Question

Fission Track Dating Constants: λ"-1.55 125 x 10"。у'. Af = 8.46 × 10.17 yı:o-580.2 x 10'24 cm2. 235Upsv- 1/137.88 3. Muscovite from Val Grosina in the Swiss Alps was dated by the Rb-Sr, K-Ar, and fission-track methods. (Miller and Jäger, 1968, Earth Planet. Sci. Letters, 4:375-378). Rb-Sr date 252 Ma, K-Ar date 217 Ma p/p, 5x 10-3-9-6.2x lo" nc/cm2 Calculate the fission-track date of muscovite and interpret the differences between the dates obtained by different methods.

Answer 1

The age of sample can be obtained by using this equation, age = N × D_s/D_i × 6 × 10⁻⁸, in which N is the total neutron dose expressed as neutrons per square centimetre and Ds is the observed track density for spontaneous fission while Di is that for induced fission.