ARGON-37, ARGON-39, AND TRITIUM RADIOACTIVITIES IN THE HAVERÖ METEORITE

The ³⁷Ar and ³⁹Ar radioactivities were measured in a dissolved and in a melted sample of Haverö. The ³⁷Ar in the metal was 12.4 ± 2.6 dpm/kg (Fe + Ni). The ³⁹Ar in the metal was 49.3 ± 5.5 dpm/kg (Fe + Ni). The ³⁷Ar activity is within 30 percent of that in the Lost City meteorite, while the ³⁹Ar activity is a factor of two higher than in Lost City. The similarity in the ³⁷Ar activities of the metal of the two meteorites indicates that these two bodies had similar preatmospheric sizes. The higher ³⁹Ar activity in the metal of Haverö indicates that the aphelion of Haverö's orbit was at least 4.3 A.U. The ³H radioactivity in Haverö was measured to be 415 ± 30 dpm/kg. The ³H activity combined with the ³He content gives a ³He/2³H exposure age for Haverö of (29.5 ± 2.5) X ⁶10 years.