Fission tracks are ubiquitous crystal defects of ca. 10-20 um length in uranium-bearing solid materials (e.g. minerals). In nature they form by the spontaneous fission of U (mainly 238U), their number being primarily determined by the uranium concentration and the age of the investigated phase. With the help of chemical etching, fission tracks become observable by optical microscopy and their number is usually determined manually. The areal density of fission tracks as well as their length distribution is commonly used for dating geological processes such as volcanic eruptions, exhumation of mountain belts, oil/gas generation and landscape evolution. However, the robustness of the method has been questioned recently, leaving room for methodological development requiring high-tech analytical instrumentation.
Lecture in English.