Z.pdf
Type_of_Source_Media: pdf file
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2018
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: Supplemental Info Analytical Methods A2Z
Source_Contribution:
Provides detailed description of laboratory methods and data modeling for U-Pb geochronology
Source_Information:
Source_Citation:
Citation_Information:
Originator: Stanford-USGS SHRIMP-RG Laboratory
Publication_Date: 2019
Title:
Titanite U-Pb geochronology and trace element analytical methods using Stanford-USGS SHRIMP-RG
Publication_Information:
Publication_Place: Palo Alto, California
Publisher: Stanford-USGS SHRIMP-RG laboratory
Other_Citation_Details:
This is a supplemental document included in this data release. The file name is Supplemental_Info_Analytical_Methods_StanfordUSGSSHRIMPRG.pdf.
Type_of_Source_Media: pdf file
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2019
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: SHRIMP-RG Methods
Source_Contribution:
Provides detailed descriptions of laboratory methods and data modeling for titanite U-Pb geochronology.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Box, S.E. (ORCID: 0000-0002-5268-8375)
Originator: Karl, S. (ORCID: 0000-0003-2038-5342)
Originator: Jones III, J.V. (ORCID: 0000-0002-6602-5935)
Originator: Bradley, D.C. (ORCID: 0000-0001-9116-5289)
Originator: Haeussler, P.J. (ORCID: 0000-0002-1503-6247)
Originator: O'Sullivan, P. (ORCID: 0000-0002-7247-5107)
Publication_Date: 2019
Title:
Detrital Zircon Geochronology along a Structural Transect across the Kahiltna Assemblage in the Western Alaska Range: Implications for Emplacement of the Alexander-Wrangellia-Peninsular Terrane against North America
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Geosphere
Issue_Identification: vol. 15
Other_Citation_Details:
Suggested citation: Box, S.E., Karl, S.M., Jones III, J.V., Bradley, D.C., Haeussler, P.J., and O'Sullivan, P.B., 2019, Detrital zircon geochronology along a structural transect across the Kahiltna assemblage in the western Alaska Range: Implications for emplacement of the Alexander-Wrangellia-Peninsular terrane against North America: Geosphere, vol. 15, 35 pages. https://doi.org/10.1130/GES02060.1
Online_Linkage: https://doi.org/10.1130/GES02060.1
Type_of_Source_Media: journal article
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2019
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: Box et al, 2019
Source_Contribution:
Provides detailed interpretations of the data and a discussion of the results and implications of the study.
Process_Step:
Process_Description:
For the detrital zircon samples, mineral separation procedures for zircons used lithium polytungstate and a centrifuge. Zircon grains were mounted in epoxy wafers and then ground down to expose internal grain surfaces, and then polished. Isotopic analyses were performed with either a new Wave UP-213 or New Wave YAG 213 laser ablation system in line with a Finnigan Element2 magnetic sector, inductively coupled plasma, mass spectrometer (ICP-MS) at Washington State University GeoAnalytical Laboratory in Pullman, Washington. Detailed analytical procedures are described in the accompanying document, Supplemental_Info_Analytical_Methods_A2Z.pdf.
Source_Used_Citation_Abbreviation: Supplemental Info Analytical Methods A2Z
Process_Date: 2014
Process_Step:
Process_Description:
Titanite 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 internal grain surfaces, polished, and imaged using back-scattered electron (BSE) imaging on a JEOL 5600 SEM to identify internal structure. Titanite U-Pb ages were obtained with the Stanford-U.S. Geological Survey (USGS) Sensitive High Resolution Ion Microprobe with Reverse-Geometry (SHRIMP-RG) at Stanford University. Detailed analytical procedures are described in the accompanying document, Supplemental_Info_Analytical_Methods_StanfordUSGSSHRIMPRG.pdf.
Source_Used_Citation_Abbreviation: SHRIMP-RG Methods
Process_Date: 2014
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
Ellipsoid_Name: GRS 1980
Semi-major_Axis: 6378137
Denominator_of_Flattening_Ratio: 298.257222101
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: GEOCHRONOLOGY_TITANITE_DATA.csv
Entity_Type_Definition:
Table of U-Pb titanite SHRIMP-RG data, reporting the concentration of the radioactive elements uranium (U) and thorium (Th) measured in individual grains, corrected ratios of lead and uranium isotopes, and the geologic age of each grain calculated from the isotope ratios. The table also reports concentrations of selected trace elements measured in the same grains. The table is presented in comma separated value (CSV) format.
