A5000472346- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- earthquake and tectonic studies
- Geomagnetism and Paleomagnetism Studies
- Hydrocarbon exploration and reservoir analysis
- Seismic Imaging and Inversion Techniques
- Theoretical and Computational Physics
- Geophysics and Gravity Measurements
- Geological Studies and Exploration
- Metal Extraction and Bioleaching
- Advanced Materials Characterization Techniques
- Geological and Geophysical Studies
- Geophysics and Sensor Technology
- Geotechnical and Geomechanical Engineering
- Seismology and Earthquake Studies
- Iron and Steelmaking Processes
- CO2 Sequestration and Geologic Interactions
- Crystal Structures and Properties
Géosciences Montpellier
2014-2024
Université de Montpellier
2004-2022
Centre National de la Recherche Scientifique
1995-2022
Laboratoire de Physique des Interfaces et des Couches Minces
2014
University of California, Berkeley
1997
Centre National d'Études Spatiales
1994-1997
The Earth's non-hydrostatic gravity field, or geoid, provides a first-order constraint on mantle density structure and dynamics. Geodynamic models for the geoid have proliferated since advent of seismic mapping heterogeneity (tomography) because offers perhaps best-measured independent heterogeneity. However, dynamic involve number questionable physical assumptions uncertainties whose effects need to be evaluated before geodynamic inferences based upon can considered sound. Troubling issues...
We use forward models based on recent high‐pressure experimental data mantle minerals to predict the seismic anisotropy produced by plastic strain of orthorhombic wadsleyite, dominant mineral in upper transition zone. These a weak for polycrystal pyrolitic composition (60% 40% garnet) at zone conditions: ∼2% P and ∼1% S waves shear 1. Both wave patterns show an symmetry. propagate faster low angle direction slower high plane. is characterized propagation polarized direction. Horizontal...
Hydrogen distribution between nominally anhydrous minerals (NAMs) of a garnet-lherzolite under subsolidus conditions has been investigated. Separated NAMs from garnet-peridotite Patagonia (Chile) are annealed together (olivine, orthopyroxene, clinopyroxene, and garnet) using piston-cylinder at 3 GPa 1100 °C talc-pyrex cell assembly for 10, 25, 100 h. The provides enough hydrogen in the system to re-equilibrate concentrations high pressure. three coexisting (NAMs, i.e., olivine,...
We compute Green functions relating mantle mass heterogeneities to geoid undulations using both incompressible and radially compressible rheologies. Our results differ from those previously published by Forte & Peltier (1991) Thoraval, Machetel Cazenave (1994). This is due two factors. Instead of taking gravity as constant throughout the mantle, we it self-consistently with radial density profile. Secondly, show that in mathematical formulation case, stresses are not continuous through a...
In the present work, we use a numerical modelling approach based on 2.5-dimensional dislocation dynamics simulations to investigate transition between power and exponential laws in olivine for temperatures ranging 800 K 1700 stresses 100 500 MPa. We model deformation of an crystal by interplay glide climb dislocations. Plastic strain is produced glide, amount gliding dislocations being controlled acting as recovery mechanism. Within this framework, without need introducing any other...
Two‐dimensional numerical simulations of mantle convection with temperature and pressure dependent viscosity are used to study plume–lithosphere interaction beneath a fast moving plate. Plumes behavior and, hence, their erosional melting potential, depend on the Rayleigh number plume buoyancy flux. Analysis balance between large‐scale plume‐induced flow ability melt allows put bounds upper (10 20 , 10 21 Pas), plumes diameter (<200 km) anomaly (200–400°C). Within this range parameters,...
The influence of mantle compressibility and warping the ocean surface on dynamical models geoid has been investigated. Topography kernels show that modifies mantle-flow pattern hence geoid, whereas deflection oceanic amplifies signal without affecting global flow. combined these two effects is significant depends viscosity profile in mantle. Comparisons with incompressible geoids including improves fit to observed geoid. Thus must not be neglected computations
Abstract Water enters Earth's mantle via subduction of hydrated oceanic slab and largely returns to the ocean‐atmosphere system through arc volcanism. However, extent which H 2 O is transferred into deep poorly constrained. Here, we address this question by combining mineral chemistry bulk‐rock geochemistry data for aillikites related plume generated Permian Tarim large igneous province (NW China). The water contents olivine phenocrysts are 75–168 ppm positively correlated with Ti contents....
Initiation of new plate boundary can be related to a spatio-temporal evolution an intraplate vast diffuse deformation towards narrow highly deforming boundary. It also occur by reactivation inherited weak zone. In all cases, breaking requires weakening the lithospheric cold mantle, whose rheological parameterisation often features &#171;&#160;yield strength&#160;&#187; formulation that is not clearly actual mechanisms. On other hand, bulk effective viscosity for mantle rocks,...
Abstract In continuum mechanics, viscous materials are those that lack rigidity and elastic response under shear stress. We argue using the term to refer aseismic lithosphere is thus a misnomer because it denies propagation of S waves through in total contradiction decades seismic surveys. Similarly, yield stress, which another feature expected most situations within but more difficult assess. Aiming reconcile definitions rheological terms between material Earth mineral sciences, we propose...