This data set contains uranium–lead (U-Pb) isotopic data and ages, hafnium (Hf) isotope data, and trace element concentrations of zircon from igneous rocks collected from the Darby Mountains area of the Seward Peninsula, Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted in 2017. The data tables accompanying this data release report the isotopic composition of U and thorium (Th) measured in each grain, ratios of 207Pb and 206Pb and 235U and 238U, and the age of each grain, plus trace element abundances from the same ablated aliquot, including phosphorus (P), vanadium (V), strontium (Sr), high field strength elements (HFSE), and rare earth elements (REE). Reported Hf (and lutetium, Lu) isotope data includes 176Hf/177Hf, 176Lu/177Hf, and 178Hf/177Hf ratios, calculated epsilon Hf values, and age-corrected isotope ratios and epsilon values.

This dataset contains U-Pb isotopic data and ages, Hf isotope data, and trace element concentrations of zircon from igneous rocks collected from the western Alaska Range of south-central Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2011 to 2013. We also analyzed portions of remainders of previously collected igneous bedrock samples from the USGS archive, allowing expansion of the dataset to include igneous bodies that were not sampled during 2011–2013 field work or were outside the area of focused project field work. Zircon was obtained from these igneous rocks to determine the crystallization age for the bedrock samples. The data tables accompanying this data release report the isotopic composition of uranium (U) and thorium (Th) measured in each grain, ratios of three isotopes of lead (208Pb, 207Pb, and 206Pb), two isotopes of uranium (235U and 238U), one isotope of thorium (232Th), and the age of each grain, plus trace element abundances from the same ablated aliquot, including P, V, Sr, high field strength elements (HFSE), and rare earth elements (REE). Reported Hf (and Lu) isotope data includes 176Hf/177Hf, 176Lu/177Hf, and 178Hf/177Hf ratios, calculated epsilon Hf values, and age-corrected isotope ratios and epsilon values.

This dataset contains U-Pb isotopic data and ages, Hf isotope data, and trace element concentrations of zircon from igneous rocks collected from the western Alaska Range of south-central Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2011 to 2013. We also analyzed portions of remainders of previously collected igneous bedrock samples from the USGS archive, allowing expansion of the dataset to include igneous bodies that were not sampled during 2011–2013 field work or were outside the area of focused project field work. Zircon was obtained from these igneous rocks to determine the crystallization age for the bedrock samples. The data tables accompanying this data release report the isotopic composition of uranium (U) and thorium (Th) measured in each grain, ratios of three isotopes of lead (208Pb, 207Pb, and 206Pb), two isotopes of uranium (235U and 238U), one isotope of thorium (232Th), and the age of each grain, plus trace element abundances from the same ablated aliquot, including P, V, Sr, high field strength elements (HFSE), and rare earth elements (REE). Reported Hf (and Lu) isotope data includes 176Hf/177Hf, 176Lu/177Hf, and 178Hf/177Hf ratios, calculated epsilon Hf values, and age-corrected isotope ratios and epsilon values.

This dataset contains U-Pb isotopic data and ages, Hf isotope data, and trace element concentrations of zircon from igneous rocks collected from the Yukon-Tanana Upland, eastern Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2013 to 2019. Zircon was obtained from these igneous rocks to determine the crystallization age for the bedrock samples. The data tables accompanying this data release report the composition of uranium (U) and thorium (Th) measured in each grain, ratios of three isotopes of lead (206Pb, 207Pb, 208Pb), two isotopes of uranium (235U and 238U), and one isotope of thorium (232Th), as well as the age of each grain, plus trace element abundances from the same ablated aliquot, including P, V, Sr, high field strength elements (HFSE), and rare earth elements (REE). Reported Hf (and Lu) isotope data includes 176Hf/177Hf, 176Lu/177Hf, and 178Hf/177Hf ratios, calculated epsilon Hf values, and age-corrected isotope ratios and epsilon values.