Entity_Type_Definition_Source: Author defined
Attribute:
Attribute_Label: Sample
Attribute_Definition:
Sample number assigned when sample was collected in the field. The value is unique to a sample but is repeated many times is this table because many individual titanite grains from a single sample are analyzed. The attribute 'spot' is a unique primary key for this data table. Descriptive and locational information about the sample is in table GEOCHRONOLOGY_SAMPLE_SUMMARY.csv, and may be linked through attribute Sample.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Unique sample identifier consisting of the last two digits of the year, abbreviation identifying the collector, and a number and possible suffix.
Attribute:
Attribute_Label: Mineral
Attribute_Definition: Mineral analyzed
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain: mineral name
Attribute:
Attribute_Label: Mount
Attribute_Definition: Internal laboratory ID number for sample mount
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain: alphanumeric code assigned by the laboratory
Attribute:
Attribute_Label: Analysis_date
Attribute_Definition: Month and year when analysis was conducted.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain: Date presented as 'month year'.
Attribute:
Attribute_Label: Standard
Attribute_Definition: Age reference material used on mount
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Titanite standard BLR which has standard deviations (2 sigma) of about +/- 3% for Hf, +/- 5-10% for Y and the heavy rare earth elements (HREE), +/- 10-15% for the light rare earth elements (LREE), and up to +/- 40% for La. U-Pb ages were calculated relative to the BLR titanite standard (1047 Ma).
Attribute:
Attribute_Label: Standard_Age
Attribute_Definition:
Assumed age of age reference material for data reduction, in million years before present (mega-annum).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain: Assumed age of standard BLR is 1047 Ma.
Attribute:
Attribute_Label: Conc_Std
Attribute_Definition:
Reference material used to calculate trace element concentrations in unknowns.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Titanite reference material BLR has a well calibrated trace element composition with standard deviations (2 sigma) of about +/- 3% for Hf, +/- 5-10% for Y and the heavy rare earth elements (HREE), +/- 10-15% for the light rare earth elements (LREE), and up to +/- 40% for La.
Attribute:
Attribute_Label: Spot
Attribute_Definition:
Internal ID number of individual analysis spot. This attribute identifies a unique sample analysis in this table.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Alphanumeric code assigned by the analyst. The first number after the sample name indicates the unique grain from an individual sample. The second number indicates the unique spot for each individual grain.
Attribute:
Attribute_Label: U_conc_ppm
Attribute_Definition: Uranium concentration, in parts per million (ppm)
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 3
Range_Domain_Maximum: 157
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Th_conc_ppm
Attribute_Definition: Thorium concentration, in parts per million (ppm)
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 16
Range_Domain_Maximum: 479
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: comm_206Pb
Attribute_Definition: 207Pb corrected common 206Pb, in percent
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.04
Range_Domain_Maximum: 2
Attribute_Units_of_Measure: percent
Attribute:
Attribute_Label: 238U_over_206Pb
Attribute_Definition: Total ratio of 238U to 206Pb
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 36
Range_Domain_Maximum: 64
Attribute:
Attribute_Label: 238U_over_206Pb_Unc
Attribute_Definition: Uncertainty on total ratio of 238U to 206Pb, in percent
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1.6
Range_Domain_Maximum: 6.3
Attribute_Units_of_Measure: percent
Attribute:
Attribute_Label: 207Pb_over_206Pb
Attribute_Definition: Total ratio of 207Pb to 206Pb
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.068
Range_Domain_Maximum: 0.397
Attribute:
Attribute_Label: 207Pb_over_206Pb_Unc
Attribute_Definition: Uncertainty on total ratio of 207Pb to 206Pb, in percent
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 4
Range_Domain_Maximum: 10.6
Attribute_Units_of_Measure: percent
Attribute:
Attribute_Label: 204Pbcorr_238U_over_206Pb
