Uredelgase im Meteoriten Breitscheid

Abstract

Primordial rare gases have been found in the chondrite Breitscheid, which shows like Pantar light and dark regions. The primordial rare gases are only to be found in the dark portions; they amount to 179·10-6 cm3 STP/g helium and 221·10-8 cm3 STP/g neon. The isotopic compositions of these primordial rare gases have been determined by subtraction of the amounts of the radiogenic and cosmic ray produced rare gases measured in the light portions. Possible alterations of the isotopic abundances of the primordial rare gases in the time interval between the end of the nucleosynthesis and their capture in the meteoritic matter are discussed. The radiogenic helium age has now been determined to be 1.63·109 years.