Abstract
Fission track geochronology of 7 samples of apatite found at Borra Mine, Vishakhapatnam district, has been described. The mineral is widely disseminated as an accessory constituent in large variety of rocks and fission tracks in them can be readily etched. The tracks are etched in conc. HNO3 and annealed in one hour at 400°C. Extrapolation of the experimentally determined temperatures for annealing suggests that a temperature of 170°C for one million year will erase all the tracks in the mineral. An absolute age of (456±4.7 m.y.) has been determined for the above mentioned district. The results have been compared with other minerals.
