Multiple Igneous Bodies for Nakhlites and Chassignites as Inferred from Olivine Cooling Rates using Calcium Zoning

Abstract: Nakhlites and chassignites are ultramafic cumulate rocks of clinopyroxene and olivine, respec-tively, considered to have been formed in a thick lava flow or shallow intrusion near the Martian surface [e.g., 1,2]. Although more than 100 Martian meteorites have been found so far, most of them are shergottites and only nine nakhlites and three chassignites are known (considering paired samples) [3]. In contrast to shergottites which show large variations in both mineralogy and ages, nakhlites an…