Geochemical study of some howardites and polymict eucrites

Abstract

This study aims to characterize three howardites and three polymict eucrites based on rare earth and other trace element abundances. It is also aimed to identify possible carrier phase(s) of siderophile elements in polymict breccias and discuss their origin. Howardites (Y-7308 and Y-791573) and polymict eucrites (Y-75015, Y-74450 and Y792769) show lower siderophile pattern than those for Kapoeta but higher abundance than those in monomict eucrites. Their siderophile elemental ratios are non-chondritic, suggesting non-chondritic materials as projectiles (e.g., iron meteorites). This is consistent with our previous study that polymict eucrites contain a variety of non-chondritic projectiles. The current study implies that the HED parent body experienced multiple impacts of chemically variable projectiles.