ANNEALING CHARACTERISTICS OF FISSION TRACKS IN MINERALS AND THEIR APPLICATIONS TO EARTH SCIENCES

The studies on thermal annealing of tracks stored in different minerals are carried out by track density as well as track length measurements. The average range of fission fragment in the minerals has been determined. It has been observed that the annealing of the tracks depend on their initial length and therefore on the charge of the incident ions. Thermal effect on fission fragments reveal that the shrinkage in range is accompanied by the reduction in number of tracks per unit area. The complete annealing data (i.e. experimental and geological annealing temperatures required to cause different degrees of track annihilation in different annealing eras, activation energy spectra etc.) of the ten minerals have been incorporated in the present report. The calibration curves and annealing vs optimum etch-time graphs have been constructed for their use in fission track geochronology. The annealing characteristics of the minerals coupled with their fission track ages help us to evaluate the cooling/thermal history and tectonic uplifts of the parent rocks. The versatile applications of track annealing phenomena are briefly discussed. © 1979.