Evidence for a non-cosmogenic implanted ¹⁴C component in lunar samples

Experiments to determine if the presence could be confirmed of excess ¹⁴C implantation in lunar soils and a rock surface sample were undertaken. Stepwise HF etchings of near-surface lunar soil 73221, collected from 0 to 0.5 cm depth and surface soil 10084, and a sample of surface scrapings from rock 68815 released appreciable amounts of ¹⁴C. Considering the amount of material dissolved, we find that the amounts of ¹⁴C released are significantly in excess of the amounts that would be necessary for both galactic and solar cosmic-ray-produced ¹⁴C, even for the very surface. Further, there is an excess of ¹⁴C released compared to deeper samples of rock and soil, based on our analyses of subsurface soils (73241 and 73261) from the same trench location of 73221, and earlier studies of ¹⁴C in rock 68815[1]. Based on the observed release pattern of ¹⁴C, we estimate that the excess ¹⁴C in the lunar surficial samples may be released from depths of up to several microns. We conclude that this is an implanted solar component.