SEEMORE DOWNS 001

When found in Western Australia this meteorite was composed of several large fragments and four smaller pieces for a total known weight of 429 g. Seemore Downs may be an extreme member of the L or LL ordinary chondrites or may be derived from its own parent body with properties intermediate to both the L and LL parent bodies.

Previous parameters used to delimit the L/LL group from the L and LL groups include the fayalite molar percentage and the content of cobalt in kamacite. New studies utilizing cluster anaysis statistics on the minor and trace element data conclude that the L/LL meteorites are chemically more closely related to each other than they are to either the L or LL group. Furthermore, the enriched REE concentration and negative europium anomaly that are found only in the L/LL meteorites, easily distinguishes them from the other groups. The evidence is stronger for the existence of a separate L/LL, low total-Fe, chondritic parent body.

Other members of this newly recognized intermediate chondrite group include the L/LL3 Esperance, the L/LL4 Bjurböle and Cynthiana, the L/LL5/6 Sahara 97021, the L/LL6 Acfer 041, and several others. A few meteorites are only partially resolved into the L/LL group including the L/LL3 Inman, the L/LL5 Knyahinya and Qidong, and the L/LL6 Holbrook and Sultanpur. The specimen of Seemore Downs 001 shown above is an 8.9 g partially crusted fragment.

---