Understanding how tectonic inheritance controls the evolution of mountain belts

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The proposed research will aim to determine the control that tectonic inheritance, defined by pre-existing structures (e.g. faults) and heterogeneity of the Earth's crust, has on mountain building processes and fault reactivation (movement) at the frontal parts of mountain belts (orogens). During mountain building, pre-existing basement structures are critical, relatively weak zones prone to reactivation and provide necessary pathways for the migration of magma, heat, and basement-sourced metals. The research program will focus on the Northern Appalachians (in Canada and the US) where tectonic inheritance has been invoked as having major orogen-scale impacts on mountain building processes; however, evidence showing pre-orogenic fault geometry is speculative and significant reactivation of pre-orogenic faults is largely unrecognized. My recent work in the NL Appalachians demonstrates that tectonic inheritance is significant and that deep-basement rooted faults have been reactivated multiple times during Appalachian Mountain building. I hypothesize that analogous basement structures, generated prior to mountain building and reactivated multiple times, also occur in both Quebec and New England, the southern extension of the Northern Appalachian orogen. The proposed research will test this hypothesis through a multidisciplinary research program requiring detailed geological mapping, stratigraphic and structural analyses, geochronology, and geophysical interpretation. If tectonic inheritance is shown along the Northern Appalachians, traditional models that explain how the Appalachian Mountains were formed will be significantly revised to show that basement-faults are associated with a significant amount of transport and that these faults have a complex history of motion. From an economic perspective, results will allow for the identification of critical geologic structures typically formed during basement fault reactivation, which are often associated with petroleum traps or potential injection sites. Reactivation of basement faults is also directly associated with fluid flow episodes, which are critical to transport metals and heat from deep in the Earth's crust upwards to shallower depths to form sedimentary-hosted mineral systems and provide geothermal energy resources. From a geohazard perspective, these results will allow us to better understand the link between inherited structure and seismic events, which occur in the foreland of orogen's worldwide.