Publications associées à Roche ultramafique

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

The influence of water-saturation on the strength of volcanic rocks and the stability of lava domes

Marie Estelle Solange Violay, Michael Heap

The rocks forming a volcanic edifice or dome are typically saturated or partially-saturated with water. However, most experiments aimed at better understanding the mechanical behaviour of volcanic rocks have been performed on dry samples, and therefore mos ...

2023

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

Rock strength properties of granitic rocks in Yosemite Valley, Yosemite National Park, California

Federica Sandrone, Michel Jaboyedoff

Yosemite National Park, located in the central part of California’s Sierra Nevada mountains, is a glacially carved landscape filled with iconic rock formations such as Cathedral Peak, El Capitan, and Half Dome. Igneous rocks, consisting primarily of variat ...

U.S. Geological Survey2020

Taking the pulse of volcanic eruptions using plagioclase glomerocrysts

Anders Meibom, Stéphane Laurent Escrig, Anders McCarthy, Pierre Vonlanthen

Crystallization timescales in subvolcanic systems and the consequences of interaction between ascending magmas and gases remain largely unconstrained, as do links between these processes and monitoring signals at restless volcanoes. We apply diffusion chro ...

ELSEVIER2020

Seismic and Microseismic Signatures of Fluids in Rocks: Bridging the Scale Gap

Lucas Xan Pimienta, Christian David

The aim of this collection is to record a snapshot of our current state of understanding of the impact of fluids on the evolution and monitorability of subsurface rock formations during anthropogenic fluid injection/withdrawal operations, accounting for sc ...

AMER GEOPHYSICAL UNION2019

Seismic Dispersion and Attenuation in Fluid-Saturated Carbonate Rocks: Effect of Microstructure and Pressure

Lucas Xan Pimienta

The frequency dependence of seismic properties of fully saturated rocks can be related to wave-induced fluid flows at different scales. The elastic dispersion and attenuation of four fluid-saturated carbonate rocks, with different microstructures, have bee ...

2019

Anomalous Vp/Vs ratios at seismic frequencies might evidence highly damaged rocks in subduction zones

Marie Estelle Solange Violay, Lucas Xan Pimienta

Unusually high compressional (P) to shear (S) wave velocity ratios (V-p/V-s) were measured at different subduction zones and interpreted as fluid-pressurized regions. Because no laboratory data reported such high values in isotropic rocks, mineralogical or ...

2018

Supercritical CO2 injection and residence time in fluid-saturated rocks: Evidence for CO2 and mineral dissolution and effects on rock integrity

Lucas Xan Pimienta, Ke Liu

CO2 injection and storage in geological reservoirs is an attractive prospect for mitigating the anthropogenic production of greenhouse gases and global warming. The technology could lead to mineral precipitation and therefore stable storage over geological ...

Elsevier Sci Ltd2017

Vertical changes of the Co and Mn speciation along a lateritic regolith developed on peridotites (New Caledonia)

Gabrielle Dublet, Vincent Noel

Because they can host significant amounts of Co, the Mn-oxides are commonly considered as the major Co-bearing mineral species in lateritic environments. However, little is known about the process leading to the formation and/or the weathering of these Co- ...

Pergamon-Elsevier Science Ltd2017

Distributed snow and rock temperature modelling in steep rock walls using Alpine3D

Michael Lehning, Nander Wever, Mathias Thierry Pierre Bavay

In this study we modelled the influence of the spatially and temporally heterogeneous snow cover on the surface energy balance and thus on rock temperatures in two rugged, steep rock walls on the Gemsstock ridge in the central Swiss Alps. The heterogeneous ...

Copernicus GmbH2017

Phase transition processes of olivine in the shocked Martian meteorite Tissint: Clues to origin of ringwoodite-, bridgmanite- and magnesiowilstite-bearing assemblages

Philippe Gillet

Tissint is a heavily shocked olivine-phyric shergottite. We investigated and documented several phase transformations and dissociation phenomena of olivine adjacent to and in many shock-induced melt-pockets of Tissint. Olivine grains entrained in the melt- ...

Elsevier2016

Quantitative analysis of deformation in hollow cylinder tests on anisotropic clay formations

Vincent Labiouse, Gioacchino Viggiani, Shuang You

A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay. The aim of this testing program is to better understand the anisotropic deformation during the excavation. The testing conditions are similar ...

2015

Unique large diamonds in a ureilite from Almahata Sitta 2008 TC3 asteroid

Philippe Gillet

The Almahata Sitta MS-170 ureilite (a piece of a breccia originating from the asteroid, 2008 TC3) consists mainly of olivine, with many diamond and graphite grains existing between the olivine grains. The occurrences of the diamonds are unique; i.e., (i) s ...

Pergamon-Elsevier Science Ltd2015

Crustal differentiation in the early solar system: Clues from the unique achondrite Northwest Africa 7325 (NWA 7325)

Philippe Gillet

The unique achondrite NWA 7325 is an unusual olivine gabbro composed chiefly of calcic plagioclase (An(85-93)), diopsidic pyroxene (En(50.1-54.0) Wo(44.8-49.3) Fs(0.6-1.3)), and forsteritic olivine (Fo(97)). It is Al and Mg-rich and Fe and Na-poor and disp ...

Pergamon-Elsevier Science Ltd2015

A Microstructure-Based Model to Characterize Micromechanical Parameters Controlling Compressive and Tensile Failure in Crystallized Rock

Jian Zhao, Tohid Kazerani

A discrete element model is proposed to examine rock strength and failure. The model is implemented by UDEC which is developed for this purpose. The material is represented as a collection of irregular-sized deformable particles interacting at their cohesi ...

Springer Verlag2014

Effect of Loading Rate on Fracture Behaviour of Rock Materials

Yang Zou, Qianbing Zhang

In this paper, experiments are carried out to study the quasi-static and dynamic fracture behaviour of sedimentary, igneous and metamorphic rocks. The notched semi-circular bending method has been employed to determine fracture parameters over a wide range ...

2014

Quasi-static and dynamic fracture behaviour of rock materials: phenomena and mechanisms

Jian Zhao, Qianbing Zhang

An experimental investigation is conducted to study the quasi-static and dynamic fracture behaviour of sedimentary, igneous and metamorphic rocks. The notched semi-circular bending method has been employed to determine fracture parameters over a wide range ...

Springer Verlag2014

A newly developed soil abrasion testing method for tunnelling using shield machines

Jian Zhao

The importance of the effect of ground abrasivity on the performance of a tunnel boring machine (TBM) is important for many tunnelling projects. In recent years, many abrasivity devices have been developed to measure soil abrasivity for specific conditions ...

Geological Society2013

An experimental model approach of biologically-assisted silicate dissolution with olivine and Escherichia coli - Impact on chemical weathering of mafic rocks and atmospheric CO2 drawdown

Philippe Gillet, Bruno Garcia

Chemical weathering of Mg, Ca-silicates and alumino-silicates contributes significantly to the drawdown of atmospheric CO2 over long time scales. The present work focuses on how this mode of weathering may change in the presence of free-living bacteria in ...

Pergamon-Elsevier Science Ltd2013