Fission-Track Method of Dating

The rate of uplift of the Transantarctic Mountains has been measured by the fission-track method which is briefly reviewed in Appendix 15.7.1 and was described in detail by Faure and Mensing (2005). The fission-track method is well snited for this purpose because uranium-bearing ntinerals (e.g., apatite) retain fission tracks only after the ntinerals have cooled to the track-retention temperature which for apatite is 60°C (Gleadow and Fitzgerald 1987). 

The interpretation of fission-track dates of apatite at increasing depths in a section of stable continental crust in Fig. 15.14 is based on the effect of temperature on the retention of fission tracks. This criterion is used to define three zones with increasing depth below the surface (Gleadow and Fitzgerald 1987)  

The complete retention zone extends from the surface to a depth of 1.8 km where a normal geothermal 

The partial annealing zone lies between depths of 1.8 and 4.2 km where the temperature rises from 60°C at 1.8 km to 130°C at 4.2 km. In this temperature interval the retention of fission tracks by apatite decreases with increasing temperature which means that the fission-track dates decrease with depth and approach 0 Ma at 4.2 km (130°C). 

In the total annealing zone at temperatures greater than 130°C and at depths greater than 4.2 km, apatite 

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