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U-Pb Isotopic Data and Ages of Zircon and Titanite from Rocks from the Yukon-Tanana Upland, Alaska

August 26, 2020

This data set contains 3 tables containing uranium-lead (U-Pb) isotopic data and crystallization ages of zircon and titanite from igneous, metamorphic, and sedimentary rocks collected from the Yukon-Tanana upland of eastern interior Alaska between 2013 and 2019. Bulk samples of igneous and metamorphic rocks were processed into concentrated mineral separates of zircon and (or) titanite 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. Bulk samples of sedimentary and metasedimentary rocks were processed into concentrated mineral separates of detrital zircon and analyzed by Apatite to Zircon, Inc. and GeoSep Services (GSS) using laser-ablation-inductively-coupled-plasma-mass spectrometry (LA-ICP-MS) techniques. The 2 data tables (geology_detritalZircon_easternAK_Jones.csv; geology_SHRIMPRGData_easternAK_Jones.csv) 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. A third table (geology_sampleSummary_easternAK_Jones.csv) reports sample locations, rock characteristics, and interpreted ages. The SHRIMP-RG data table (geology_SHRIMPRGData_easternAK_Jones.csv) also reports concentrations of selected trace elements measured in each grain.

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