Isotopically anomalous nitrogen and carbon found in the carbonaceous chondrites Allende and Murchison can be attributed to the x-process nucleosynthesis, which produced, aside from the light elements D, Li, Be and B, appreciable quantities of 12C, 13C, 14N, 15N, 16O, 17O, 18O and so on during an intermediate stage in the early history of the solar system.
