Lease, Richard O. (ORCID: 0000-0003-2582-8966) 20180913 tabular digital data Anchorage, Alaska U.S. Geological Survey, Alaska Science Center 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 https://doi.org/10.5066/P9ZNIHT7 This dataset 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. 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. 2018 publication date Complete None planned -154.202 -153.884 61.822 61.394 USGS Metadata Identifier USGS:ASC192 ISO 19115 Topic Category GeoScientificInformation NASA GCMD Earth Science Keyword Thesaurus Earth science USGS Thesaurus Geology Geochronology Radiometric dating Fission-track dating None Low-temperature thermochronology Apatite Zircon (U-Th)/He geochronology Geographic Names Information System (GNIS) Alaska Alaska Range Revelation Mountains Mount Hesperus No access constraints. No use constraints. These data are marked with a Creative Common CC0 1.0 Universal License and are in the public domain. It is requested that this USGS data release be cited for any subsequent publications that reference or utilize these data. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. U.S. Geological Survey, Alaska Science Center Mailing and Physical

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Anchorage Alaska 99508 USA 907-786-7000 gs-ak_asc_datamanagers@usgs.gov 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. Lease, R.O. 2018 journal article Earth and Planetary Science Letters 497:62-68 online Elsevier Lease, R.O., 2018, Pliocene erosional pulse and glacier-landscape feedbacks in the western Alaska Range. Earth and Planetary Science Letters 497:62-68. https://doi.org/10.1016/j.epsl.2018.06.009 https://doi.org/10.1016/j.epsl.2018.06.009 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). Blank cells in the data set represent either a sample not analyzed or an age not reported. This dataset is complete. Not every sample was analyzed by all three dating methods due to availability of material suitable for dating and funding constraints. 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. 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). Unknown 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). Unknown LITERATURE CITED: Donelick, R.A., O'Sullivan, P.B., Ketcham, R.A., 2005. Apatite fission-track analysis. Reviews in Mineralogy and Geochemistry 58(1):49-94. https://doi.org/10.2138/rmg.2005.58.3 Farley, K.A., Stockli, D.F., 2002. (U-Th)/He dating of phosphates: apatite, monazite, and xenotime. Reviews in Mineralogy and Geochemistry 48(1):559-577. https://doi.org/10.2138/rmg.2002.48.15 Lease, R.O., 2018, Pliocene erosional pulse and glacier-landscape feedbacks in the western Alaska Range. Earth and Planetary Science Letters 497:62-68. https://doi.org/10.1016/j.epsl.2018.06.009 Reiners, P.W., 2005. Zircon (U-Th)/He thermochronometry. Reviews in Mineralogy and Geochemistry 58(1):151-179. https://doi.org/10.2138/rmg.2005.58.6 Unknown Point 0.001 0.001 Decimal degrees World Geodetic System of 1984 (WGS84) World Geodetic System of 1984 (WGS84) 6378137 298.257223563 North American Vertical Datum of 1988 (NAVD88) 1.000000 meters Implicit coordinate thermochronology_sampleAttributes_revelationMtns_lease.csv Table with sample descriptions. Includes sample location and elevation, and brief rock description. Presented in a Comma Separated Value (CSV) formatted table. Author defined map_no Sample identifier used on maps, diagrams, and tables in publication Lease (2018). Author defined 1 16 field_id 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. Author defined Unique identifier for a sample latitude Latitude given in decimal degrees; datum WGS84 Author defined 61.394 61.822 Decimal degrees (WGS84) longitude Longitude given in decimal degrees; datum WGS84 Author defined -154.202 -153.884 Decimal degrees (WGS84) elevation_m 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. Author defined 518 2057 meters description Rock type determined in the field using visual observations. Author defined rock type determined visual observation thermochronology_UThHe_apatite_revelationMtns_lease.csv Table with 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. Presented in a Comma Separated Value (CSV) formatted table. Author defined map_no Sample identifier used on maps, diagrams, and tables in publication Lease (2018). Author defined 1 16 lab Identifies the laboratory where analysis was performed. Author defined University of Colorado University of Colorado Thermochronology Research and Instrumentation Laboratory (TRaIL). Analyses performed by James R. Metcalf. Author