The Appalachians are a composite mountain belt consisting of various microcontinents, oceanic and continental volcanic arcs and (meta)sedimentary domains that collided during the Appalachian mountain building events. Geological investigations in the Appalachian commonly emphasize the amalgamation history of the various terranes. This proposal focuses on the syn- to post-collisional exhumation history of the deeper domains, as well as late-stage collapse of the mountain belt, to gain fundamental insights into late- to post-mountain formation processes in the northern Appalachians and beyond. Research is carried out in the southeastern New England section of the Appalachians through a strongly integrated research and educational plan.
The southeastern New England Appalachians generally consist of three terranes. From west to east they are the Merrimack, Nashoba and Avalon terranes. The Nashoba terrane is bounded by moderately NW-dipping faults. Preliminary field data suggest that deeper domains within the Nashoba terrane may have extruded towards the east, based on fold geometries, metamorphic characteristics and the apparent relationship between approximately 395 million year melts in the Nashoba terrane and approximately 395 million year intrusions in the structurally overlying Merrimack terrane. Furthermore, preliminary field observations indicate that most inter- and intra-terrane shear zones show evidence for late low-grade normal movement, presumably related to late-stage mountain collapse. The purpose of this research is to investigate both the high-temperature and low-temperature exhumation and collapse mechanisms through a combination of field mapping, detailed structural analysis and cutting-edge radiometric dating techniques.
Integration of research and field work into the undergraduate student experience is central to this project. Students from various geoscience departments in the Boston area are encouraged to participate and collaborate through a Geological Field Research course, giving them an excellent opportunity to discuss research with their peers and creating a stronger community. Subsequent thesis research by undergraduate and MS students involves analytical work at Boston College, MIT and UMass Amherst, strengthening the relationship between the three labs and between students and faculty. Students, especially women and minority students, are encouraged to participate through existing courses, departmental advising activities and other geoscience departments. Students from underrepresented groups are reached through the Boston College AHANA (African-American, Hispanic, Asian and Native American) student office and the McNair program for undergraduates who are low-income and first-generation college participants, and/or part of underrepresented groups.
Funding for this project is provided by the NSF EAR Tectonics Program, with support from the NSF EAR EarthScope and Education and Human Resources Program.
