M.S. Wang, E.S. Michlovich, S. Vogt, M.E. Lipschutz

Proceedings NIPR Symposium Antart. Meteorites 7 (1994) 144-149

Three ordinary chondrites from the Yamato Mountains (Y) region of Antarctica contain cm-sized igneous inclusions being studied by a consortium. RNAA data for the labile elements Ag, Bi, Cd, Cs, Ga, In, Rb, Sb, Se, Te, Tl and Zn, and refractory Au and U in the L6 hosts of Y-75097 and Y-793241 indicate that each experienced at least one preterrestrial, high-temperature episode. This heating occurred during formation of the igneous inclusions and/or as a result of the severe shock that affected most equilibrated L chondrites. Cosmogenic 720 ka 26Al, and 301 ka 36Cl (which are determined by AMS) in metal from these two meteorites and nominal terrestrial ages (based on 36Cl) hint that the L6 chondrites are not paired but are inconclusive in this regard. RNAA data for the H chondrite host of Y-794046 generally, resemble those of other H4-6 chondrites: its contents of cosmogenic radionuclides in general, and its 36Cl content, in particular, correspond to a nominal terrestrial age of +- 60 ka.