defined University of Texas University of Texas (U-Th)/He Laboratory in Austin, Texas Author defined field_id 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. Author defined Unique identifier for a sample sample_id Concatenation of field_id and a laboratory split identifier. Author defined Unique identifier for a laboratory sample mean_length 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. Author defined 90 296 micrometer (micron) mean_width 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. Author defined 56 143 micrometer (micron) rs Spherical radius of apatite grains calculated based on mean width and mean length and measured in micrometers (microns). Author defined 33 80 micrometer (micron) 4He_nmol_g Measure of radiogenic 4He (helium) in nanomole/gram. Author defined 0.049 101.738 nanomole per gram (nmol/g) 4He_1sigma One sigma analytical error of the radiogenic 4He (helium) measurement, given in nanomole/gram. Author defined 0.001 0.128 nanomole per gram (nmol/g) U_ppm Measure of U (uranium) in parts per million. Author defined 1.3 310.5 parts per million (ppm) U_1sigma One sigma analytical error of the U (uranium) measurement, given in parts per million. Author defined 0.1 3.9 parts per million (ppm) Th_ppm Measure of Th (thorium) in parts per million. Author defined 3.0 213.5 parts per million (ppm) Th_1sigma One sigma analytical error of the Th (thorium) measurement, given in parts per million. Author defined 0.1 3.0 parts per million (ppm) Sm_ppm Measure of Sm (samarium) in parts per million. Author defined 2.9 143.1 parts per million (ppm) Sm_1sigma One sigma analytical error of the Sm (samarium) measurement, given in parts per million. Author defined 0.3 6.6 parts per million (ppm) eU Effective uranium concentration, a parameter that weights the decay of the two parents for their alpha productivity, computed as U + 0.235xTh. Author defined 3.4 311.9 raw_date_ma Raw date in millions of years (Farley and Stockli, 2002). Date has not been corrected for alpha ejection. Author defined 0.8 380.6 millions of years (Ma) Ft_corr Alpha ejection correction, which is the fraction of 4He alpha particles retained, and is calculated from grain dimensions and chemistry (Farley and Stockli, 2002). Author defined 0.56 0.80 Ft_corr_1sigma_pct One sigma error on the alpha ejection parameter, expressed in percentage. Author defined 7 23 percent corr_date_ma 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). Author defined 1.3 661.3 millions of years (Ma) corr_date_1sigma One sigma analytical uncertainty on date based on error propagation from measured quantities. Author defined 0.02 6.43 millions of years (Ma) analy_date Date of analysis given in month and year, YYYYMM Author defined 201412 201509 Date (YYYYMM) comments Comments about anomalous records which were excluded from age calculations in Lease, 2018 Author defined free text thermochronology_UThHe_zircon_revelationMtns_lease.csv Table with 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. Presented in a Comma Separated Value (CSV) formatted table. Author defined map_no Sample identifier used on maps, diagrams, and tables in publication Lease (2018). Author defined 1 16 lab Identifies the laboratory where analysis was performed. Author defined University of Colorado University of Colorado Thermochronology Research and Instrumentation Laboratory (TRaIL). Analyses performed by James R. Metcalf. Author defined University of Texas University of Texas (U-Th)/He Laboratory in Austin, Texas Author defined field_id 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. Author defined Unique identifier for a sample sample_id Concatenation of field_id and laboratory split identifier. Author defined Unique identifier for a laboratory sample mean_length 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. Author defined 146 528 micrometer (micron) mean_width 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. Author defined 60 153 micrometer (micron) rs Spherical radius of zircon grains measured in micrometers (microns). Author defined 39 88 micrometer (micron) 4He_nmol_g Measure of radiogenic 4He (helium) in nanomole/gram. Author defined 24.012 640.742 nanomole per gram (nmol/g) 4He_1sigma One sigma analytical error of the radiogenic 4He (helium) measurement, given in nanomole/gram. Author defined 0.022 1.221 nanomole per gram (nmol/g) U_ppm Measure of U (uranium) in parts per million. Author defined 316.8 7241.6 parts per million (ppm) U_1sigma One sigma analytical error of the U (uranium) measurement, given in parts per million. Author defined 