Low-Temperature Thermochronometric Data from the Revelation Mountains, Western Alaska Range, 2013-2018

Identification_Information:

Citation:

Citation_Information:

Originator: Richard O. Lease (ORCID: 0000-0003-2582-8966)
Publication_Date: 20180913
Title:

Geospatial_Data_Presentation_Form: tabular digital data
Publication_Information:

Publication_Place: Anchorage, AK
Publisher: U.S. Geological Survey, Alaska Science Center

Other_Citation_Details:

Suggested citation: Lease, R.O., 2018, Low-Temperature Thermochronometric Data from the Revelation Mountains, Western Alaska Range, 2013-2018: U.S. Geological Survey data release, https://doi.org/10.5066/P9ZNIHT7

Online_Linkage: https://doi.org/10.5066/P9ZNIHT7
Larger_Work_Citation:

Citation_Information:

Originator: Richard O. Lease (ORCID: 0000-0003-2582-8966)
Publication_Date: 2018
Title:

Pliocene Erosional Pulse and Glacier-Landscape Feedbacks in the Western Alaska Range

Geospatial_Data_Presentation_Form: journal article
Series_Information:

Series_Name: Earth and Planetary Science Letters
Issue_Identification: v. 497, p. 62-68

Other_Citation_Details:

Suggested citation: Lease, R.O., 2018, Pliocene Erosional Pulse and Glacier-Landscape Feedbacks in the Western Alaska Range: Earth and Planetary Science Letters, v. 497, p. 62-68, https://doi.org/10.1016/j.epsl.2018.06.009

Online_Linkage: https://doi.org/10.1016/j.epsl.2018.06.009

Description:

Abstract:

This data set provides low-temperature thermochronometric data from 16 rock samples collected from the Revelation Mountains area in western Alaska Range. These data are from three different analyses used to estimate cooling ages: 1) apatite (U-Th)/He, 2) zircon (U-Th)/He, and 3) apatite fission-track.

Purpose:

This dataset was collected to ascertain the exhumation history of the western Alaska Range study area over the past 20 million years. A particular focus was placed on quantifying how erosion rates evolved during Pliocene-Pleistocene glaciation.

Supplemental_Information:

Lease, R.O., 2018, Pliocene Erosional Pulse and Glacier-Landscape Feedbacks in the Western Alaska Range: Earth and Planetary Science Letters, v. 497, p. 62-68, https://doi.org/10.1016/j.epsl.2018.06.009

Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2018

Currentness_Reference: publication date

Status:

Progress: Complete
Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -154.202
East_Bounding_Coordinate: -153.884
North_Bounding_Coordinate: 61.822
South_Bounding_Coordinate: 61.394

Keywords:

Theme:

Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:ASC192

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: geoscientificInformation

Theme:

Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: geochronology
Theme_Keyword: radiometric dating
Theme_Keyword: fission-track dating
Theme_Keyword: tectonic processes

Theme:

Theme_Keyword_Thesaurus: NASA GCMD Earth Science Keywords Thesaurus
Theme_Keyword: earth science
Theme_Keyword: land surface
Theme_Keyword: erosion/sedimentation
Theme_Keyword: geomorphic landforms/processes
Theme_Keyword: tectonic uplift
Theme_Keyword: mountains
Theme_Keyword: glaciation

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword: low-temperature thermochronology
Theme_Keyword: geochronology
Theme_Keyword: apatite
Theme_Keyword: zircon
Theme_Keyword: (U-Th)/He
Theme_Keyword: fission track

Place:

Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
Place_Keyword: State of Alaska
Place_Keyword: Alaska Range
Place_Keyword: Revelation Mountains
Place_Keyword: Mount Hesperus

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_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

Data_Set_Credit:

This data set includes 16 different samples collected in the western Alaska Range. (U-Th)/He thermochronology was performed on 15 apatite samples and 9 zircon samples at University of Colorado TRaIL by James R. Metcalf. One sample was analyzed by (U-Th)/He at the University of Texas in Austin, Texas. Apatite fission-track analysis was performed on 9 samples at GeoSep Services by Paul B. O'Sullivan.

