REE-bearing sulfide in Bishunpur (LL3.1), a highly unequilibrated ordinarychondrite

This is a report of the first unambiguous discovery of rare earth elements (REE) in iron sulfide (FeS) in an ordinary chondrite, The content and the p attern of REE as well as the reduced state of the chondrules with the REE-c ontaining sulfide suggest that the sulfide inside the Bishunpur (LL3.1) cho ndrules is of igneous origin, formed during crystallization of the chondrul e melts. The similarities in the content and the pattern of REE between cho ndrule sulfide and matrix sulfide in Bishunpur indicate a genetic relations hip. The presence of igneous sulfide inside chondrules provides constraints on the ambient nebular temperature and the duration of chondrule formation . The results of this study allow, on the basis of REE content and pattern, discrimination of igneous sulfide from condensate and secondary sulfide in chondrites and other interplanetary materials. (C) 2000 Elsevier Science B .V. All rights reserved.