Research

Our research focuses on the physical-chemical processes that act during rock deformation over the whole range of geological scales and on the structures that form during this deformation. We apply the concepts of continuum mechanics and thermodynamics and generate analytical and numerical solutions to quantify geological processes. We compare and calibrate our models with geological, petrological and geophysical observations, laboratory measurements and physics experiments to apply the models to specific natural conditions. We aim to quantify and reconstruct geological processes, to assess physical rock properties, and to quantify the stress and temperature evolution during lithosphere deformation.

“All models are wrong, but some are useful.” (G. Box)

Lithosphere stresses at a subduction zone

Numerous processes such as metamorphic reactions, fluid and melt transfer and earthquakes occur at a subducting zone, but are still incompletely understood. These processes are affected, or even controlled, by the magnitude and distribution of stress. To eventually understand subduction zone processes, we quantify here stresses and deformation mechanisms in and around a subducting lithosphere with numerical simulations. (PhD project of A. Bessat)

Melt migration by reactive porosity waves

How does melt migrate across the lithosphere? What is the interplay between melt transport and the simultaneously ongoing chemical differentiation? We aim to help answering these questions by numerical simulations of melt migration by reactive porosity waves. (PhD project of A. Bessat)

Subduction initiation and orogenic wedge formation

What are the processes controlling subduction initiation? How do orogenic wedges, like the European Alps, form? How are (ultra)high-pressure rocks formed and exhumed? Such fundamental questions related to orogeny are the topic of this research project, for which we apply numerical simulations, flow laws from rock deformation experiments and geological and geophysical observations. (SNSF-PhD project of L. Candioti)

Tectono-metamorphic history of the Monte Rosa nappe, Alps

Different lithologies in the Monte Rosa nappe exhibit significantly different peak pressure magnitudes. Common explanations for these peak pressure variations such as tectonic mixing (mélange), retrogression or sluggish kinetics are not supported by field observations, thin-section analysis and laboratory measurements. The main question is, hence, which peak pressure represents the maximal burial depth of the Monte Rosa nappe and what is the burial and exhumation history of this nappe? We try to decipher the tectono-metamorphic histroy of the Monte Rosa nappe with a combined field, laboratory and modelling study. (SNSF-PhD project of J. Vaughan-Hammon)

Stress in a curved lithospheric shell

Many numerical models that quantify lithospheric stress apply Cartesian coordinates in a rectangular model configuration. However, the Earth’s lithosphere has a double curvature which presumably affects the distribution and magnitude of stress. In this project, we quantify the impact of the double-curvature of the lithosphere on the stress field. We apply HPC-GPU algorithms based on the pseudo-transient finite difference method to quantify stress for spherical geometries. (SNSF-PhD project of E. Macherel)

Heat transfer in the Lepontine dome

What is the reason for the Barrovian metamorphism recorded in the Lepontine dome, Central Alps? How did the emplacement of major tectonic nappes impact the subsequent Barrovian metamorphism? We try to answer these questions with combining field, laboratory and theoretical work (SNSF-PhD project of A. Tagliaferri)

Coupling of reactions, fluid flow and rock deformation

We develop mathematical models and generate numerical simulations to investigate the coupling between heterogeneous rock deformation, fluid flow and metamorphic reactions. We have applied our model to the brucite – periclase reactios, which involves a significant volume change.