These results show that electron microprobe chemical dating of uraninite has substantial promise as a reconnaissance tool for the geochronology of young granitic rocks.
The electron microprobe work also reveals substantial chemical complexity within uraninite that must be taken into account.
Radiocarbon dating would be most successful if two important factors were true: that the concentration of carbon-14 in the atmosphere had been constant for thousands of years, and that carbon-14 moved readily through the atmosphere, biosphere, oceans and other reservoirs—in a process known as the carbon cycle.
In the absence of any historical data concerning the intensity of cosmic radiation, Libby simply assumed that it had been constant.
The analyzed crystal displays a texturally and chemically distinctive core and rim that suggests episodic growth.