Quartz shielding of sub-10 μm zircons from radiation damage-enhanced Pb loss: An example from a metamorphosed mafic dike, northwestern Wyoming craton

► Used automated mineralogy and refined SIMS U-Pb geochronology. ► Date mafic dike zircons small as 5 μm in situ; U-Pb data define discordia array. ► Matrix zircons are discordant due to radiation damage-enhanced Pb loss. ► Zircons in unfractured quartz are concordant due to shielding from Pb loss. ► Document high-pressure, high-temperature event at ca. 1.75 Ga in NW Wyoming craton.