<scp>SIMS U‐Pb</scp> dating of micro‐zircons in the lunar meteorites Dhofar 1528 and Dhofar 1627

Abstract About half of the lunar meteorites in our collections are feldspathic breccias. Acquiring geochronologic information from these breccias is challenging due to their low radioactive‐element contents and often polymict nature. We used high‐spatial‐resolution (5 μm) NanoSIMS (nanoscale secondary ion mass spectrometry) U‐Pb dating technique date micro‐zircons Dhofar 1528 1627. Three spots two zircon grains show a discordia with an upper intercept at 4354 ± 76 Ma lower 332 1407 (2 σ , MSWD = 0.01, p 0.91). 1627 define 3948 30 691 831 0.40, 0.53). Both samples likely experienced shock metamorphism caused by impacts. Based on clastic nature, lack recrystallization consistent Pb‐Pb dates zircons 1528, interpreted as crystallization age its Mg‐suite igneous precursor. Some poikilitic texture, matrix impact melt, so corresponds event, Imbrium basin‐forming event. These data first radiometric ages for demonstrate that situ (high spatial resolution) has potential extracting geochronological about activities events