Postdoctoral Fellowship: EAR-PF: How are sedimentary rocks incorporated into the lower continental crust? A petrochronological investigation of the Serre Massif, Calabria, Italy

Pennsylvania State Univ University Park, University Park PA

Investigators

Abstract

Earth’s lower continental crust (LCC) plays a key role in shaping our planet’s structure, chemistry, and landscape, but much about how it forms remains uncertain. Although many scientists think it is mostly made of dense, dark-colored igneous and metamorphic rocks, the discovery of sedimentary rocks deep in the crust suggests that lighter, more silica-rich materials may also be present. This project will investigate how sediments get buried deep enough to become part of the lower crust by studying a unique exposure of ancient deep crust called the Serre Massif in southern Italy. By combining field mapping, lab-based analysis, and geochronology (rock dating), this research will test different models for how sediments are moved and transformed deep underground. This work will not only improve our understanding of Earth's evolution but also create opportunities for students to gain hands-on experience in geoscience research. A paid undergraduate research assistant will be recruited, mentored by the Principle Investigator, and supported in presenting their work at a scientific meeting. These efforts aim to train the next generation of Earth science researchers by addressing financial, physical, and mentoring barriers in the discipline. Scientifically, this project will evaluate three competing hypotheses for sediment incorporation into the LCC: burial, tectonic underplating, and relamination. Each predicts different patterns in the timing and conditions of metamorphism. The Serre Massif, a well-preserved Variscan granulite terrane, provides an ideal natural laboratory to investigate these processes, as it retains prograde mineral assemblages, chemical zoning, and metamorphic ages. Field-based structural analysis will identify shear zones and fabrics associated with sediment transport. High-grade metamorphic conditions will be constrained using thermobarometry, Raman spectroscopy, and pseudosection modeling. U-Th/Pb dating and trace element analysis of zircon and garnet will provide temporal and geochemical data to reconstruct prograde P-T-t histories and evaluate age-depth relationships across the crust. Results will improve understanding of lower crustal formation processes and inform models of crustal recycling, geodynamic evolution, and seismic interpretation. The project will contribute to both scientific knowledge of lower crustal evolution, processes, and properties and to building the geoscience community of the future. 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.