Grant: Discovery Grants Program - Individual

The assembly and destruction of supercontinents throughout Earth's history have created continents and mountain belts, and shaped our landscapes. My research program is built around three different components or areas of the Appalachian orogen, each spanning a different period of time, each related to a different phase in the assembly of Pangaea, the most recent supercontinent. The first component is the Proterozoic inliers of Laurentian (Grenvillian) crust found that occur in Newfoundland and Cape Breton Island and represent the oldest rocks exposed in the Appalachians. In the Proterozoic inliers my work focuses mainly on the original affinity of the inliers, and the metamorphic and igneous histories that they preserve.The second component is Cape Breton Island which is a highly compressed cross section through the Laurentian, Ganderian, and Avalonian components of the orogen and record all the major phases of collision that constructed the orogen. Significant gaps remain in our data and interpretations regarding the structural evolution and the nature and history of the metamorphic rocks that make up large parts of the Ganderian terranes. The third component is the Meguma terrane which was the last terrane to be juxtaposed with Avalonia during the final phases of supercontinent assembly. The Meguma terrane was accreted in a primarily transpressional setting but contains primarily compressional structures voluminous S-type granite throughout the terrane, both more likely associated with compression. The scientific approach in my work follows a multi-disciplinary approach based on extensive field work augmented by laboratory work because analytical work is only as good as the understanding of field relationships and basic geology of an area. While my work is broadly focused on metamorphic rocks and related tectonic problems, the methods I use are heavily dependent on structural geology and geochronology as analytical tools. The scientific questions I address in my research vary widely and therefore need multiple analytical approaches. My work will improve the correlations between Meguma and other exotic terranes in the Appalachian orogeny, on the North American margin and in Europe. By extension, the answers to these questions are also applicable to the study of other supercontinent cycles in Earth's history. The Appalachian orogeny and specifically the Meguma terrane provides an excellent window into the assembly of Pangea which is the most recent supercontinent, and therefore the best-studied and most easily understood one. Better constraints on the processes and systems operating in recent periods of continental assembly are critical in understanding the assembly and evolution of older supercontinents which formed earlier in Earth's history and are now poorly exposed and overprinted by more recent events.