Insights into the Petrogenesis of Lunar Basaltic Breccia Dominion Range (DOM) 18543

From the 2018-2019 Antarctic Search for Meteorites (ANSMET) season, eight polymict, basaltic lunar regolith breccias were recovered from the Dominion Range (DOM). This study examines DOM 18543,9, a clast-poor breccia (<10%) containing clasts of basalts, gabbros, impact melt breccias, 3-phase symplectites, and one microbreccia containing a FAN-derived, anorthositic granulite. All clasts and mineral fragments are set in a glassy matrix which contains glassy melt veins, pockets, and impact glass spherules. Pyroxene and olivine Fe/Mn systematics are consistent with a lunar origin. Pyroxenes are augites and pigeonites, olivines are predominantly fayalitic (Fa 85-99 ), and plagioclase is typically anorthitic (An 93-99 ). Pyroxene, ilmenite, and olivine compositions are consistent with derivation from a compositionally evolved, low-Ti basaltic magma and represent the relatively late stages of fractionation. Textural and geochemical characteristics are similar to those of the YAMM group indicating a potential shared source from an ancient, low-Ti, KREEP-poor lava flow in a mare terrane where feldspathic material is locally available. While some characteristics are shared with an unnamed crater within the Schickard crater, characterization of paired meteorites within the DOM clan, alongside cosmic ray exposure dating and integration of remote-sensing observations is required in order to refine the petrological framework of these recently discovered lunar samples.