This data set contains U-Pb isotopic data and ages, Hf isotope data, and trace element concentrations of zircon from igneous rocks collected from the western Alaska Range of south-central Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2011 to 2013. We also analyzed portions of remainders of previously collected igneous bedrock samples from the USGS archive, allowing expansion of the dataset to include igneous bodies that were not sampled during 2011–2013 field work or were outside the area of focused project field work. Zircon was obtained from these igneous rocks to determine the crystallization age for the bedrock samples. The data tables accompanying this data release report the isotopic composition of uranium (U) and thorium (Th) measured in each grain, ratios of three isotopes of lead (208Pb, 207Pb, and 206Pb), two isotopes of uranium (235U and 238U), one isotope of thorium (232Th), and the age of each grain, plus trace element abundances from the same ablated aliquot, including P, V, Sr, high field strength elements (HFSE), and rare earth elements (REE). Reported Hf (and Lu) isotope data includes 176Hf/177Hf, 176Lu/177Hf, and 178Hf/177Hf ratios, calculated epsilon Hf values, and age-corrected isotope ratios and epsilon values.

This data set contains U-Pb isotopic data and ages, Hf isotope data, and trace element concentrations of zircon from igneous rocks collected from the Yukon-Tanana Upland, eastern Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2013 to 2019. Zircon was obtained from these igneous rocks to determine the crystallization age for the bedrock samples. The data tables accompanying this data release report the composition of uranium (U) and thorium (Th) measured in each grain, ratios of three isotopes of lead (206Pb, 207Pb, 208Pb), two isotopes of uranium (235U and 238U), and one isotope of thorium (232Th), as well as the age of each grain, plus trace element abundances from the same ablated aliquot, including P, V, Sr, high field strength elements (HFSE), and rare earth elements (REE). Reported Hf (and Lu) isotope data includes 176Hf/177Hf, 176Lu/177Hf, and 178Hf/177Hf ratios, calculated epsilon Hf values, and age-corrected isotope ratios and epsilon values.

This Division of Geological & Geophysical Surveys (DGGS) Raw Data File presents U-Pb geochronology and Lu-Hf isotopic compositions, age-dating results, and additional trace-elemental composition of zircons from four granitoids sampled during investigations by DGGS geologists in the western Alaska Range and the Talkeetna Mountains. The purpose of the Lu-Hf and U-Pb isotopic study was to better understand the Jurassic through early Tertiary magmatic and tectonic evolution of the Alaska Range and the significance of that magmatism for the formation of metallic mineral deposits. The U-Pb isotopic data also serve to further refine the crystallization age of plutons, which were previously ambiguous in 40Ar/39Ar geochronology studies.

LA-ICP-MS uranium lead geochronologic data of zircon from igneous and meta-igneous rocks in the Chena project area, Circle, Big Delta, and Eagle quadrangles, Alaska, Raw Data File 2025-14, provides uranium-lead (U-Pb) geochronologic data from single zircon spots, analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Alaska Division of Geological & Geophysical Surveys (DGGS) staff collected zircon data from 22 igneous and meta-igneous rock samples, primarily collected during the 2023 field season, to support the Earth Mapping Resources Initiative (Earth MRI) Chena project. Two samples were analyzed to support geologic interpretation in the Mount Harper (2022) project area. Crystallization age data are organized in the age summary data table with our interpreted crystallization ages, sample location information, and sample descriptions. The zircon grain data table contains isotopic and elemental data for each zircon spot analyzed. Both tables have accompanying data dictionaries. These data and report are available from the DGGS website: http://doi.org/10.14509/31553.

This U.S. Geological Survey (USGS) data release accompanies planned publication ‘Geochemistry and radiogenic isotopes constrain the mantle source region of the Mountain Pass Intrusive Suite, California' and planned data release 'Whole-rock geochemical and isotopic data for the Mountain Pass Intrusive Suite, California'. The data release includes laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) Lu-Hf zircon data for zircons separated from eight samples in the Mountain Pass Intrusive Suite. The U-Pb geochronology and age interpretations for this set of samples is published in Watts et al. (2022). The samples were analyzed to investigate the mantle source region and paleotectonic setting for the Mountain Pass Intrusive Suite.