Title of the talk: Nanoscale experiments of intergranular dissolution-precipitation to understand deformation mechanisms in the upper crust.
In the upper crust, rock deformation commonly occurs in the presence of aqueous fluids, which are known to alter the material's response to stress. These fluids facilitate dissolution and precipitation, driving changes in the mineral composition and texture. The interaction between dissolution-precipitation and deformation in the upper crust has been studied in various natural geological cases, through experimentation, and modeling. Recently, there has been increased emphasis on understanding the role of fluids in deformation at the nanoscale.
My research focuses on understanding quartz dissolution and precipitation at the grain boundary scale under hydrostatic pressures and temperature conditions representative of the upper crust. I will present preliminary findings from experiments on nano-milled quartz crystals, which simulate natural grain boundary geometries, in contact with different aqueous solutions in a closed system. Additionally, I will provide a sneak peek into the experiments conducted at Njord during my visit. These experiments aim to evaluate the effects of differential stress on dissolution and precipitation with varying crystallographic orientations, grain boundary geometries, and fluid compositions. Overall, these studies seek to improve our understanding of dissolution rates in relation to pressure solution, a significant deformation mechanism in sedimentary and fault rocks.
Andrea is a PhD candidate in the Structural Geology and Petrology groups at Utrecht University's Earth Science department. Before joining UU, she earned her BSc (2017) and MSc (2019) in Earth Sciences from Universidad Nacional Autónoma de México (UNAM). Her research focuses on using chemical tracers to investigate dissolution and precipitation reactions. Andrea's work ranges from tracing the exchange of oxygen isotopes in dissolved carbonate and silicate systems to studying the initial stages of mineralization, including potential trace element and isotope fractionation. She is also conducting experiments to constrain the effects of fluid composition and grain boundary geometries on pressure solution in quartz.
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