Cross_Reference:

Citation_Information:

Originator: Jones, James V. (ORCID: 0000-0002-6602-5935)
Originator: Todd, Erin (ORCID: 0000-0002-4871-9730)
Publication_Date: 2014
Title:

Metallogeny and Tectonics of the Neacola Mountains and Lake Clark region, south-central Alaska

Publication_Information:

Publication_Place: Anchorage, Alaska
Publisher: U.S. Geological Survey, Alaska Science Center

Online_Linkage: https://alaska.usgs.gov/portal/project.php?project_id=388

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

All analyses included standards run throughout the process to monitor procedures and maintain consistency. Specific average estimated accuracy of the standards used for analyses are available for analyses conducted at the University of Colorado. Shards of Durango Fluoroapatite Standard run in conjunction with AHe analyses at the University of Colorado yielded weighted mean dates of 31.8 +/- 0.6 Ma (n=7, 201412 (calendar date)), 31.8 +/- 1.3 Ma (n=13; 201502), 31.9 +/- 1.7 Ma (n=11, 201504), and 31.5 +/- 2.6 Ma (n=10; 201509). Fish Canyon Tuff zircon standards run in conjunction with ZHe analyses at the University of Colorado yielded weighted mean dates of 28.5 =/- 0.8 Ma (n=6, 201503), 28.1 +/- 0.6 Ma (n=4; 201504), and 29.2 +/- 1.3 Ma (n=6; 201510).

Logical_Consistency_Report:

Blank cells in the data set represent either a sample not analyzed or an age not reported. Further explanation available in Attribute_Definition.

Completeness_Report:

This data set is complete. Not every sample was analyzed by all three dating methods due to availability of material suitable for dating and funding constraints.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

A handheld GPS was used to locate samples #3, 4, 9, 15, and 16 in the field, and have a horizontal accuracy of less than 5 meters. The locations of the other samples were digitized from the original NAD27 topographic sheets used during geologic field mapping, then converted to WGS84. These samples have an estimated horizontal accuracy of less than 100 meters. All samples analyzed were collected from features of topographic prominence and are easy to locate.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

Elevations were determined from a DEM with 10-meter horizontal resolution. Elevation errors are <30 meters, except for samples #10 and 11, which are located near cliffs, have errors +/- 75 meters. DEM data from U.S. Geological Survey, The National Map 2017, 3DEP products and services: The National Map, 3D Elevation Program Web page.

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: Donelick, R.A.
Originator: O'Sullivan, P.B.
Originator: Ketcham, R.A.
Publication_Date: 2005
Title: Apatite fission-track analysis
Geospatial_Data_Presentation_Form: journal article
Series_Information:

Series_Name: Reviews in Mineralogy and Geochemistry
Issue_Identification: volume 58, p. 49-94

Publication_Information:

Publication_Place: Chantilly, VA
Publisher: Mineralogical Society of America

Online_Linkage: https://doi.org/10.2138/rmg.2005.58.3

Type_of_Source_Media: online
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2005

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: Donelick and others, 2005
Source_Contribution:

Full description of analytical procedures of apatite fission-track analyses.

Source_Information:

Source_Citation:

Citation_Information:

Originator: Reiners, P.W.
Publication_Date: 2005
Title: Zircon (U-Th)/He thermochronometry
Geospatial_Data_Presentation_Form: journal article
Series_Information:

Series_Name: Reviews in Mineralogy and Geochemistry
Issue_Identification: volume 58, p 151-179

Publication_Information:

Publication_Place: Chantilly, VA
Publisher: Mineralogical Society of America

Online_Linkage: https://doi.org/10.2138/rmg.2005.58.6

Type_of_Source_Media: online
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2005

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: Reiners, 2005
Source_Contribution:

Full description of analytical procedures of zircon (U-Th)/He thermochronometry.

Source_Information:

Source_Citation:

Citation_Information:

Originator: Farley, K.A.
Originator: Stockli, D.F.
Publication_Date: 2002
Title: (U-Th)/He dating of phosphates: apatite, monazite, and xenotime
Geospatial_Data_Presentation_Form: journal article
Series_Information:

Series_Name: Reviews in Mineralogy and Geochemistry
Issue_Identification: volume 48, p. 559-577

Publication_Information:

Publication_Place: Chantilly, VA
Publisher: Mineralogical Society of America

Online_Linkage: https://doi.org/10.2138/rmg.2002.48.15

Type_of_Source_Media: online
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2002

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: Farley and Stockli, 2002
Source_Contribution:

Full description of analytical procedures of apatite (U-Th)/He dating.

