This dataset contains U-Pb isotopic data and associated ages of detrital zircon from sedimentary and metasedimentary rocks collected from southwestern Alaska and from the Yukon-Tanana upland and environs of eastern interior Alaska and western Yukon, Canada. The samples were collected as part of geological mapping and research conducted from 1996 to 2021 and funded by the Mineral Resources Program of the U.S. Geological Survey. Detrital zircon grains were separated and analyzed by four different laboratories: U.S. Geological Survey laboratories in Denver, Colorado; Apatite to Zircon, Inc. (A2Z); GeoSep Services (GSS); and the University of British Columbia. All analyses were conducted between 2007 and 2021 using laser-ablation-inductively-coupled-plasma-mass spectrometry (LA-ICP-MS) techniques.

This data set contains U-Pb isotopic data and associated ages of detrital zircon from sedimentary and metasedimentary rocks collected from southwestern Alaska and from the Yukon-Tanana upland and environs of eastern interior Alaska and western Yukon, Canada. The samples were collected as part of geological mapping and research conducted from 1996 to 2021 and funded by the Mineral Resources Program of the U.S. Geological Survey. Detrital zircon grains were separated and analyzed by four different laboratories: U.S. Geological Survey laboratories in Denver, Colorado; Apatite to Zircon, Inc. (A2Z); GeoSep Services (GSS); and the University of British Columbia. All analyses were conducted between 2007 and 2021 using laser-ablation-inductively-coupled-plasma-mass spectrometry (LA-ICP-MS) techniques.

This data set contains two data sets. One data set is of U-Pb isotopic data and associated ages of detrital zircon grains from 16 sedimentary and metasedimentary rocks from the western Alaska Range, Livengood area and Seward Peninsula, Alaska. Two samples were collected from the York Mountains area of the Seward Peninsula of western Alaska. Three samples were collected from the Livengood quadrangle of central Alaska. Eleven samples were collected from the western Alaska Range of south-central Alaska. Detrital zircon grains from each of the sixteen 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. The second data set contains fossil identifications and age assignments from a select sedimentary rock from the western Alaska Range of south-central Alaska. Fossils were identified by visual inspection. All samples were collected as part of geological mapping research conducted between 1984 and 2014 and funded by the Mineral Resources Program of the U.S. Geological Survey.

From 2017-2019, framework metallogenic studies were completed in the eastern Yukon-Tanana upland in eastern Alaska. Numerous previously undated plutons known or suspected to contain components of porphyry, epithermal, and intrusion-related gold systems and associated deposit types were sampled for age and zircon trace element determinations between the Black Mountain area and the Yukon border, north of the Tanana River and south of the Yukon River. A collection of 54 samples were collected by Douglas Kreiner (USGS, Alaska Science Center). Zircon grains were separated from each sample. The samples were examined by U-Pb analysis by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) in a USGS laboratory in Denver, CO. The samples contain evidence of several discrete periods of magmatic activity, with concordant zircon dates that range from ca. 53.3-2727 Ma. The bulk of analyzed samples are between ca. 68-72 Ma. Other specific periods of magmatism based on zircon dates range from ca. 55 Ma, ca. 100-112 Ma, ca. 130 Ma, and ca. 180-211 Ma. The ca. 340-365 Ma dates are likely inherited from host rocks that were previously unidentified in the field area but are known in the regional framework geology. Archean and Proterozoic zircon dates are not common, but likely represent inheritance from sedimentary and metasedimentary protoliths from the region.

From 2017-2019, framework metallogenic studies were completed in the eastern Yukon-Tanana upland in eastern Alaska. Numerous previously undated plutons known or suspected to contain components of porphyry, epithermal, and intrusion-related gold systems and associated deposit types were sampled for age and zircon trace element determinations between the Black Mountain area and the Yukon border, north of the Tanana River and south of the Yukon River. A collection of 54 samples were collected by Douglas Kreiner (USGS, Alaska Science Center). Zircon grains were separated from each sample. The samples were examined by U-Pb analysis by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) in a USGS laboratory in Denver, CO. The samples contain evidence of several discrete periods of magmatic activity, with concordant zircon dates that range from ca. 53.3-2727 Ma. The bulk of analyzed samples are between ca. 68-72 Ma. Other specific periods of magmatism based on zircon dates range from ca. 55 Ma, ca. 100-112 Ma, ca. 130 Ma, and ca. 180-211 Ma. The ca. 340-365 Ma dates are likely inherited from host rocks that were previously unidentified in the field area but are known in the regional framework geology. Archean and Proterozoic zircon dates are not common, but likely represent inheritance from sedimentary and metasedimentary protoliths from the region.

This data release contains two datasets. One dataset is of U-Pb isotopic data and associated ages of detrital zircon grains from 16 sedimentary and metasedimentary rocks from the western Alaska Range, Livengood area and Seward Peninsula, Alaska. Two samples were collected from the York Mountains area of the Seward Peninsula of western Alaska. Three samples were collected from the Livengood quadrangle of central Alaska. Eleven samples were collected from the western Alaska Range of south-central Alaska. Detrital zircon grains from each of the sixteen 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. The second dataset contains fossil identifications and age assignments from a select sedimentary rock from the western Alaska Range of south-central Alaska. Fossils were identified by visual inspection. All samples were collected as part of geological mapping research conducted between 1984 and 2014 and funded by the Mineral Resources Program of the U.S. Geological Survey.

