Mg‐Spinel Distribution in South Pole‐Aitken (SPA) Basin: Spatial Distribution, Geologic Context and Spectral Characterization

Abstract The spatial distribution of Mg‐spinel lithology at South Pole‐Aitken (SPA) basin is revealed by systematic mineralogical survey along the basin rings. We report Ingenii‐Thomson region as a Mg‐spinel anomaly, having the largest number of exposures based on newly identified and previously reported occurrences on the Moon. The timing of Mg‐spinel formation is constrained by using SPA impact as a key geological time marker. Post‐SPA origin of this lithology is favored in this region due to the general lack of pervasive Mg‐spinel occurrences along basin rings, being the deepest exposures of the pre‐SPA crust. Our detailed mineralogical analyses also highlight several detections of Mg‐spinel lithology exhibiting weak 1,000 nm absorption band, emphasizing the need for a detailed analysis of such locations. Collectively, these salient findings have important implications for understanding the compositional diversity of Mg‐spinel lithology, refinement of the formation models and determining the role of Mg‐spinel lithology in the lunar crustal evolution.