FROM THE AVALON TERRANE TO THE SLAVE CRATON, EXAMINING THE GROWTH, STABILIZATION, AND REACTIVATION OF THE NORTH AMERICAN CONTINENT: A TRIBUTE TO DR. MARGARET THOMPSON

The Boston Basin is Meg Thompson's stomping grounds. As an undergraduate at Wellesley College, Meg shared her knowledge of this special part of the world with me as we sought to unravel the protracted history of arc magmatism, volcanism, and sedimentation of the southeast New England Avalon terrane using field observations, geochemistry, and high-precision U-Pb geochronology. Working with Meg not only developed my skills as a geologist but also fostered collaborations with colleagues at MIT. Meg encouraged me to serve as a field assistant to Sam Bowring's former PhD student, Rebecca Flowers. This exposure to field work in the Canadian shield cultivated my desire to understand those processes responsible for the growth, stabilization, and reactivation of continents. Now, as Dr. Flowers' PhD student at the University of Colorado at Boulder, I employ low temperature thermochronometry to continental interiors to elucidate linkages between burial and unroofing patterns, surface uplift and subsidence, and lithosphere-asthenosphere interactions.

My current research has progressed from exploring the tectonic evolution of the eastern margin of North America to the seemingly stable cratonic interior. The Slave craton, despite its thick, chemically depleted lithospheric mantle root, insulation from plate margin processes, and apparent stability, has been repeatedly disrupted by both mafic dikes and kimberlites in the Proterozoic and Phanerozoic. Phanerozoic sedimentary xenoliths contained in kimberlites record the past extent of strata that were subsequently denuded, indicating that the Slave craton underwent a more dynamic history of burial and unroofing than widely recognized. These observations raise the question of whether cratonic deposition and denudation was influenced by Phanerozoic thermal and mechanical perturbations associated with kimberlite emplacement, changing mantle flow regimes, and/or far-field plate boundary processes. Apatite (U-Th)/He thermochronometry data from the western Slave craton, combined with geologic and stratigraphic information, constrain the region's Phanerozoic burial and unroofing history and allow a preliminary assessment of potential relationships among phases of cratonic sedimentation and erosion and deep-seated geodynamic processes.