Speaker – Sarah George, UNC-Chapel Hill, Geology (host – M. Curry) 

Seminar Title – Subduction of thick oceanic crust: a key player in Earth surface processes along Cordilleran margins  Zoom

Asbtract – Subduction of thick oceanic crust is an important process that occurs along ~10% of Cordilleran margins, modifying the geometry of the subduction zone. This talk explores the earth’s surface responses to this deep-seated tectonic process across several modern zones in South America. In Peru, we present compiled geochronologic, geomorphic, and thermochronologic datasets which document arc shutoff, rock uplift, and shifts in drainage morphology during subduction of thick oceanic crust. In Colombia, we present geologic field datasets and landscape analysis that support connections between the formation of large river systems and changes in slab dynamics. Overall, we show that the subduction of thick oceanic crust promotes erosion, rock uplift, and drainage reorganization in the overriding continental crust.