Lunar trapped xenon

Evidence is presented for the presence in Apollo 16 light matrix breccias of trapped xenon which is isotopically similar to terrestrial xenon. This trapped component is predominantly released above 900 C, together with cosmic ray produced spallation gases. The relative abundances of Ar, Kr, and Xe are distinct from both solar and terrestrial patterns. Terrestrial-type xenon has so far been observed in both Apollo 14 and 16 breccias.