U-Pb Ages, Hafnium Isotope Ratios, and Trace Element Concentrations by Laser-Ablation Split Stream (LASS) Analysis of Igneous Zircons from the Western Alaska Range

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.