ON THE QUESTION OF DIFFUSION LOSS OF RADIOGENIC AND SPALLOGENIC RARE GASES FROM STONE METEORITES

Using a technique of specific solvents the rare gas contents of the main mineral fractions of stone meteorites were measured separately. In this way the diffusion loss of the radiogenic and spallogenic rare gases in 5 chondrites all of which had U-Th-He ages considerably below 4.5 billion years was studied. The results showed that in 4 of these meteorites all of which belonged to the UreyCraig group L, no diffusion losses occurred during the time of cosmic ray exposure. Only in one of the meteorites, i.e. Breitscheid, (group H) large diffusion losses of the cosmic-ray-produced /sup 3/He were found. Considerable losses of radiogenic /sup 4/He could be proved for the meteorites Breitscheid and Bruderheim. For the meteorite Breitscheid the loss of /sup 4/He seemed to be approximately a factor of 2 lower than that of /sup 3/He. (auth)