Dating zircon by combined use of fission and alpha tracks

Abstract

A new approach to dating zircon by combining fission and alpha tracks is described. In this method (alpha track method), spontaneous fission tracks in a sample are counted routinely and alpha tracks originating from the sample are counted on a plastic track detector. Uranium content of the sample is monitored based on the alpha track density and the detection time. Radioactive equilibrium and equal Th/U ratios among samples are assumed. A comparison between the conventional fission track method and the alpha track method has been made using age standard and other zircon samples. The results suggest that the alpha track method provides acceptable dating results when internal zircon surfaces are used for track counts. The alpha track method should be beneficial to those who do not have close access to neutron irradiation facilities.