Attribute_Definition: 204Pb-corrected ratio of 238U to 206Pb
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 53
Range_Domain_Maximum: 71
Attribute:
Attribute_Label: 204Pbcorr_238U_over_206Pb_Unc
Attribute_Definition:
Uncertainty on 204Pb-corrected ratio of 238U to 206Pb, in percent
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1
Range_Domain_Maximum: 30
Attribute:
Attribute_Label: 204Pbcorr_207Pb_over_206Pb
Attribute_Definition: 204Pb-corrected ratio of 207Pb to 206Pb
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.01
Range_Domain_Maximum: 0.12
Attribute:
Attribute_Label: 204Pbcorr_207Pb_over_206Pb_Unc
Attribute_Definition:
Uncertainty on 204Pb-corrected ratio of 207Pb to 206Pb, in percent
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 14
Range_Domain_Maximum: 396
Attribute:
Attribute_Label: 204Pbcorr_207Pb_over_235U
Attribute_Definition: 204Pb-corrected ratio of 207Pb to 235U
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.02
Range_Domain_Maximum: 0.33
Attribute:
Attribute_Label: 204Pbcorr_207Pb_over_235U_Unc
Attribute_Definition:
Uncertainty on 204Pb-corrected ratio of 207Pb to 235U, in percent
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 14
Range_Domain_Maximum: 396
Attribute_Units_of_Measure: percent
Attribute:
Attribute_Label: 204Pbcorr_206Pb_over_238U
Attribute_Definition: 204Pb-corrected ratio of 206Pb to 238U
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.01
Range_Domain_Maximum: 0.01
Attribute:
Attribute_Label: 204Pbcorr_206Pb_over_238U_Unc
Attribute_Definition:
Uncertainty on 204Pb-corrected ratio of 206Pb to 238U, in percent
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1
Range_Domain_Maximum: 30
Attribute_Units_of_Measure: percent
Attribute:
Attribute_Label: error_correlation
Attribute_Definition: Error correlation for generating concordia plot
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.01
Range_Domain_Maximum: 0.18
Attribute:
Attribute_Label: 207Pbcorr_206Pb_over_238U_Age
Attribute_Definition:
207Pb-corrected ratio of 206Pb/238U age, in millions of years before present (mega-annum)
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 86.4
Range_Domain_Maximum: 107.9
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 207Pbcorr_206Pb_over_238U_Age_Unc
Attribute_Definition:
One-sigma uncertainty on 207Pb-corrected 206Pb/238U age, in millions of years before present (mega-annum)
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1.5
Range_Domain_Maximum: 10
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 204Pbcorr_207Pb_over_206Pb_Age
Attribute_Definition:
204Pb-corrected 207Pb/206Pb age, in millions of years before present (mega-annum)
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -960.3
Range_Domain_Maximum: 2077.6
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 204Pbcorr_207Pb_over_206Pb_Age_Unc
Attribute_Definition:
One-sigma uncertainty on 204Pb-corrected 207Pb/206Pb age, in millions of years before present (mega-annum)
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 4294
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: Preferred_SHRIMP_Age
Attribute_Definition:
Values are the preferred age (in millions of years, Ma) selected from one of two following fields containing corrected ages for each grain: 207Pb-corr_206Pb_over_238U_Age or 204Pb_corr_207Pb_over_206Pb_Age.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 86.4
Range_Domain_Maximum: 107.9
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: Preferred_SHRIMP_Unc
Attribute_Definition:
Values are 2-sigma uncertainty (in millions of years, Ma) greater or less than the preferred age.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1.5
Range_Domain_Maximum: 10
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: Preferred_SHRIMP_Age_Type
Attribute_Definition:
Correction method used to calculate the values in the Preferred_SHRIMP_Age field for each individual analysis that yielded a valid result.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
207Pb-corr_206Pb_over_238U_Age is the only method for this data set
Attribute:
Attribute_Label: Interpreted_Age_Included
Attribute_Definition:
Indication of whether or not the grain was used in calculating values in the INTERPRETED_AGE_MA field in table GEOCHRONOLOGY_SAMPLE_SUMMARY.csv.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain: yes or no
Attribute:
Attribute_Label: percent_concordant
Attribute_Definition:
Percent agreement of 206Pb/238U age and 207Pb/206Pb, which also corresponds to distance the data point and its associated uncertainty plot below the concordia curve. Values greater than 100% plot above the concordia curve.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 113
Attribute_Units_of_Measure: percent
Attribute:
Attribute_Label: Y
Attribute_Definition: Yttrium concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 102
Range_Domain_Maximum: 3778
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Nb
Attribute_Definition: Niobium concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 36
Range_Domain_Maximum: 2251
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: La
Attribute_Definition: Lanthanum concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 70
Range_Domain_Maximum: 1925
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Ce
Attribute_Definition: Cerium concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 155
Range_Domain_Maximum: 6182
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Pr
Attribute_Definition: Praseodymium concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 20
Range_Domain_Maximum: 849
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Nd
Attribute_Definition: Neodymium concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 99
Range_Domain_Maximum: 3819
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Sm
Attribute_Definition: Samarium concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 25
Range_Domain_Maximum: 829
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Eu
Attribute_Definition: Europium concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 8
Range_Domain_Maximum: 153
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Gd
Attribute_Definition: Gadolinium concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 23
Range_Domain_Maximum: 747
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Dy
Attribute_Definition: Dysprosium concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 17
Range_Domain_Maximum: 610
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Yb
Attribute_Definition: Ytterbium concentration in parts per million
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 14
Range_Domain_Maximum: 328
Attribute_Units_of_Measure: parts per million (ppm)
Detailed_Description:
Entity_Type:
Entity_Type_Label: GEOCHRONOLOGY_DETRITALZIRCON_DATA.csv
Entity_Type_Definition:
Table of U-Pb detrital zircon LA-ICP-MS data, reporting the concentration of the radioactive elements uranium (U) and thorium (Th) measured in each grain, corrected ratios lead (Pb) and uranium (U), and the geologic age of each grain calculated from isotope ratios. The table is presented in comma separated value (CSV) format.
Entity_Type_Definition_Source: Author defined
Attribute:
Attribute_Label: USGS_Sample_Number
Attribute_Definition:
Sample number assigned when sample was collected in the field. The value is unique to a sample but is repeated many times in this table because many individual zircon grains from a single sample are analyzed. Attribute Analysis_Name identifies a unique grain analysis relative to each sample. Descriptive and locational information about the sample is in table GEOCHRONOLOGY_SAMPLE_SUMMARY.csv, and may be linked through attribute Sample.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Unique sample identifier consisting of the last two digits of the year collected, abbreviation identifying the collector, and a number and possible suffix. Collector abbreviations include: AD (J. Dumoulin), AJJ (J.V. Jones), ALR (R. Lease), AMB (Adrian Bender), KS (Karri Sicard), SB (S. Box), SK (S. Karl), WA (Garth Graham).
Attribute:
Attribute_Label: LAB_Sample_NUMBER
Attribute_Definition:
Lab sample identification assigned by A2Z. One to one correspondence to USGS_Sample_Number
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain: Numeric code assigned by the A2Z laboratory.
Attribute:
Attribute_Label: Mineral
Attribute_Definition: Material analyzed
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: DZ
Enumerated_Domain_Value_Definition: detrital zircon
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: Analysis_Name
Attribute_Definition:
Lab sample is a unique identification assigned by A2Z laboratory for an individual analysis.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
An alpha-numeric code including a variation of the LAB_Sample_NUMBER.