This data release contains two datasets. One dataset is of U-Pb isotopic data and associated ages of detrital zircon grains from 16 sedimentary and metasedimentary rocks from the western Alaska Range, Livengood area and Seward Peninsula, Alaska. Two samples were collected from the York Mountains area of the Seward Peninsula of western Alaska. Three samples were collected from the Livengood quadrangle of central Alaska. Eleven samples were collected from the western Alaska Range of south-central Alaska. Detrital zircon grains from each of the sixteen 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. The second dataset contains fossil identifications and age assignments from a select sedimentary rock from the western Alaska Range of south-central Alaska. Fossils were identified by visual inspection. All samples were collected as part of geological mapping research conducted between 1984 and 2014 and funded by the Mineral Resources Program of the U.S. Geological Survey.

This data set contains U-Pb isotopic data and ages of zircon and titanite from igneous and metamorphic rocks collected from the western Alaska and northern Aleutian Range of south-central Alaska. The data sets also contain U-Pb isotopic data and ages of detrital zircon from sedimentary and metasedimentary rocks collected in the same region but also from the Taylor and Wood River Mountains of southwestern Alaska. The entire sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2004 to 2019 and funded by the Mineral Resources Program of the U.S. Geological Survey (USGS). Zircon and (or) titanite were obtained from igneous and metamorphic rocks to determine the crystallization age and (or) age of metamorphism for the bedrock samples. Bulk rock samples were processed into concentrated mineral separates in USGS laboratories in Denver, Colorado, or by Apatite to Zircon, Inc. (A2Z) and analyzed by USGS research scientists at the Stanford-USGS Sensitive High Resolution Ion Microprobe with Reverse-Geometry (SHRIMP-RG) at Stanford University. Detrital zircon grains were obtained from samples of sedimentary and metasedimentary rocks to determine depositional age and sediment sources. Detrital zircon grains were separated from bulk bedrock samples and analyzed at one of three different laboratories [University of British Columbia (UBC, 2004 to 2006), at A2Z (2006 to 2009), and GeoSep Services (GSS, 2015 to 2019)] using laser-ablation-inductively-coupled-plasma-mass spectrometry (LA-ICP-MS) techniques. The data tables accompanying this data release report the isotopic composition of uranium (U) and thorium (Th) measured in each grain, ratios of two isotopes of lead (207Pb and 206Pb) and two isotopes of uranium (235U and 238U), and the age of each grain. The SHRIMP-RG data table also reports concentrations of selected trace elements measured in each grain.

This data set contains U-Pb isotopic data and ages of zircon and titanite from igneous and metamorphic rocks collected from the western Alaska and northern Aleutian Range of south-central Alaska. The data sets also contain U-Pb isotopic data and ages of detrital zircon from sedimentary and metasedimentary rocks collected in the same region but also from the Taylor and Wood River Mountains of southwestern Alaska. The entire sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2004 to 2019 and funded by the Mineral Resources Program of the U.S. Geological Survey (USGS). Zircon and (or) titanite were obtained from igneous and metamorphic rocks to determine the crystallization age and (or) age of metamorphism for the bedrock samples. Bulk rock samples were processed into concentrated mineral separates in USGS laboratories in Denver, Colorado, or by Apatite to Zircon, Inc. (A2Z) and analyzed by USGS research scientists at the Stanford-USGS Sensitive High Resolution Ion Microprobe with Reverse-Geometry (SHRIMP-RG) at Stanford University. Detrital zircon grains were obtained from samples of sedimentary and metasedimentary rocks to determine depositional age and sediment sources. Detrital zircon grains were separated from bulk bedrock samples and analyzed at one of three different laboratories [University of British Columbia (UBC, 2004 to 2006), at A2Z (2006 to 2009), and GeoSep Services (GSS, 2015 to 2019)] using laser-ablation-inductively-coupled-plasma-mass spectrometry (LA-ICP-MS) techniques. The data tables accompanying this data release report the isotopic composition of uranium (U) and thorium (Th) measured in each grain, ratios of two isotopes of lead (207Pb and 206Pb) and two isotopes of uranium (235U and 238U), and the age of each grain. The SHRIMP-RG data table also reports concentrations of selected trace elements measured in each grain.

This dataset contains U-Pb isotopic data and associated ages of zircon grains from 27 sedimentary samples and one volcanic ash sample from the Cretaceous Torok and Nanushuk Formations. Seven samples were collected from outcrop and 21 samples were collected from archived core material from oil exploration wells on the North Slope of Arctic Alaska. Zircon grains were analyzed at the University of California, Santa Barbara (UCSB) between 2013 and 2018 using laser-ablation inductively coupled plasma mass spectrometry (LA-ICPMS) techniques. The study was funded by the Energy Resources Program of the U.S. Geological Survey (USGS).