RARE-EARTH ELEMENTS AND THE PETROGENESIS OF AUBRITES

REE measurements in the Bishopville aubrite confirm that oldhamite (CaS) is the dominant REE carrier, while most other phases, including the major silicates, are extremely REE-depleted. In oldhamite, a variety of REE patterns are observed, which could not have been produced during crystallization from a single fractionating magma. Although the aubrites have clearly undergone igneous processing, oldhamite (which is highly refractory) may be a relict phase . In this case, whole-rock REE data cannot provide information on the igneous evolution of these meteorites.