A Comparison of the Noble Gases in Three Meteorite Specimens Labeled Springfield

The abundance and isotopic composition of the noble gases were measured in three Spring-field specimens identified by the Denver Museum of Natural History with numbers 7029, 379.13 and 6040. The latter specimen contains more cosmogenic noble gas isotopes than the other two specimens and the abundance pattern of trapped noble gases in specimen 6040 is distinct from that in the other two specimens. Specimen 7029 contains about seven times as much radiogenic 40Ar and about four times as much radiogenic 129Xe as does specimen 379.13. These results indicate that the three specimens did not come from a single meteoroid.