Shock metamorphism in plagioclase
2016-2019: Austrian Science Fund FWF V-505
Dr. Lidia PITTARELLO
Univ. Prof. Dr. Rainer ABART
Univ. Prof. Dr. Christian KOEBERL
Natural History Museum Vienna
Abstract: Plagioclase is the most abundant mineral phase in the crust of solid planetary bodies as one of the last phases to form during magmatic crystallisation. Nevertheless, little is known about its response to shock metamorphism in impact events, even if impacts between planetary bodies are considered an important process controlling the evolution of the Solar System and possibly life on the Earth. This project will fill a gap in our knowledge of shock metamorphic effects in minerals and will contribute to the understanding of the effect of impacts in the evolution of the crust of planetary bodies in the Solar System.
The main topics that will be investigated are:
- Correlation between the occurrence of planar features (PFs and PDFs) in plagioclase and its anorthite content.
- The crystallographic control in the transformation from crystalline plagioclase into maskelynite (shock-induced diaplectic glass).
- Element diffusion within plagioclase after partial transformation into diaplectic glass.
A series of natural (impact craters on Earth and meteorites) and experimental plagioclase-bearing shocked samples, covering the entire range of An contents and of different shock stages, will be investigated with different approaches, ranging from traditional petrography and geochemistry to new techniques, to develop a calibration for the evaluation of shock pressure.