An acid-etch study of the Kapoeta achondrite: Implications for the 36Ar/38Ar ratio in the solar wind
Noble gases were measured in the Kapoeta achondrite by means of step-wise closed-system acid-etching with H2SO3. Isotopic ratios indicate that He, Ne and Ar are primarily solar in origin, although elemental abundance ratios indicate that the He and Ne have been significantly depleted relative to the argon. Xenon is dominated by a typical trapped meteoritic component, and the same is probably true for krypton. The initial 11% of the argon released from the sample by acid etching has a cumulative 36Ar/38Ar ratio of 5.58 +/- 0.03, indicating that the solar wind at some time in the past had a 36Ar/38Ar ratio significantly above previous values suggested for this ratio.