5.3 235.0 parts per million (ppm) Th_ppm Measure of Th (thorium) in parts per million. Author defined 36.2 2745.5 parts per million (ppm) Th_1sigma One sigma analytical error of the Th (thorium) measurement, given in parts per million. Author defined 0.7 86.3 parts per million (ppm) Sm_ppm Measure of Sm (samarium) in parts per million. Author defined 0.4 197.1 parts per million (ppm) Sm_1sigma One sigma analytical error of the Sm (samarium) measurement, given in parts per million. Author defined 0.01 8.82 parts per million (ppm) eU Effective uranium concentration, a parameter that weights the decay of the two parents for their alpha productivity, computed as U + 0.235 x Th. Author defined 326.6 7886.8 raw_date_ma Raw date in millions of years (Reiners, 2005). Date has not been corrected for alpha ejection. Author defined 9.7 23.6 millions of years (Ma) Ft_corr Alpha ejection correction, which is the fraction of 4He alpha particles retained, and is calculated from grain dimensions and chemistry (Reiners, 2005). Author defined 0.71 0.87 Ft_corr_1sigma_pct One sigma error on the alpha ejection parameter, expressed in percentage. Author defined 7 12 percent corr_date_ma 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). Author defined 13.20 29.8 millions of years (Ma) corr_data_1sigma One sigma analytical uncertainty on date based on error propagation from measured quantities. Author defined 0.1 1.5 millions of years (Ma) analy_date Date of analysis given in month and year, YYYYMM. Author defined 201503 201510 Date (YYYYMM) thermochronology_fissonTrack_apatite_revelationMtns_lease.csv Table with 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. Presented in a Comma Separated Value (CSV) formatted table. Author defined map_no Sample identifier used on maps, diagrams, and tables in publication Lease (2018). Author defined 2 16 field_id 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. Author defined free text grain Numeric code assigned to a single apatite grain. The numeric code is unique for each sample (field_id). Author defined Sequential numeric value for each sample (field_id), ranging from 1 to 40. Ns Number of spontaneous tracks counted. Author defined 0 57 area Surface area of apatite grain in which tracks were counted. Author defined 0.00000874 0.0000485 cm^2, or centimeter squared U_Ca Ratio of 238Uranium / 43Calcium Author defined 0.0012614 1.4506 U_Ca_1sigma One sigma analytical error of 238Uranium/43Calcium ratio. Author defined 0.00009 0.24038 Dpar_um 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. Author defined 1.34 2.35 micrometer or micron Dper_um 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. Author defined 0.19 0.60 micrometer or micron U_ppm Uranium, in parts per million, measured using the laser ablation inductively couple plasma-mass spectrometry (LA-ICPMS) method (Donelick and others, 2005). Author defined 1 292 parts per million (ppm) Th_ppm Thorium, in parts per million, measured using the laser ablation inductively couple plasma-mass spectrometry (LA-ICPMS) method (Donelick and others, 2005) Author defined 2 1238 parts per million (ppm) Sm_ppm Samarium, in parts per million, measured using the laser ablation inductively couple plasma-mass spectrometry (LA-ICPMS) method (Donelick and others, 2005). Author defined 23 2264 parts per million (ppm) FT_age_ma Fission-track age calculated for the single apatite grain (Donelick and others, 2005). Author defined 0.0 129.9 millions of years (Ma) lower95CI_ma Lower 95th confidence interval fission-track age in millions of years (Donelick and others, 2005). Author defined 0.0 88.8 millions of years (Ma) upper95CI_ma Upper 95th confidence interval fission-track age in millions of years (Donelick and others, 2005). Author defined 2.8 937.6 millions of years (Ma) U.S. Geological Survey USGS ScienceBase Team Mailing and Physical

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Denver Colorado 80225 USA 1-888-275-8747 sciencebase@usgs.gov The U.S. Geological Survey, Alaska Science Center is the authoritative source of these data, distributed by ScienceBase (a USGS Trusted Digital Repository). 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. CSV Tabular data in CSV format; FGDC metadata in XML and HTML formats. https://doi.org/10.5066/P9ZNIHT7 None 20250526 U.S. Geological Survey, Alaska Science Center Mailing and Physical

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Anchorage Alaska 99508 USA 907-786-7000 gs-ak_asc_datamanagers@usgs.gov FGDC Content Standard for Digital Geospatial Metadata (CSDGM) FGDC-STD-001-1998