NOBLE-GASES IN H-CHONDRITES AND POTENTIAL DIFFERENCES BETWEEN ANTARCTIC AND NON-ANTARCTIC METEORITES

Thirty-one Antarctic H-chondrites from the Allan Hills have been analyzed for their noble gases. Seven of the specimens contain solar gases; thirteen have a cosmic-ray exposure age around 8 Ma. Both fractions are as observed for H-chondrites from the rest of the world. Scrutiny of the data for "paired samples" yields a minimum number of 17 independent falls, with 6 falls required for the 8 Ma peak of exposure age. The distribution of exposure ages as well as that of radiogenic He-4 and Ar-40 yield no evidence that H-chondrites from the Allan Hills regions represent a mixture of populations that is different from that brought to moderate latitudes of the Earth in more recent times.