ReSiDue addresses how the redistribution of the most common compound in the Earth’s crust – silica – changes the permeability of rocks under volcanically relevant conditions.
Volcanic systems are the ideal case study for the feedbacks between rock-fluid interactions and rock physical property evolution. These systems span almost the entire range of crustal pressure and temperature conditions and are in constant chemical and physical disequilibrium that results in permeability that changes both in space and time.
Volcanic systems host a range of hydrothermal alteration products – acid sulphate, clays, silica – but it remains difficult to predict precisely how much of these products form, on what timescales they form, and where in a chemically complex volcanic system they form.
Consequently, we are currently unable to assess how these types of reactions modify permeability and what possible effects these processes may have on eruption style.
Using a mix of detailed rock physical property, microstructural and geochemical characterization, and fluid-rock interaction experiments, RPGL is quantifying 1) the physical and chemical conditions promoting silica alteration in volcanic edifices, 2) how fluid-flow pathways in rocks change over time as a result of silica alteration, 3) how these changes modify permeable flow, and 4) on what timescales these processes are active.
These four objectives will be achieved through a comprehensive experimental program that will subject analogue, synthetic, and natural rocks to silica-undersaturated and silica-saturated fluids at volcanically relevant conditions.
ReSiDue is funded as part of the SNSF PRIMA grant program and will run through to the end of 2027.