born Feb. 12, 1813, Utica, N.Y., U.S.
died April 14, 1895, New Haven, Conn.
U.S. geologist, mineralogist, and naturalist.
He graduated from Yale University in 1833. He joined a U.S. exploring expedition to the South Seas (1838–42), acting as a geologist and zoologist. His contributions to the American Journal of Science stimulated U.S. geologic inquiry. His research into the formation of the Earth's continents and oceans led him to believe in the progressive evolution of the Earth's physical features over time. By the end of his life he also came to accept the evolution of living things, as articulated by Charles Darwin . During his lifetime, and largely under his leadership, U.S. geology grew from a collection and classification of unrelated facts into a mature science.