Source_Information:

Source_Citation:

Citation_Information:

Originator: Lease, Richard O.
Publication_Date: 2018
Title:

Pliocene erosional pulse and glacier-landscape feedbacks in the western Alaska Range: Appendix A. Supplementary Material, Laboratory and Modeling Methods

Geospatial_Data_Presentation_Form: journal article
Series_Information:

Series_Name: Earth and Planetary Science Letters
Issue_Identification: v. 497, p. 62-68

Publication_Information:

Publication_Place: Amsterdam, Netherlands
Publisher: Elsevier

Online_Linkage: https://doi.org/10.1016/j.epsl.2018.06.009

Type_of_Source_Media: online
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2018

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: Lease, 2018
Source_Contribution:

The larger work citation which interprets this data. Also includes supplementary material with full description of laboratory procedures and modeling methods of apatite fission track, and apatite and zircon (U-Th)/He analyses of this study.

Process_Step:

Process_Description:

Apatite fission-track, AFT. Apatite grain mounts were polished to expose internal grain surfaces and etched in 5.5N HNO3. Spontaneous fission tracks were counted in unpolarized light at 2000x magnification. The 238U concentrations from grain surfaces were measured on a Thermo Element 2 high resolution single-collector ICPMS equipped with a New Wave ND-YAG 213nm laser ablation system. The fission track ages were calculated using: (a) the ratio of the density of natural fission tracks present in the grain to the amount of 238U present, and (b) a modified version of the radioactive decay equation that includes a LA-ICPMS zeta calibration factor (Donelick and others, 2005).

Process_Date: 2015

Process_Step:

Process_Description:

Apatite and zircon (U-Th)/He, AHe and ZHe. Individual mineral grains were screened for quality, size, shape, and inclusions using a Leica M165 binocular microscope. Handpicked grains were measured for alpha-ejection correction, then placed in Nb packets and loaded into an ASI Alphachron He extraction and measurement line. Packets were heated to 800-1000°C for 5 minutes (apatite) or 10 minutes (zircon) to extract radiogenic 4He, which was analyzed on a Balzers PrismaPlus QME220 quadrupole mass spectrometer. Degassed grains were then taken to a clean lab for dissolution using standard procedures. Sample solutions were analyzed for U, Th, and Sm content using a Thermo Element 2 magnetic sector mass spectrometer. (U-Th)/He dates and all associated data were calculated on a custom spreadsheet (Farley and Stockli, 2002).

Process_Date: 2015

Spatial_Data_Organization_Information:

Indirect_Spatial_Reference:

The Revelation Mountains region describes a general area named on USGS topographic maps near latitude 61.5N and longitude 154.1W.

Direct_Spatial_Reference_Method: point

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.001
Longitude_Resolution: 0.001
Geographic_Coordinate_Units: Decimal degrees

Geodetic_Model:

Horizontal_Datum_Name: WGS84
Ellipsoid_Name: WGS84
Semi-major_Axis: 6378137.0
Denominator_of_Flattening_Ratio: 298.257223563

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Datum_Name: North American Vertical Datum of 1988 (NAVD 88)
Altitude_Resolution: 1.000000
Altitude_Distance_Units: meters
Altitude_Encoding_Method: Implicit coordinate

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: thermochronology_sampleAttributes_RevelationMtns_lease_2018.csv
Entity_Type_Definition:

Table with sample descriptions. Includes sample location and elevation, and brief rock description

Entity_Type_Definition_Source: author defined

Attribute:

Attribute_Label: map_no
Attribute_Definition:

Sample identifier used on maps, diagrams, and tables in publication Lease (2018).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 1
Range_Domain_Maximum: 16

Attribute:

Attribute_Label: field_id
Attribute_Definition:

Sample identifier assigned when the sample was collected in the field. It is a concatenation of year collected, an abbreviation identifying the collector, and a number.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Unique identifier for a sample

Attribute:

Attribute_Label: latitude
Attribute_Definition: Latitude given in decimal degrees; datum WGS84
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 61.394
Range_Domain_Maximum: 61.822
Attribute_Units_of_Measure: decimal degrees

Attribute:

Attribute_Label: longitude
Attribute_Definition: Longitude given in decimal degrees; datum WGS84
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: -154.202
Range_Domain_Maximum: -153.884
Attribute_Units_of_Measure: decimal degrees

Attribute:

Attribute_Label: elevation_m
Attribute_Definition:

Elevation of collected samples based on DEM with 10-meter horizontal resolution. Elevation errors are <30 meters, except for samples #10 and 11, which are located near cliffs, have error +/- 75 meters. DEM data from U.S. Geological Survey, The National Map 2017, 3DEP products and services: The National Map, 3D Elevation Program Web page.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 518
Range_Domain_Maximum: 2057
Attribute_Units_of_Measure: meters

Attribute:

Attribute_Label: description
Attribute_Definition: Rock type determined in the field using visual observations.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Unrepresentable_Domain: rock type determined visual observation

Detailed_Description:

Entity_Type:

Entity_Type_Label: thermochronology_apatiteUThHe_RevelationMtns_lease_2018
Entity_Type_Definition:

Analytical data and uncertainties for apatite (U-Th)/He analyses. Each sample is represented by several single-grain splits. Data are grain dimensions, and U, Th, Sm, and He measurements. Geologic age and other values determined according to Farley and Stockli (2002) and presented in millions of years.

Entity_Type_Definition_Source: author defined

Attribute:

Attribute_Label: map_no
Attribute_Definition:

Sample identifier used on maps, diagrams, and tables in publication Lease (2018).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 1
Range_Domain_Maximum: 16

Attribute:

Attribute_Label: lab
Attribute_Definition: Identifies the laboratory where analysis was performed.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: University of Colorado
Enumerated_Domain_Value_Definition:

University of Colorado Thermochronology Research and Instrumentation Laboratory (TRaIL). Analyses performed by James R. Metcalf.

Enumerated_Domain_Value_Definition_Source: author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: University of Texas
Enumerated_Domain_Value_Definition: University of Texas (U-Th)/He Laboratory in Austin, Texas
Enumerated_Domain_Value_Definition_Source: author defined

Attribute:

Attribute_Label: field_id
Attribute_Definition:

Sample identifier assigned when the sample was collected in the field. It is a concatenation of the year collected, an abbreviation identifying the collector, and a number. Each field_id is presented multiple times as this table contains analyses of different single-grain splits for each sample.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Unique identifier for a sample

Attribute:

Attribute_Label: sample_id
Attribute_Definition: Concatenation of field_id and a laboratory split identifier.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Unique identifier for a laboratory sample

Attribute:

Attribute_Label: mean_length
Attribute_Definition:

Mean length of two measurements of an apatite grain measured in micrometers (microns). Grains were measured using a Leica M165 binocular microscope. Measurements not available for samples analyzed at the University of Texas.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 90
Range_Domain_Maximum: 296
Attribute_Units_of_Measure: micrometer (micron)

Attribute:

Attribute_Label: mean_width
Attribute_Definition:

Mean width of two measurement of an apatite grain measured in micrometers (microns). Grains were measured using a Leica M165 binocular microscope. Measurements not available for samples analyzed at the University of Texas.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 56
Range_Domain_Maximum: 143
Attribute_Units_of_Measure: micrometer (micron)

Attribute:

Attribute_Label: rs
Attribute_Definition:

Spherical radius of apatite grains calculated based on mean width and mean length and measured in micrometers (microns).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 33
Range_Domain_Maximum: 80
Attribute_Units_of_Measure: micrometer (micron)

Attribute:

Attribute_Label: 4He_nmol_g
Attribute_Definition: Measure of radiogenic 4He (helium) in nanomole/gram.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.049
Range_Domain_Maximum: 101.738
Attribute_Units_of_Measure: nanomole per gram (nmol/g)

Attribute:

Attribute_Label: 4He_1sigma
Attribute_Definition:

One sigma analytical error of the radiogenic 4He (helium) measurement, given in nanomole/gram.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.001
Range_Domain_Maximum: 0.128
Attribute_Units_of_Measure: nanomole per gram (nmol/g)

Attribute:

Attribute_Label: U_ppm
Attribute_Definition: Measure of U (uranium) in parts per million.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 1.3
Range_Domain_Maximum: 310.5
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: U_1sigma
Attribute_Definition:

One sigma analytical error of the U (uranium) measurement, given in parts per million.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.1
Range_Domain_Maximum: 3.9
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: Th_ppm
Attribute_Definition: Measure of Th (thorium) in parts per million.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 3.0
Range_Domain_Maximum: 213.5
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: Th_1sigma
Attribute_Definition:

One sigma analytical error of the Th (thorium) measurement, given in parts per million.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.1
Range_Domain_Maximum: 3.0
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: Sm_ppm
Attribute_Definition: Measure of Sm (samarium) in parts per million.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 2.9
Range_Domain_Maximum: 143.1
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: Sm_1sigma
Attribute_Definition:

One sigma analytical error of the Sm (samarium) measurement, given in parts per million.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.3
Range_Domain_Maximum: 6.6
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: eU
Attribute_Definition:

Effective uranium concentration, a parameter that weights the decay of the two parents for their alpha productivity, computed as U + 0.235xTh.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 3.4
Range_Domain_Maximum: 311.9

Attribute:

Attribute_Label: raw_date_ma
Attribute_Definition:

Raw date in millions of years (Farley and Stockli, 2002). Date has not been corrected for alpha ejection.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.8
Range_Domain_Maximum: 380.6
Attribute_Units_of_Measure: millions of years (Ma)

Attribute:

Attribute_Label: Ft_corr
Attribute_Definition:

Alpha ejection correction, which is the fraction of 4He alpha particles retained, and is calculated from grain dimensions and chemistry (Farley and Stockli, 2002).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.56
Range_Domain_Maximum: 0.80

Attribute:

Attribute_Label: Ft_corr_1sigma_pct
Attribute_Definition:

One sigma error on the alpha ejection parameter, expressed in percentage.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 7
Range_Domain_Maximum: 23
Attribute_Units_of_Measure: percent

Attribute:

Attribute_Label: corr_date_ma
Attribute_Definition:

Corrected date in millions of years. Date has been corrected for alpha ejection and is calculated as raw_date divided by Ft_corr (Farley and Stockli, 2002).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 1.3
Range_Domain_Maximum: 661.3
Attribute_Units_of_Measure: millions of years (Ma)

Attribute:

Attribute_Label: corr_date_1sigma
Attribute_Definition:

One sigma analytical uncertainty on date based on error propagation from measured quantities.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.02
Range_Domain_Maximum: 6.43
Attribute_Units_of_Measure: millions of years (Ma)

Attribute:

Attribute_Label: analy_date
Attribute_Definition: Date of analysis given in month and year, YYYYMM
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 201412
Range_Domain_Maximum: 201509
Attribute_Units_of_Measure: YYYYMM

Attribute:

Attribute_Label: comments
Attribute_Definition:

Comments about anomalous records which were excluded from age calculations in Lease, 2018

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Unrepresentable_Domain: free text

Detailed_Description:

Entity_Type:

Entity_Type_Label: thermochronology_zirconUThHe_RevelationMtns_lease_2018.csv
Entity_Type_Definition:

Analytical data and uncertainties of zircon (U-Th)/He analyses. Each sample is represented by several single-grain sample splits. Data are grain dimensions, U, Th, Sm, and He measurements. Geologic age and other values determined according to Reiners (2005) and presented in millions of years.

Entity_Type_Definition_Source: author defined

Attribute:

Attribute_Label: map_no
Attribute_Definition:

Sample identifier used on maps, diagrams, and tables in publication Lease (2018).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 1
Range_Domain_Maximum: 16

Attribute:

Attribute_Label: lab
Attribute_Definition: Identifies the laboratory where analysis was performed.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: University of Colorado
Enumerated_Domain_Value_Definition:

University of Colorado Thermochronology Research and Instrumentation Laboratory (TRaIL). Analyses performed by James R. Metcalf.

Enumerated_Domain_Value_Definition_Source: author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: University of Texas
Enumerated_Domain_Value_Definition: University of Texas (U-Th)/He Laboratory in Austin, Texas
Enumerated_Domain_Value_Definition_Source: author defined

Attribute:

Attribute_Label: field_id
Attribute_Definition:

Sample identifier assigned when the sample was collected in the field. It is a concatenation of the year collected, an abbreviation identifying the collector, and a number. Each field_id is presented multiple time as this table contains the analyses of different single-grain splits for each sample.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Unique identifier for a sample

Attribute:

Attribute_Label: sample_id
Attribute_Definition: Concatenation of field_id and laboratory split identifier.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Unique identifier for a laboratory sample

Attribute:

Attribute_Label: mean_length
Attribute_Definition:

Mean length of two measurements of a zircon grain measured in micrometers (microns). Grains were measured using a Leica M165 binocular microscope. Measurements are available for samples analyzed at the University of Texas.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 146
Range_Domain_Maximum: 528
Attribute_Units_of_Measure: micrometer (micron)

