A new 1.3 aeon‐young achondrite

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Abstract
The 40Ar/39Ar age of Governador Valadares, a newly identified Nakhlite‐achondrite, has been determined to be 1.32 ±.04 × 109 yrs. The K‐Ar age and cosmic ray exposure age of Governador Valadares is essentially identical to analogous ages for the two other known Nakhlite‐achondrites and to Rb‐Sr ages determined for Nakhla. These data suggest that all three known meteorites of this class were derived from the same parent body by a common event, and confirm that Governador Valadares is a member of this class. The most probable heat source for producing such meteorites may be collisional melting of a portion of the parent body. Nakhlites may represent a rare phenomenon and may not be at all representative of the surface of their parent body.