The Antrona ophiolite is a slice of former oceanic crust from the Piemont-Ligurian ocean that was subducted to eclogite facies conditions during Alpine conversion. This MSc project will focus on the ultramafic rocks of the Antrona ophiolite that crop out to the northeast of Antronapiana. In this locality there are still relic mantle rocks with fresh olivine, whereas orthopyroxene is replaced by talc and tremolite, and spinel by chlorite. The relic mantle rocks are surrounded by serpentine mylonites, where new metamorphic olivine and titanian clinohumite have formed during Alpine subduction.
The main aims of the project are to distinguish the major, minor and trace element composition of mantle olivine from metamorphic olivine, including hydrogen contents and oxygen isotopes. While the serpentinites were dehydrated during burial, the peridotites were hydrated during this subduction event. This interplay of fluid production and consumption serves as a natural analogue of what is expected between the subducting plate and the overlying mantle wedge.
The project will combine petrographic and petrologic studies of ultramafic rocks.
The project will include fieldwork, petrographic characterization of thin sections, electron microprobe, infrared spectroscopy, laser ablation ICP-MS and SIMS analyses.
Advisors: Prof. Jörg Hermann, Prof. Daniela Rubatto
University: BE