The ophiolite rocks of Zermatt are an excellent natural laboratory to study processes during the formation, hydrothermal alteration and subduction of former oceanic crust of the Piemont ocean in the Alpine orogeny. The Piemont ocean was a slow spreading system, in which dykes of gabbros and basalt intruded the mantle rocks. These dykes experienced extensive alteration during seafloor metasomatism leading to rodingites and chlorite-rich rocks, followed by recrystallization during subduction-related metamorphism. Former Ti-rich basalt dikes in the peridotites are metamorphosed to Ti-clinohumite and Ti-chondrotite-rich rocks.
The aim of this project is to reconstruct the evolution of this peculiar rock types from the magmatic emplacement at the mid-ocean ridge, to the alteration during sea-floor metasomatism and Alpine recrystallization during subduction. A special focus is placed on the phase relations of Ti-rich minerals and accessory minerals.
The project will include fieldwork, petrographic characterization of thin sections, electron microprobe, infrared spectroscopy and laser ablation ICP-MS.
Advisors: Prof. Jörg Hermann, Prof. Daniela Rubatto, Dr. Francesca Piccoli
University: BE