VARELA Maria Eugenia
congresos y reuniones científicas
SEM-EDX AND ATEM STUDIES OF OLIVINITES FROM THE ANGRITE D?ORBIGNY.
HWANG S.L.; CHU, H-T; VARELA M.E.; YUI T.F.; SHEN P
Congreso; 75th Annual Meteoritical Society Meeting; 2012
Olivinites from the angrite D´Orbigny consist of milky greenish-white olivines of up to 8 mm in diameter. They have a chemical composition (Mg# [=Mg/(Mg+Fe)] = 0.90) very different from the precipitates that can possibly be derived from angrite parent melts. Therefore, they are usually considered "xenocrysts" [e.g.1-2]. However, they could be one of the oldest surviving building blocks of D?Orbigny . Here we present evidence about the phase assemblage and defect microstructures on a large olivinite using SEM-EDX and ATEM techniques, in order to gain some insight into the genesis of these particular phases.