A carbon-14 depth profile in the L5 chondrite Knyahinya

We report on a series of measurements of C-14 in samples of the L-chondrite Knyahinya, as a function of depth. The results show C-14 concentrations ranging from 37 to 58 dpm/kg. These measurements are compared to the levels of Ne-21, Be-10 and noble-gas ratios in this meteorite reported by Graf et al (1990). We also compare the C-14 data to the expected profile based on two sets of model calculations. The behavior of this radioisotope with depth is similar to that expected from the models, and good agreement with the profiles of other nuclides is also observed.