Attribute:

Attribute_Label: mean_width
Attribute_Definition:

Mean width of two measurements on a zircon grain measured in micrometers (microns). Grains were measured using a Leica M165 binocular microscope. Measurements not available for samples analyzed at the University of Texas.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 60
Range_Domain_Maximum: 153
Attribute_Units_of_Measure: micrometer (micron)

Attribute:

Attribute_Label: rs
Attribute_Definition:

Spherical radius of zircon grains measured in micrometers (microns).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 39
Range_Domain_Maximum: 88
Attribute_Units_of_Measure: micrometer (micron)

Attribute:

Attribute_Label: 4He_nmol_g
Attribute_Definition: Measure of radiogenic 4He (helium) in nanomole/gram.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 24.012
Range_Domain_Maximum: 640.742
Attribute_Units_of_Measure: nanomole per gram (nmol/g)

Attribute:

Attribute_Label: 4He_1sigma
Attribute_Definition:

One sigma analytical error of the radiogenic 4He (helium) measurement, given in nanomole/gram.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.022
Range_Domain_Maximum: 1.221
Attribute_Units_of_Measure: nanomole per gram (nmol/g)

Attribute:

Attribute_Label: U_ppm
Attribute_Definition: Measure of U (uranium) in parts per million.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 316.8
Range_Domain_Maximum: 7241.6
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: U_1sigma
Attribute_Definition:

One sigma analytical error of the U (uranium) measurement, given in parts per million.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 5.3
Range_Domain_Maximum: 235.0
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: Th_ppm
Attribute_Definition: Measure of Th (thorium) in parts per million.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 36.2
Range_Domain_Maximum: 2745.5
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: Th_1sigma
Attribute_Definition:

One sigma analytical error of the Th (thorium) measurement, given in parts per million.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.7
Range_Domain_Maximum: 86.3
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: Sm_ppm
Attribute_Definition: Measure of Sm (samarium) in parts per million.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.4
Range_Domain_Maximum: 197.1
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: Sm_1sigma
Attribute_Definition:

One sigma analytical error of the Sm (samarium) measurement, given in parts per million.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.01
Range_Domain_Maximum: 8.82
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: eU
Attribute_Definition:

Effective uranium concentration, a parameter that weights the decay of the two parents for their alpha productivity, computed as U + 0.235 x Th.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 326.6
Range_Domain_Maximum: 7886.8

Attribute:

Attribute_Label: raw_date_ma
Attribute_Definition:

Raw date in millions of years (Reiners, 2005). Date has not been corrected for alpha ejection.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 9.7
Range_Domain_Maximum: 23.6
Attribute_Units_of_Measure: millions of years (Ma)

Attribute:

Attribute_Label: Ft_corr
Attribute_Definition:

Alpha ejection correction, which is the fraction of 4He alpha particles retained, and is calculated from grain dimensions and chemistry (Reiners, 2005).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.71
Range_Domain_Maximum: 0.87

Attribute:

Attribute_Label: Ft_corr_1sigma_pct
Attribute_Definition:

One sigma error on the alpha ejection parameter, expressed in percentage.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 7
Range_Domain_Maximum: 12
Attribute_Units_of_Measure: percent

Attribute:

Attribute_Label: corr_date_ma
Attribute_Definition:

Corrected date in millions of years. Date has been corrected for alpha ejection and is calculated as raw_date divided by Ft_corr (Reiners, 2005).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 13.20
Range_Domain_Maximum: 29.8
Attribute_Units_of_Measure: millions of years (Ma)

Attribute:

Attribute_Label: corr_data_1sigma
Attribute_Definition:

One sigma analytical uncertainty on date based on error propagation from measured quantities.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.1
Range_Domain_Maximum: 1.5
Attribute_Units_of_Measure: millions of years (Ma)

Attribute:

Attribute_Label: analy_date
Attribute_Definition: Date of analysis given in month and year, YYYYMM.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 201503
Range_Domain_Maximum: 201510
Attribute_Units_of_Measure: YYYYMM

Detailed_Description:

Entity_Type:

Entity_Type_Label:

thermochronology_apatiteFissionTracks_RevelationMtns_lease_2018.csv

Entity_Type_Definition:

Data for apatite fission-track single-grain analyses. All analyses performed by Paul B. O'Sullivan, GeoSep Services, Moscow, Idaho. Primary Zeta = 12.357 +/- 0.2251 (1 sigma) Geologic age determined by apatite fission-track (AFT) dating, which has an effective closure temperature of about 110 degrees Celsius. Age is presented in millions of years. Blank cell represents that the sample was not analyzed.

