A. J. Gawronska , C. L. McLeod, M. Loocke, B. Shaulis

Basaltic magmatism is fundamental to planetary evolution, and continues to be studied in depth on Earth. Terrestrial studies indicate that basaltic magmatic systems are generally comprised of a series of batches with distinct compositions, which can be stored at depth within crystal frameworks, creating mushes. The crystal cargos of magmas erupted from such systems record evidence of the mush environment from which they crystallized, and the processes that worked to mobilize them. Here, we investigated if and how this relates to extraterrestrial magmatic systems by studying the textures and compositions at the crystal scale of basaltic samples collected during the Apollo missions. We found that four out of six samples studied here contain cargos that have reaction textures and reverse zoning, which are interpreted here as denoting an antecrystic origin. Specifically, pyroxene cargos in 10057, 12043, 15085, and 70017 contain grains that are sieved, resorbed, and broken down into symplectite, alongside grains that do not record such disequilibrium textures. The same pyroxene grains often record elevated trace element contents and/or reverse zoning in Mg and Cr relative to other grains, suggesting distinct petrogenetic histories. These four samples additionally contain feldspars reversely zoned in elements like An and Sr alongside grains normally zoned in these elements, indicating the existence of multiple population as a result of changing melt conditions. The textures and chemistries seen in the four samples are consistent with generation in a system whose architecture includes distinct magma lenses where magmas were stored as mushes, and may have been transported between lenses via porous flow and mobilized by influx of hot, primitive magma. Future work should evaluate individual lunar magmatic systems in greater detail to investigate the influence of these processes further.