Postdoctoral Fellowship: EAR-PF: The Thermal Evolution of Orogenic Mid-Lower Crust in the Late Paleozoic Appalachian Orogen

Molitor, Zachary, Somerville MA

Investigators

Abstract

Dr. Zachary Molitor has been awarded an EAR Postdoctoral Fellowship to conduct research and professional development activities under the mentorship of Dr. Jay Ague at Yale University. The temperature inside of the Earth affects natural phenomena like earthquakes and volcanic eruptions. But we do not understand exactly how hot it gets at certain depths below the surface. The Appalachian mountains contain rocks that were once deep below the Earth’s surface. By studying the temperature of these rocks from Earth’s past we can better understand the temperature inside of the Earth today. This work will also fund a summer research experience for an undergraduate student, science outreach to local schools, and the creation of a discussion group for LGBTQ+ issues. These programs will directly address the well-established lack of diversity and inclusion in the sciences. To achieve a greater understanding of the behavior of Earth’s lithosphere, or outermost rigid layer, we must have a detailed understanding of the thermal state and evolution of the lithosphere. In particular, the thermal state and evolution of the lithosphere in plate boundary regions is fundamental to our understanding of lithospheric deformation on the modern Earth. The New England Appalachians expose a relatively continuous suite of rocks exhumed from the deep crust (>15 km) over hundreds of millions of years. By studying this extensive exposure, the researchers will use a combination of petrogenetic modelling of whole rock compositions and observed mineral assemblages, diffusion modelling of garnet and rutile compositions, and monazite and zircon geochronology to constrain the thermal state and evolution of the deep lithosphere during Appalachian orogenesis between ~400-250 Ma. With constraints on the past thermal state of the deep crust from the Appalachians, workers will then construct a model for the thermal evolution of the orogenic crust and compare the model to existing work in modern systems. This model will inform future studies of deformation in modern mountain belts such as the Tibetan-Himalaya and the Western United States. Three broader impacts initiatives included with this work will seek to improve inclusion in the geosciences by taking a multifaceted approach to broadening participation at the K-12, undergraduate, and faculty and staff levels. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.