PRIMARY TRAPPED MELT INCLUSIONS IN OLIVINE IN THE OLIVINE-AUGITE-ORTHOPYROXENE UREILITE HUGHES 009

Abstract

We describe the first known occurrence of primary melt inclusions in a ureilite. The ureilite is Hughes 009, one of a small number of ureilites whose primary mineralogy is olivine-augite-orthopyroxene, rather than olivine-pigeonite. Hughes 009 has a coarse-grained, equilibrated texture typical of ureilites, and homogeneous primary mineral compositions: olivine — mg 87.3; augite — mg 89.2, Wo 37.0, Al2O3 = 1.6 wt.%; orthopyroxene — mg 88.3, Wo 4.9. It shows only limited secondary reduction effects and no petrographically recognizable carbon phases, which indicates that its original carbon content was lower than in most ureilites.