Attribute:
Attribute_Label: U_conc_ppm
Attribute_Definition: Concentration of uranium (U) in parts per million (ppm)
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1
Range_Domain_Maximum: 5432
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: Th_conc_ppm
Attribute_Definition: Concentration of thorium (Th) in parts per million (ppm)
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 10138
Attribute_Units_of_Measure: parts per million (ppm)
Attribute:
Attribute_Label: U_Th_ratio
Attribute_Definition:
The ratio of the concentration of uranium (U) to the concentration of thorium (Th).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.3
Range_Domain_Maximum: 1431.6
Attribute_Units_of_Measure: unit-less value
Attribute:
Attribute_Label: 207Pb_235U_Ratio
Attribute_Definition:
The ratio of lead (Pb, isotope 207) to uranium (U, isotope 235) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.08
Range_Domain_Maximum: 82.324
Attribute_Units_of_Measure: unit-less value
Attribute:
Attribute_Label: 207Pb_235U_Unc
Attribute_Definition:
Two-sigma uncertainty for the ratio of lead (Pb, isotope 207) to uranium (U, isotope 235) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.004
Range_Domain_Maximum: 482.321
Attribute_Units_of_Measure: unit-less value
Attribute:
Attribute_Label: 206Pb_238U_Ratio
Attribute_Definition:
The ratio of lead (Pb, isotope 206) divided by uranium (U, isotope 238) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.0114
Range_Domain_Maximum: 4.5999
Attribute_Units_of_Measure: unit-less value
Attribute:
Attribute_Label: 206Pb_238U_Unc
Attribute_Definition:
Two-sigma uncertainty for the ratio of lead (Pb, isotope 206) to uranium (U, isotope 238) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.0002
Range_Domain_Maximum: 104.157
Attribute_Units_of_Measure: unit-less value
Attribute:
Attribute_Label: Error_Correlation
Attribute_Definition:
Error correlation of 2-sigma uncertainty on 207Pb/235U and 206Pb/238U ratios.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.05
Range_Domain_Maximum: 0.05
Attribute_Units_of_Measure: unit-less value
Attribute:
Attribute_Label: 207Pb_206Pb_Ratio
Attribute_Definition:
The ratio of lead (Pb, isotope 207) divided by lead (Pb, isotope 206) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 0.8256
Attribute_Units_of_Measure: unit-less value
Attribute:
Attribute_Label: 207Pb_206Pb_Unc
Attribute_Definition:
Two-sigma uncertainty for the ratio of lead (Pb, isotope 207) divided by lead (Pb, isotope 206) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 4.6034
Attribute_Units_of_Measure: unit-less value
Attribute:
Attribute_Label: 207Pb_235U_Age
Attribute_Definition:
Age in millions of years (Ma) calculated from the ratio of lead (Pb, isotope 207) to uranium (U, isotope 235) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 4490.7
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 207Pb_235U_Age_Unc_Minus
Attribute_Definition:
Two-sigma uncertainty (in millions of years, Ma) lesser than the age calculated from the ratio of lead (Pb, isotope 207) to uranium (U, isotope 235) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 6797.7
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 207Pb_235U_Age_Unc_Plus
Attribute_Definition:
Two-sigma uncertainty (in millions of years, Ma) greater than the age calculated from the ratio of lead (Pb, isotope 207) to uranium (U, isotope 235) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 4191.5
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 206Pb_238U_Age
Attribute_Definition:
Age in millions of years (Ma) calculated from the ratio of lead (Pb, isotope 206) to uranium (U, isotope 238) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 3663.5
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 206Pb_238U_Age_Unc_Minus
Attribute_Definition:
Two-sigma uncertainty (in millions of years, Ma) lesser than the age calculated from the ratio of lead (Pb, isotope 206) to uranium (U, isotope 238) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 7327.1
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 206Pb_238U_Age_Unc_Plus
Attribute_Definition:
Two-sigma uncertainty (in millions of years, Ma) greater than the age calculated from the ratio of lead (Pb, isotope 206) to uranium (U, isotope 238) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 18141.7
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 207Pb_206Pb_Age
Attribute_Definition:
Age in millions of years (Ma) calculated from the ratio of lead (Pb, isotope 207) to lead (Pb, isotope 206) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 4560
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 207Pb_206Pb_Age_Unc_Minus
Attribute_Definition:
Two-sigma uncertainty (in millions of years, Ma) lesser than the age calculated from the ratio of lead (Pb, isotope 207) to lead (Pb, isotope 206) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 8304.8
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: 207Pb_206Pb_Age_Unc_Plus
Attribute_Definition:
Two-sigma uncertainty (in millions of years, Ma) greater than the age calculated from the ratio of lead (Pb, isotope 207) to lead (Pb, isotope 206) for concordant scans.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 3725.2
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: Preferred_Age
Attribute_Definition:
Value is the preferred age (in millions of years, Ma), selected from one of the three following fields containing calculated ages for each scan: 207Pb_235U_Age, or 206Pb_238U_Age, or 207Pb_206Pb_Age.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 4560
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: Preferred_Age_Unc_Minus
Attribute_Definition:
Two-sigma uncertainty (in millions of years, Ma) lesser than the preferred age. Zero values indicate an analysis that failed to yield an age.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 8304.8
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: Preferred_Age_Unc_Plus
Attribute_Definition:
Two-sigma uncertainty (in millions of years, Ma) greater than the preferred age. Zero values indicate an analysis that failed to yield an age.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 3725.2
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: Preferred_Age_Type
Attribute_Definition:
Method used to calculate the values in the Preferred_Age field for each individual analysis that yielded a valid result. The analyses that did not yield valid ages list 'failed' in this field. Refer to the description of analytical methods, file Supplemental_Info_Analytical_Methods_A2Z.pdf, for more details.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
The following values are used: 206Pb/238U concordant scans, 207Pb/206Pb concordant scans, 207Pb/235U concordant scans, Pbc-corrected concordant scans, and Pbc-corrected isotopic sums.
