Thorium, Uranium and Lead Contents of Some Indian Zircons and Their Ages

A number of zircon separates from-various localities of India were analysed for their uranium, thorium and lead contents. Uranium and thorium were analysed by neutron activation, and lead by anodic stripping methods respectively. Thorium, uranium and lead were found to vary between 60-250, 60-900, 8-90 ppm, respectively. The Th/U ratios are found to be in conformity with the accepted values for granitic or pegmatiticzircon. The elemental abundances have been used to calculate their chemical ages and the values compared with those reported in literature. The ages obtained in this study range from 400-800 m.y. These ages are comparable with the previous reported values.