Beryllium-10 contents of shergottites,nakhlites, and Chassigny

Accelerator mass spectrometry gives the following ¹⁰Be contents (dpm/kg) for the SNC meteorites: Shergotty, 13.0 ± 1.5 and 17.3 ± 2.7; Zagami, 18.6 ± 2.5 and 20.0 ± 3.2; ALHA 77005, 15 ± 3; EETA 79001A, 7.8 ± 1.1 and 6.3 ± 0.5; EETA 79001B, 8.5 ± 1.1; Nakhla, 19.7 ± 3.3; Lafayette, 18.1 ± 2.5; Governador Valadares, 25.6 ± 3.6; Chassigny, 20.5 ± 3.1. The ¹⁰Be contents of the NC meteorites indicate that significant accumulation of cosmogenic nuclides occurred in decimeter rather than planetary-size bodies. The agreement of the ³He, ²¹Ne, and ¹⁰Be exposure ages of the shergottites also supports small-body irradiation. A long terrestrial age for EETA 79001 appears unlikely.