Abstract
The possibility of annealing of radiation damage in minerals and hence of track fading, always exists. This effect can be in response to a short time, higher temperature event, or be caused by prolonged annealing, at only a slightly elevated temperature during the geothermal history of earths crust. Track retention in minerals apatite, chlorite, biotite, phlogopite, muscovite, garnet, epidote and zircon have track retention over a wide range of temperatures (90–250°C), when we consider closing temperatures for fission track system. Further experiments have been made to determine the calibration curves relating track length shrinkage with track density reduction.
