Two basaltic magma types on the Moon

Abstract

This paper discusses two types of differentiation trend in the lunar basaltic magma, found in the Pre-Imbrium and Post-Imbrium basalt samples on the lunar nearside. The oldest basalt (4.23 Ga) in 14305 shows the calc-alkaline trend in the terrestrial basaltic magma. In contrast, the young (2.87 Ga) mare basalt NWA 773 shows the tholeiitic trend. This infers the physical and chemical condition of the pre- and post-Imbrium basaltic magmatism is distinct especially in the volatile-element abundance.