40Ar/39Ar Isotopic Data and Ages for Rocks from the Yukon-Tanana Upland of Eastern Alaska and the Northern Aleutian Range of South-Central Alaska

This dataset contains 40Ar/39Ar isotopic data and ages for rocks from the Yukon-Tanana upland of eastern Alaska and the northern Aleutian Range of south-central Alaska. The entire sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis were conducted from 2013 to 2019 by the Mineral Resources Program of the U.S. Geological Survey (USGS). Legacy bedrock samples archived from earlier USGS field investigations were also analyzed in some cases. Hornblende, muscovite, and (or) biotite were extracted from bedrock samples of igneous and metamorphic rocks and analyzed at the University of Alaska Fairbanks Geochronology Laboratory in order to determine the 40Ar/39Ar age of each mineral phase. The data tables accompanying this data release report the resulting 40Ar/39Ar analytical data and interpreted ages for each mineral separated from a bulk rock sample.