Structural and magmatic evolution of rifts and passive margins: implications for continental breakup and natural resources in Canada

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The solid outermost layer of the Earth, known as the lithosphere, is classified as either continental or oceanic depending on its origin and composition. Continental lithosphere can be stretched and eventually torn apart opening a new ocean creating a transition from continental to oceanic lithosphere called a passive margin. Passive margins related to the opening of the Atlantic Ocean characterize Eastern Canada from the Arctic to Nova Scotia, and older examples are also preserved onshore. Using a highly original and innovative onshore-offshore approach integrating both geological and geophysical methods, my research examines how extensional tectonic processes shaped the geology of Canada, and their importance in the formation and preservation of natural resources that are relevant to Canadian environmental and economic needs. Passive margins are classified as magma-rich or magma-poor, based on the volume of rift- and breakup-related magmatism (molten rock). Canada is the ideal research location as both types occur. Magma-rich margins are postulated to relate to elevated temperatures (e.g. mantle plumes) and `active' rifting, whereas magma-poor margins are suggested to be driven by `passive' far-field extension. However, ambiguity of evidence for mantle plumes and magmatism on magma-poor margins suggests the end-member classification is an oversimplification as it fails to account for structural inheritance (the role of older structures) or explain phenomena such as rift obliquity (non-orthogonal extension). As such, whether continental rifting and breakup is driven by active or passive processes, the role of structural inheritance, rift obliquity, and the relationship of these mechanisms to rift-related magmatism are unresolved and will be the focus of this groundbreaking research program. The long-term goal of this research program is to advance the understanding of the drivers and controls of continental rifting and breakup by answering the presently unresolved question: To what extent is passive margin structure and evolution controlled by magmatism versus structural inheritance? The innovative, integrated, and comprehensive approach will involve geological and geophysical mapping of rift-related deformation and magmatism in Eastern Canada followed by modelling and plate reconstructions. Most previous work studies either only the onshore or the offshore region. Here however, both onshore and offshore regions will be studied to provide an innovative insight and therefore lead to impactful advancements.The impact of this will be realised by advancements in the offshore exploration industry who will benefit from enhanced sub surface knowledge which will translate into more successful and environmentally responsible exploration. Wider Canadian society will also reap economic benefits as a result of these industrial advances, and the academic community will benefit from increases in the fundamental understanding of global tectonic processes.