Attribute:
Attribute_Label: Preferred_Age_Concordant_Scans
Attribute_Definition:
Total number of concordant scans obtained for each individual analysis.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 176
Attribute:
Attribute_Label: Preferred_Age_Total_Scans
Attribute_Definition: Total number of scans measured for each individual analysis.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 14
Range_Domain_Maximum: 179
Detailed_Description:
Entity_Type:
Entity_Type_Label: GEOCHRONOLOGY_SAMPLE_SUMMARY.csv
Entity_Type_Definition:
Table with sample information, including location, rock description, and summary of geochronology analyses.
Entity_Type_Definition_Source: Author defined
Attribute:
Attribute_Label: SAMPLE
Attribute_Definition:
Sample number assigned when sample was collected in the field. This attribute links to field Sample in tables GEOCHRONOLOGY_TITANITE_DATA and GEOCHRONOLOGY_DETRITALZIRCON_DATA.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Unique sample identifier consisting of the last two digits of the year collected, abbreviation identifying the collector, and a number and possible suffix. Collector abbreviations include: AD (J. Dumoulin), AJJ (J.V. Jones), ALR (R. Lease), AMB (Adrian Bender), KS (Karri Sicard), SB (S. Box), SK (S. Karl, and WA (Garth Graham).
Attribute:
Attribute_Label: LAB_SAMPLE_NUMBER
Attribute_Definition:
Lab sample identification. One to one correspondence to SAMPLE.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
Hyphenated numeric code assigned by A2Z laboratory for detrital zircon samples. For the titanite sample run by the Stanford-USGS SHRIMP lab, the value is identical to SAMPLE.
Attribute:
Attribute_Label: LATITUDE
Attribute_Definition: Latitude given in decimal degrees; datum NAD83.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 61.2886
Range_Domain_Maximum: 62.5722
Attribute_Units_of_Measure: decimal degrees
Attribute:
Attribute_Label: LONGITUDE
Attribute_Definition: Longitude given in decimal degrees; datum NAD83.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -154.3668
Range_Domain_Maximum: -151.4511
Attribute_Units_of_Measure: decimal degrees
Attribute:
Attribute_Label: ROCK_TYPE
Attribute_Definition: Basic rock type
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain: Values in table include diabase and sandstone.
Attribute:
Attribute_Label: ANALYSIS_TYPE
Attribute_Definition: Type of geochronologic analysis
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: U-Pb titanite
Enumerated_Domain_Value_Definition:
Sensitive high resolution ion microprobe with reverse-geometry (SHRIMP-RG) on titanite
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: U-Pb detrital zircon
Enumerated_Domain_Value_Definition:
Laser ablation-inductively coupled plasma-mass spectrometry on detrital zircons
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: ANALYSIS_LOCATION
Attribute_Definition: Laboratory or contractor where sample was analyzed.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Stanford USGS SHRIMP LAB
Enumerated_Domain_Value_Definition:
Stanford-U.S. Geological Survey (USGS) sensitive high resolution ion microprobe with reverse-geometry (SHRIMP-RG) at Stanford University, California
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Apatite to Zircon
Enumerated_Domain_Value_Definition: Apatite to Zircon, Inc. GeoSep Services, Moscow, Idaho
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: ANALYSIS_METHOD
Attribute_Definition: Laboratory equipment and methodology used to collect data
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: ShrimpRG
Enumerated_Domain_Value_Definition: Sensitive high resolution ion microprobe with reverse-geometry
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: LAICPMS
Enumerated_Domain_Value_Definition: laser ablation inductively coupled plasma mass spectrometry
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: ROCK_CLASS
Attribute_Definition: Basic rock classification
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain: Values include igneous and sedimentary
Attribute:
Attribute_Label: INTERPRETED_AGE_MA
Attribute_Definition: Interpreted age for sample, in millions of years (Ma)
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 97
Range_Domain_Maximum: 97
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: INTERPRETED_AGE_UNC_MA
Attribute_Definition:
Two-sigma uncertainty of interpreted age calculated for the sample, in millions of years (Ma)
