Hatten Schuyler Yoder Jr.

Hatten Schuyler Yoder Jr. was an American geophysicist and experimental petrologist born March 20, 1921, in Cleveland, Ohio, who died August 2, 2003, in Bethesda, Maryland, and who earned degrees from the University of Chicago and the Massachusetts Institute of Technology before serving as the fourth director of the Carnegie Institution of Washington Geophysical Laboratory from 1971 to 1986. He conducted pioneering work on minerals under high pressure and temperature, advancing understanding of silicates and igneous rocks. He was elected to the National Academy of Sciences in 1958 and to the American Academy of Arts and Sciences and the American Philosophical Society in 1979, received the Arthur L. Day Medal of the Geological Society of America in 1962, the Roebling Medal in 1992, and the Wollaston Medal in 1979.