¹S. R. Burnette, ¹K. L. Donaldson Hanna, ¹A. Dove, ²J. M. Sunshine, ³L. Santori, ⁴S. N. Valencia
Journal of Geophysical Research: Planets, 131, e2026JE009717
Open Source Link to Article [DOI: 10.1029/2026JE009717]

¹University of Central Florida, Orlando, FL, USA
²University of Maryland, College Park, MD, USA
³Purdue University, Lafayette, IN, USA
⁴University of Maryland College Park/NASA Goddard Space Flight Center, Greenbelt, MD, USA
Published by arrangement with John Wiley & Sons

Lunar “red spots” have been inferred to be regions of extrusive silicic volcanism based on the analysis of remote sensing observations that suggest S⁢i⁢O2$$-rich, FeO-poor composition and morphologies similar to terrestrial silicic domes. Outstanding, however, is the formation mechanism of these features, which can be constrained based on the mineralogical and elemental composition of the volcanic silicic features. Previous studies have shown an inverse correlation between mafic content and single scattering albedo, which can be used to estimate the silica content through Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) observations. Here, we present single scattering albedo maps of the nearside silicic sites (i.e., Gruithuisen domes, Mairan domes, Lassell Massif, and Hansteen Alpha) and characterize the variation across each volcanic construct and between sites to estimate their relative S⁢i⁢O2$$ contents, which, in turn, aids in determining the type of rocks making up these volcanic features. We find that the average single scattering albedos of the nearside silicic sites are similar among sites and are notably lower than single scattering albedo for the farside silicic site, the Compton Belkovich Volcanic Complex (CBVC). Our results therefore suggest that the nearside silicic sites may be intermediate in silicic composition, indicating a difference in formation mechanism from CBVC, or their highly silicic composition has been contaminated by mafic material via mare ejecta, intrusion into a pre-existing mafic crust, or simultaneous eruption of mafic and silicic magmas.