What nanostructures in crystals can tell us about our Earth’s history

Fabian Kohlmann, Department of Earth Science, UiB

Aud B - Friday May 11, 14.15

Abstract: Fission track dating is a radiometric dating method in geology, based on the spontaneous fission of uranium nuclei in a crystal lattice. During a spontaneous fission event two highly energetic fission fragments are released, which then create nano-damage trails in a mineral crystal’s lattice. The analysis of those tracks enables us to unravel the thermal histories of rocks and the evolution of our Earth’s surface. This technique can also be applied for the absolute dating of fast cooled rocks, tectonic processes, investigation of denudation histories, landscape evolutions and basin analysis. To improve the accuracy of this method the fundamental processes involved in the formation of fission tracks need to be better understood, as there are still many “unknown” factors regarding to the first few nanoseconds after a spontaneous fission of the uranium nucleus took place. In this presentation we show a study of artificially created fission tracks in apatite, mica and zircon, which were analysed by the means of Atomic Force Microscopy (AFM) and an introduction in how this technique is applied in Earth Sciences.