WILLIS, BAILEY

born May 31, 1857, Idlewild-on-Hudson, N.Y., U.S. died Feb. 19, 1949, Palo Alto, Calif. U.S. geologist known for his structural and geomorphological analysis of the Appalachian Mountains. Willis was a member of the U.S. Geological Survey from 1884 until 1916, when he became professor of geology at Stanford University, Palo Alto, Calif., where he retired as professor emeritus in 1922. His work included studies of denudation (a form of erosion) chronology in North and South America and Africa, model experiments of folding and deformation, paleogeographic mapping of North America, and theories of the differentiation of the Earth's crust. Willis wrote The Mechanics of Appalachian Structure; Living Africa; African Plateaus and Rift Valleys; Earthquake Conditions in Chile; Earthquakes in the Holy Land; and Geological Map of North America.