Stephanie Vialle
Senior Lecturer
Weathering and diagenetic alterations of minerals in the subsurface are part of the geological cycling of elements, transforming primary elements into secondary minerals, more stable under their current physical and chemical environment. These processes lead to complex rock composition and microstrucuture. Furthermore, anthropogenic proceses such as underground geological carbon storage, CO2 Enhanced Oil Recovery or geothermal energy recovery, may trigger diagenetic alterations too.
I am interested in understanding how these weathering and digenetic alterations affect rock properties and geophysical observable monitored at the surface.
Weathering of buried archeological ceramic glazes
At the University Paris 6 and the Centre de Recherche des Musees du Louvre
During my master, I worked with archeologists and geochemists on buried altered ceramic glazes. With the help of SEM imaging and SEM-EDX analyses, I proposed a physical-chemical model that explains the formation of bands rich in lead carbonate within the glaze of weathered samples, giving them an iridescent aspect.
Vialle, DEA report, 2002
CO2-induced opening of sealed fractures of a granitic rock.
With the FAST and IDES groups, Uni Paris 11, and the seismology and rock physics groups, IPG Paris
The laboratory quarry of Mayet-de-Montagne, Central France is at an original scale between the lab and the field, and consists of a 1 m3 fractured granite block, isolated from the rock formation. The fractured network had been previously characterized with seismic and electric methods (Andre, 2004), showing a set of open fractures, orientiend N-S, and a second set of calcite-sealed fractures, oriented E-W. In 2005, CO2-rich brine was injected at the center of the block, partially reopening some of the sealed fractures, as shown by chemical analysis of samples fluids and local hydraulic conductivity measurements.
Assessment of diagenesis alteration of multi-barrier systems for CO2 storage - Collie South West CO2 Hub, Western Australia
With the Dept. of Exploration Geophysics, Curtin Uni and CSIRO, Perth, Australia
soon ...