Three dimensional (3-D) density structures for the lunar mascons beneath impact basins and its implication for the evolution of the moon

Abstract

Lunar mascons are thought to be caused by mantle uplift. We study lunar mascons to reveal their high-resolution 3D density structure based on the depth-weighting gravity inversion method. The inversion results show that mascons exhibit annular density anomalies, but the roots of mascons on the lunar nearside are shallower than those at the farside, which is consistent with the thicker crust at the lunar farside. Inner density heterogeneity for mascons is also observed in the density model, indicating evidence of the possible vertical and horizontal isostatic readjustment. Based on the density models, we suggest that the crustal asymmetry on the Moon observed in lunar basin thickness, size, and diameter is partly caused by mascon density heterogeneity located in the mantle that promoted mantle uplift after impact cratering, as observed in the recovered density models for lunar mascon.