Entity_Type_Definition_Source: author defined

Attribute:

Attribute_Label: map_no
Attribute_Definition:

Sample identifier used on maps, diagrams, and tables in publication Lease (2018).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 2
Range_Domain_Maximum: 16

Attribute:

Attribute_Label: field_id
Attribute_Definition:

Sample identifier assigned when the sample was collected in the field. It is a concatenation of the year collected, and abbreviation identifying the collector, and a number. Each field_id is presented multiple times as this table contains analyses of different single grain splits for each sample.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Unrepresentable_Domain: free text

Attribute:

Attribute_Label: grain
Attribute_Definition:

Numeric code assigned to a single apatite grain. The numeric code is unique for each sample (field_id).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential numeric value for each sample (field_id), ranging from 1 to 40.

Attribute:

Attribute_Label: Ns
Attribute_Definition: Number of spontaneous tracks counted.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0
Range_Domain_Maximum: 57

Attribute:

Attribute_Label: area
Attribute_Definition: Surface area of apatite grain in which tracks were counted.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.00000874
Range_Domain_Maximum: 0.0000485
Attribute_Units_of_Measure: cm^2, or centimeter squared

Attribute:

Attribute_Label: U_Ca
Attribute_Definition: Ratio of 238Uranium / 43Calcium
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.0012614
Range_Domain_Maximum: 1.4506

Attribute:

Attribute_Label: U_Ca_1sigma
Attribute_Definition: One sigma analytical error of 238Uranium/43Calcium ratio.
Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.00009
Range_Domain_Maximum: 0.24038

Attribute:

Attribute_Label: Dpar_um
Attribute_Definition:

Dpar represents the diameter of fission-track etch pits parallel to the crystallographic c-axis. For each apatite grain measured, between one and four etch pit diameters were measured and an arithmetic mean Dpar value calculated.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 1.34
Range_Domain_Maximum: 2.35
Attribute_Units_of_Measure: micrometer or micron

Attribute:

Attribute_Label: Dper_um
Attribute_Definition:

Dper represents the diameter of fission-track etch pits perpendicular to the crystallographic c-axis. For each apatite grain measured, between one and four etch pit diameters were measured and an arithmetic mean Dper value calculated.

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.19
Range_Domain_Maximum: 0.60
Attribute_Units_of_Measure: micrometer or micron

Attribute:

Attribute_Label: U_ppm
Attribute_Definition:

Uranium, in parts per million, measured using the laser ablation inductively couple plasma-mass spectrometry (LA-ICPMS) method (Donelick and others, 2005).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 1
Range_Domain_Maximum: 292
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: Th_ppm
Attribute_Definition:

Thorium, in parts per million, measured using the laser ablation inductively couple plasma-mass spectrometry (LA-ICPMS) method (Donelick and others, 2005)

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 2
Range_Domain_Maximum: 1238
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: Sm_ppm
Attribute_Definition:

Samarium, in parts per million, measured using the laser ablation inductively couple plasma-mass spectrometry (LA-ICPMS) method (Donelick and others, 2005).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 23
Range_Domain_Maximum: 2264
Attribute_Units_of_Measure: parts per million (ppm)

Attribute:

Attribute_Label: FT_age_ma
Attribute_Definition:

Fission-track age calculated for the single apatite grain (Donelick and others, 2005).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.0
Range_Domain_Maximum: 129.9
Attribute_Units_of_Measure: millions of years (Ma)

Attribute:

Attribute_Label: lower95CI_ma
Attribute_Definition:

Lower 95th confidence interval fission-track age in millions of years (Donelick and others, 2005).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.0
Range_Domain_Maximum: 88.8
Attribute_Units_of_Measure: millions of years (Ma)

Attribute:

Attribute_Label: upper95CI_ma
Attribute_Definition:

Upper 95th confidence interval fission-track age in millions of years (Donelick and others, 2005).

Attribute_Definition_Source: author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 2.8
Range_Domain_Maximum: 937.6
Attribute_Units_of_Measure: millions of years (Ma)

Low-Temperature Thermochronometric Data from the Revelation Mountains, Western Alaska Range, 2013-2018

Metadata: