Disputation: Marthe Grønlie Guren
Doctoral candidate Marthe Grønlie Guren at the Department of Geosciences, Faculty of Mathematics and Natural Sciences, is defending the thesis Imaging and modelling nanoscale dynamics of mineral-mineral and mineral-fluid interfaces during mechano-chemical transformations for the degree of Philosophiae Doctor.
Marthe Grønlie Guren. Photo: Private
The PhD defence and trial lecture will be held in Auditorium 1, The Geology Building. In some cases, it will be possible to attend the trial lecture and dissertation digitally, in that case a link to Zoom will be posted.
Thursday 17 March, 13:15-14:00, Aud 1, The Geology Building / Zoom:
The role of evaporite deposits in tectonics
Conferral summary (in Norwegian)
Reaksjoner mellom bergarter og væsker er viktig for prosesser som skjer i jordskorpen, fra forvitring på overflaten til metamorfe omdannelser i nedre skorpe. For å forstå disse prosessene er man avhenging av å forstå hva som skjer på nanoskala langs mineraloverflatene. Denne avhandlingen dekker i hovedsak to temaer, oppløsning og oppsprekking av mineraler på nanoskala.
Main research findings
Popular scientific article about Guren’s dissertation:
Imaging and modelling nanoscale dynamics of mineral-mineral and mineral-fluid interfaces during mechano-chemical transformations
Nanoscale interactions at mineral-fluid interfaces are important for processes occurring at the Earth's crust. Mineral dissolution occurs when a mineral is in contact with a fluid over time and can be observed by a change in mass. For dissolution to proceed, a fluid must be in contact with the crystal surface. If the mineral is not in contact with the fluid, the rock must provide a pathway to the mineral by a fracture or a fracture network.
The projects in this thesis have focused on dissolution kinetics and fracturing, and the results indicates that the access of water to a reacting surface might be limited by the compressive stress. When the stress increases, this might shut off the water supply which will limit mineral dissolution and hydration of minerals. However, when the compressive stress is smaller, there will be a constant water flow to the reacting surface, and dissolution and hydration reactions might progress. If the hydration reaction occurs with a volume increase, the surrounding rock might fracture. These fractures can propagate through the crystal as straight, oscillating or branching cracks, which cause damage in the surrounding material.
Photo and other information:
Press photo: Marthe Grønlie Guren, portrett; 420px Photo: Private