Kayleigh M. Harvey
PhD Candidate at the University of Maryland working under the mentorship of Dr. Sarah Penniston-Dorland. Research interest include metamorphic petrology and subduction dynamics.
In some exhumed subduction interfaces, like the one in this image (Tiburon Peninsula, Franciscan Complex, California) mélange blocks of markedly different metamorphic grads are juxtaposed. Many argue that this is the result of large-scale mixing of these blocks at the subduction interface. However, in exhumed terranes like the Catalina Schist (Santa Catalina Island, CA), we see less evidence of this large-scale mixing process. My research attempts to address scales of and controls on tectonic mixing in exhumed terranes to gain insight into the process.
Figure from Bebout and Penniston-Dorland (2016). The characteristic "block-in-matrix" texture of a tectonic mélange is thought to be derived at the subduction interface as the result of mechanical and fluid-mediated disaggregation of material from both the down-going slab and overriding mantle during subduction and exhumation. Fluids at the interface interact with disaggregated blocks, forming a metasomatized "reaction rind." These reaction rims can then break off from the blocks, forming a fine-grained hydrated matrix.
Department of Geology | University of Maryland | 8000 Regents Dr. | College Park, MD 20742
© Kayleigh M. Harvey