born Sept. 12, 1811, Hingham, Mass., U.S.
died Aug. 7, 1898, Bethlehem, N.H.
U.S. geologist and paleontologist.
He made extensive explorations in the St. Lawrence valley while teaching at Rensselaer Polytechnic Institute (1832–36). In 1836 he was appointed state geologist for the Geological Survey of New York; his studies culminated in the massive Geology of New York (part 4, 1843), a classic in U.S. geology that introduced the geosynclinal theory of mountain building. He was state geologist of Iowa (1855–58) and of Wisconsin (1857–60). He served as director of New York State's Museum of Natural History (1871–98). His major later work was the huge Paleontology of New York (13 vol., 1847–94).