Grant: Discovery Grants Program - Individual

Broad tectonic stresses over the Earth's outer solid shell cause localized deformation along fault zones. Deformation leads to the displacement of rock, and this large-scale movement of heat and fluids during mountain building exerts a major control on burial, heating and potential mineral transformation, and plays a key role in the distribution of economic ore deposits and hydrocarbon reservoirs. Understanding the tempo of these tectonic events across deep time is fundamental for making predictions about the solid Earth on shorter timescales. However, rock structures, such as faults, joints, and cleavage, that formed under low-temperature conditions (100-450°C) are difficult to date, despite the usefulness of this information for resolving the shallow crustal history of the Earth. This low-temperature crustal domain lies within the extremes of surficial processes governing the interactions between deformation-erosion and climate-topography feedback mechanisms, and the now exposed roots of mountain belts that provide insights into magma generation and midcrustal flow. As rocks pass through the these low-temperature ranges, they experience a transition from brittle to plastic deformation mechanisms, undergo significant dehydration and reach the peak of mechanical strength. As such, this transition zone controls the location, localization and displacement of major crustal fault zones and is a potential clutch between surface topography and deeper portions of the Earth. Developing new, and improving existing, dating technologies that are capable of capturing the timing of deformation is the long-term goal of my research. The innovative geochronometers that specifically cover this temperature range which my research group is currently focusing on include U-bearing and K-bearing minerals, including common calcite and iron oxides. Notably, we are partly focusing on deformed carbonate-dominated regions since they present significant challenges for geochronology as they lack the traditional minerals required for such analyses. Together with Discovery Grant support, my work embarks upon a new phase of Earth science research involving students and international collaborators, developing innovative low-temperature geochronology techniques, and rewarding my students with having access to, and training on, world-class instruments. Although concentrating on fundamental issues such as the life cycle of mountain belts, this research has impacts through the Earth Sciences, from submicron-scale isotope mobility to mega-scale tectonism. More directly, this research has specific applications to natural resource exploration, including determining the timing and duration of ore-bearing fluid flow and the burial history of petroleum reservoirs.