Mérédith Morin

Doctorante / PhD Student

Subject:

The magmatic differentiation mechanisms of the continental crust: The permian magmatic systems of Western Europe.

 

Beginning and end of thesis:

September 2020 - September 2023

Supervisors:

  • Marc ULRICH, EOST-ITES, University of Strasbourg - FRANCE
  • Benoît PETRI, EOST-ITES, University of Strasbourg - FRANCE

In collaboration with:

Othmar MUNTENER, University of Lausanne - SWITZERLAND

Subject description :

The continental crust is composed of three parts : Upper crust, middle crust and lower crust. We know that there is a continental crust differenciation through physical and chemical properties. In fact, the more the seismic waves pass through the crust, the more their velocities increase. In addition, the SiO2 and K2O content decreases as one moves from the upper crust to the lower crust. 

The aim of this thesis is to understand what are the magmatic processes leading to differentiation within the continental crust in the context of the stable continental crust formation. We will therefore try to answer the following questions: How do the magmas transit through the crust? What is the place of differentiation? Is it governed by fractional crystallization? What is the impact of crustal assimilation and magma hybridization on this differentiation? 

A multi-method approach will be used to answer these chemical and mechanical issues. These approaches consist of fields, petrography and quantitative microstructural analysis for the mechanical part of crustal differentiation as well as elemental geochemistry, isotopic and thermodynamic modelling for chemical issues. 

 

Fields:

Southern Alps, Ivrea-Verbano Zone - ITALY

Eastern Alps, Sondalo Complex - ITALY

 

Keywords: Alps, metamorphism, magmatism, permian, miscroscture, differentiation, assimilation