Isotopic composition of the rare gases in the Fayetteville meteorite

The abundance pattern of the rare gases in the dark phase of the Fayetteville meteorite was found to be similar to that of the Pesyanoe and other meteorites rich in primordial rare gases. The light phase of the Fayetteville meteorite contains much smaller amounts of rare gases and is characterized by the presence of radiogenic Ar40 and cosmogenic Ne21, Ne22, etc. Both dark and light phases contain an excess of radiogenic Xe129 relative to the earth's atmosphere; the light phase contains an excess of fissiogenic xenon isotopes relative to the dark phase of the meteorite.