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Concept

Roche métamorphique

Publications associées (31)

Diffusion timescale conundrum in contact metamorphism: Oxygen isotope and trace element profiles in dolomite

Anders Meibom, Stéphane Laurent Escrig, Lukas Baumgartner

Successful application of diffusion chronometry is based on detailed knowledge of diffusion parameters obtained from laboratory experiments, which also need to be upscaled to be applied to natural samples. While generally applicable, several examples of di ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Elongated hydraulic fracture emerging from layers of alternating fracture toughness

Brice Tanguy Alphonse Lecampion, Carlo Peruzzo

Whether used to enhance the hydrocarbon production from low permeability rocks or to measure the minimum in-situ principal stress in rock formations, height growth of a hydraulic fracture above the formation of interest is a key metric for the design of su ...

2023

Fluid flow through microcracked and fractured granitic reservoirs

Marie Estelle Solange Violay, Michael Heap, Lucille Jocelyne Nadine Carbillet

The permeability of crustal rocks and rock-masses dictates the efficiency of hydrothermal circulation and therefore the productivity of geothermal resources. In this study, we find by monitoring P-wave velocity that thermal microcracking in Lanhélin granit ...

2023

Three-dimensional hydraulic fracture propagation in homogeneous and heterogeneous media

Carlo Peruzzo

Hydraulic fractures are tensile fractures that occur in solid materials due to the natural intrusion or anthropogenic injection of a viscous fluid into a fracture channel. The deliberate creation of hydraulic fractures is part of an industrial technology h ...

EPFL2023

Oxygen diffusion in garnet: Experimental calibration and implications for timescales of metamorphic processes and retention of primary O isotopic signatures

Anders Meibom, Stéphane Laurent Escrig

Knowledge of oxygen diffusion in garnet is crucial for a correct interpretation of oxygen isotope signatures in natural samples. A series of experiments was undertaken to determine the diffusivity of oxygen in garnet, which remains poorly constrained. The ...

MINERALOGICAL SOC AMER2022

Nanotwinning-assisted recrystallization

Roland Logé

Dynamic recrystallization helps to refine grain structures in metals and tune their properties. Confining recrystallization within prior nanoscale twinning provides a path for reaching exceptional grain refinement. ...

NATURE PORTFOLIO2022

A Ribbon Model for Nematic Polymer Networks

Harmeet Singh

We present a theory of deformation of ribbons made of nematic polymer networks (NPNs). These materials exhibit properties of rubber and nematic liquid crystals, and can be activated by external stimuli of heat and light. A two-dimensional energy for a shee ...

SPRINGER2022

Experimental plastic reactivation of pseudotachylyte‐filled shear zones

Marie Estelle Solange Violay, François Xavier Thibault Passelègue

Pseudotachylytes are fine‐grained fault rocks that solidify from melt that is produced in fault zones during earthquakes. Exposed sections of natural fault zones reveal evidence of post‐seismic plastic deformation (i.e. reactivation) of pseudotachylyte, wh ...

2021

Inorganic and Metal-Organic Heterogeneous Catalysts for Hydrogen Energy Applications

Fatma Pelin Uran

The main focus of this thesis is the exploration of inorganic and metal-organic heterogeneous catalysts for hydrogen (H2) energy applications. In particular, we investigated metal nanoparticles (NPs) and metal-organic frameworks (MOFs) for their employment ...

EPFL2021

A new data set of granitic rock strength values from Yosemite Valley, California: applications to rock fall assessment

To explore connections between rock strength and rock falls, we undertook a comprehensive rock mechanics testing program for six granitic rock types in Yosemite Valley (California, USA) where rock falls are a common geomorphic and sometimes hazardous proce ...

2020

Evidence of extensive lunar crust formation in impact melt sheets 4,330 Myr ago

Cyril Cayron

Accurately constraining the formation and evolution of the lunar magnesian suite is key to understanding the earliest periods of magmatic crustal building that followed accretion and primordial differentiation of the Moon. However, the origin and evolution ...

2020

Dissolution-reprecipitation reaction of dolomite: investigation of self- and tracer-diffusion using SIMS mini-spot and NanoSIMS profiles

Anders Meibom, Stéphane Laurent Escrig, Lukas Baumgartner

Recrystallization of minerals due to fluid infiltration modifies their original chemical and isotopic signature. Such processes are sought after as they give access to timescales of geologic processes, which are commonly quantified using diffusion chronome ...

2019

Chemical shrinkage of ye'elimite with and without gypsum addition

Karen Scrivener, Mohsen Ben Haha, Frank Bullerjahn

Ye'elimite (Ca4Al6O12SO4 or C(4)A(3)S) is the main hydraulic mineral present in calcium sulphoaluminate cement (CSA). Its reaction is responsible for the (early) hydration and associated cement properties such as the chemical shrinkage. This paper discusse ...

ELSEVIER SCI LTD2019

Dynamic recrystallization study of a Fe-Mn-Si based shape memory alloy in constant and variable thermomechanical conditions

Roland Logé

The dynamic recrystallization of a Fe-Mn-Si based shape memory is studied for the first time, under constant and variable thermo-mechanical conditions. The effect of strain rate and deformation temperature on the microstructural evolution is investigated, ...

ELSEVIER SCIENCE INC2019

Pore space properties in carbonate fault rocks of peninsular Italy

Marie Estelle Solange Violay

The fault cores of extensional faults in Mesozoic limestones and dolostones are examined by mean of combined microstructural, ultrasonic and petrophysical analyses. Grain-supported fault rocks commonly localize in the outer fault cores, whereas matrix-supp ...

2019

Variations in elastic and electrical properties of crustal rocks with varying degree of microfracturation

Marie Estelle Solange Violay, Lucas Xan Pimienta, Luis Felipe Orellana Espinoza

This work aims at investigating the effect of varying degrees of microfracturing on the joint elastic and electrical transport properties of rocks. Different crustal rocks were subjected to Thermal Treatment, expected to induce microfracturing, up to diffe ...

2019

Plagioclase Glomerocrysts: taking the pulse of volcanic eruptions

Anders Meibom, Stéphane Laurent Escrig

Volcanic eruptions result from complex interplay of magmatic processes including the ascent and storage of magma in the crust, volatile exsolution and crystallization. The dynamics of crystallization in shallow subvolcanic systems and the consequences of i ...

2019

Basic creep and autogenous shrinkage of Limestone Calcined Clay Cement (LC3)

Julien Ston

The use of supplementary cementitious materials (SCM) to lower the clinker factor of cements is now commonplace, for it benefits performance, economics and ecology. This thesis focuses on ternary blends of limestone and calcined kaolinitic clays, two very ...

EPFL2019

Hydro-mechanical response of Opalinus Clay shale: dependency on composition and burial depth

Eleonora Crisci

Shales are sedimentary formation currently studied for their involvement in many geo-energy related applications, such as radioactive waste disposal, CO2 sequestration, oil and gas extraction. In Switzerland the Opalinus Clay shale has been selected has ho ...

EPFL2019

Frictional and transport properties of faults zones in the Opalinus Clay formation

Luis Felipe Orellana Espinoza

Deep geological repositories in clay formations are a promising option to ensure the long-term isolation of nuclear waste from the population and the environment. In Switzerland, the Opalinus Clay (OPA) formation is a shale whose favorable barrier properti ...

EPFL2018