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 2.2
Range_Domain_Maximum: 2.2
Attribute_Units_of_Measure: millions of years (Ma)
Attribute:
Attribute_Label: INTERPRETED_AGE_METHOD
Attribute_Definition: Method used to calculate the value in field INTERPRETED_AGE_MA
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: concordia age
Enumerated_Domain_Value_Definition: age interpreted from 206Pb/238U vs 207Pb/235U concordia diagram
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute:
Attribute_Label: INTERPRETED_AGE_NUMBER_ANALYSES
Attribute_Definition:
Number of analyses used to calculate the value in field INTERPRETED_AGE_MA.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 11
Range_Domain_Maximum: 11
Attribute:
Attribute_Label: INTERPRETED_AGE_MSWD
Attribute_Definition:
Mean square of weighted deviates for calculated value in field INTERPRETED_AGE_MA
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1.9
Range_Domain_Maximum: 1.9
Attribute:
Attribute_Label: INTERPRETED_AGE_TYPE
Attribute_Definition: Geological significance of interpreted age
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: metamorphism
Enumerated_Domain_Value_Definition: Alteration of rock by heat or pressure
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: detrital
Enumerated_Domain_Value_Definition:
A detrital age from a sedimentary rock can set a maximum depositional age, determine the provenance age, and aid in reconstructing the tectonic setting.
Enumerated_Domain_Value_Definition_Source: Author defined
Detailed_Description:
Entity_Type:
Entity_Type_Label: GEOCHRONOLOGY_DATA_DOCUMENTATION.csv
Entity_Type_Definition:
Table listing the name of all fields in each table, including a brief description of the field and the units of the data if applicable.
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:
Unrepresentable_Domain:
The data tables in this data set include GEOCHRONOLOGY_TITANITE_DATA, GEOCHRONOLOGY_DETRITALZIRCON_DATA, and GEOCHRONOLOGY_SAMPLE_SUMMARY.
Attribute:
Attribute_Label: Field
Attribute_Definition: Field name found in data table listed in field Table
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain:
The field names are single words or concatenated abbreviations that describe the contents of the field.
Attribute:
Attribute_Label: Description
Attribute_Definition: Brief description of the contents of the field
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:
Unrepresentable_Domain: Brief description of the contents of the field
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: %
Enumerated_Domain_Value_Definition: percent
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: degrees
Enumerated_Domain_Value_Definition: degrees Celsius
Enumerated_Domain_Value_Definition_Source: Author defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Ma
Enumerated_Domain_Value_Definition: mega-annum or one million years
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: n/a
Enumerated_Domain_Value_Definition: not applicable
Enumerated_Domain_Value_Definition_Source: Author defined
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: 99508-4626
Country: U.S.A.
Contact_Voice_Telephone: 907-786-7000
Contact_Electronic_Mail_Address: ascweb@usgs.gov
Resource_Description: Authoritative source the for the 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 (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: CSV
Format_Information_Content:
Zip file contains the data in CSV format, FGDC metadata in XML and HTML formats, and supplementary information about laboratory methods.
File_Decompression_Technique:
Compression applied by the 7-Zip utility using default compression (5). The file can be decompressed and unpacked by open source or commercially available unzip tools.
Transfer_Size: 0.65
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: https://doi.org/10.5066/P9JV5LM9
Fees: None
Metadata_Reference_Information:
Metadata_Date: 20201125
Metadata_Review_Date: 20200204
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey, Alaska Science Center
Contact_Address:
Address_Type: mailing and physical address
Address: 4210 University Drive
City: Anchorage
State_or_Province: Alaska
Postal_Code: 99508-4626
Country: U.S.A.
Contact_Voice_Telephone: 907-786-7000
Contact_Electronic_Mail_Address: ascweb@usgs.gov
Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Generated by mp version 2.9.50 on Thu Jun 11 14:09:04 2020