Regensburg 2019 – wissenschaftliches Programm
KFM 14.36: Poster
Mittwoch, 3. April 2019, 16:00–18:30, Poster C
Pressure-induced amorphization of dynamically compressed and heated minerals by X-ray diffraction and electron microscopy — •Christoph Otzen1, Hanns-Peter Liermann1, and Falko Langenhorst2 — 1Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany — 2Institut für Geowissenschaften, Jena, Germany
Large planetary meteorite/asteroid impacts play a crucial role in the history of the Earth, traces of which can still be found in minerals today and provide important information about past impact events. The most significant impact indicator is the amorphization of many minerals and many studies have been performed to constrain the conditions for amorphization as a function of pressure and compression rate. The effects of temperature and grain sizes, however, have not yet been investigated accurately and in-situ, due to experimental limitations and the extreme conditions attained during shock compression.
In this study, we carried out dynamic compression experiments and simultaneously measured in-situ X-ray powder diffraction of abundant rock-forming minerals. We use membrane-driven diamond-anvil cells to rapidly compress the samples to high pressures and are in the process of developing a new setup for simultaneous pressure and temperature increase. We aim at creating the thermodynamic conditions that can be found in natural impacts in an effort to constrain the conditions for amorphization more precisely. We will present initial results of these diffraction experiments and the analyses on the recovered samples by transmission electron microscopy.