Unveiling the subsurface extent of the lunar KREEP unit from geodynamic modeling.

Abstract

Introduction: The Moon has been suggested to have a highly asymmetric volcanic history, with at least three times more volcanic activity recorded on the nearside with respect to the farside [1]. One possible explanation to the asymmetry has been suggested to be the asymmetric distribution of subsurface Heat Producing Elements (HPE, i.e. Th, U, and K) [2]. However, the timeline and nature of a potential redistribution of HPE, during or after the lunar magma ocean (LMO) solidification, remains highly debated [3].

Here, we investigate the lateral distribution and concentration of HPE, testing various extents and enrichments of a putative KREEP-rich anomaly formed during or after LMO crystallization [3]. Modeled present-day surface heat flux is compared to observations to identify best-fit models of lunar interior.