The bridge between a convecting mantle and tectonic crust: Geodynamics of the mantle lithosphere

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My proposed research will explore the dynamics of the mantle lithosphere as the important bridge zone between the tectonically energetic crust and fluid convecting mantle below. The mantle lithosphere is the sub-crustal portion of the Earth's lithosphere and makes up the largest component member of the continental tectonic plates. Compared to the overlying crust and fluid mantle below, its evolution is little studied and poorly understood. My research program will make tangible advancements in our understanding of this subsurface horizon of the Earth by answering key outstanding questions in three targeted environments where continental mantle lithosphere is/was tectonically active: (1) Do pre-existing "scars" control the tectonic response of the lithosphere?; (2) How and why does mantle lithosphere get completely/partially removed in some regions and what are the consequences at the surface?; (3) What happens when the deep mantle lithosphere collides to form mountains at a tectonic plate boundary zone? The research will explore these questions in tectonically strategic field areas including the plateaus of Anatolia, the Eurekan Orogeny in Canada's high arctic, the Zagros fold-thrust belt in Iran, and the alpine plate boundary zone of the South Island of New Zealand. The research will be carried out by a diverse team made up of undergraduate and graduate students, and a post-doctoral fellow and research associate. We use computational geodynamics for our investigations and the research group is developing advanced new 4-dimensional tools where we consider evolution of the models through time and in three spatial dimensions. In addition, we will be using physical scaled analogue modelling that give us a unique and detailed view of the tectonics from a laboratory benchtop (a significant challenge in studying planetary-scale geodynamics!). As a new and novel application in geosciences we will experiment with approaches in artificial intelligence (AI)-namely, machine learning and neural network techniques to identify governing Earth parameters and classify the Earth's various observed modes of tectonic behaviour. This application of AI to the geosciences is not an established practice, but it is genuine discovery-based research with potential far-reaching impact. The mantle lithosphere is the bridge between the mantle thermal engine and tectonically mobile crust and this research will help reveal what drives global plate tectonics-one of the primary enigmas of our energetic planet. Also, as the site for the genesis of diamond bearing volcanic kimberlite pipes, the study of the evolution of the continental mantle lithosphere has direct implications for understanding the development of important resources within Canada's mineral industry. Across a broader frontier, the research will help decipher the geologic evolution of terrestrial bodies such as Venus, Mars, Io, and Europa that display much different surface tectonic activity compared to Earth.