Carmichael — a geochemist, a National Geographic Explorer and a professor in App State’s Department of Geological and Environmental Sciences (GES) — specializes in Devonian period research, studying the causes and effects of mass extinction events that occurred 350–417 million years ago. In 2018, Appalachian State University geology professor Dr. Sarah Carmichael, App State students and other members of the DAGGER (Devonian Anoxia, Geochemistry, Geochronology and Extinction Research) team traveled to Mongolia to study late Devonian extinction events. Dr.