Karl Karekin Turekian, Sterling Professor of Geology and Geophysics Emeritus and Senior Research Scientist at Yale University, passed away on March 15, 2013, at Connecticut Hospice in Branford. Professor Turekian was born on October 25, 1927, in New York, New York. He was the only child of Vaughan Thomas and Victoria Turekian, survivors of the Armenian Genocides of 1896 and 1915. He earned his B.A. degree in chemistry from Wheaton College in Illinois, with interruption for military service in the U.S. Navy during World War II. He received his M.A. and Ph.D. degrees from Columbia University. Professor Turekian joined the faculty at Yale University in 1956 as the University's first geochemist, and he remained on the Yale faculty for his entire career of 57 years. At Yale, he served as Chairman of the Geology and Geophysics Department for two terms and held endowed Chairs as the Henry Barnard Davis Professor, the Benjamin Silliman Professor, and as the Sterling Professor of Geology and Geophysics. Professor Turekian also served as Curator of Meteorites and Planetary Science in the Peabody Museum, and he was Director of the Yale Center for the Study of Global Change and the Yale Institute for Biospheric Studies. He was a member of the Council on Archeological Studies and chaired the Yale Studies in the Environment Program. He was a member of Yale's Elizabethan Club. Professor Turekian had a long association with Berkeley College at Yale, where he served as Executive Fellow. He and his wife, Roxanne, were the first married couple who were allowed to live in one of Yale's residential colleges. Professor Turekian enjoyed an extremely productive career as a geochemist. His scientific research centered on the application of natural radioactive and radiogenic isotopes to the study of Earth, its atmosphere and oceans, with special focus on understanding the processes and impacts of change over time. He explored subjects as diverse as circulation of Long Island Sound, acid rain, climate change, sediment accumulations, cosmic dust flux to Earth, and the composition of the Earth's crust, among others. Studies in his laboratory also focused on determining the growth rates of marine organisms and the origins of the Earth's atmosphere. Professor Turekian was part of the initial team of scientists who studied the moon rocks brought back during the Apollo space missions. Professor Turekian was the author of five books and hundreds of articles that were published in international journals and professional volumes. He edited treatises, encyclopedias and handbooks on geochemistry and ocean sciences. He also served as editor for some of the top journals in his field. Professor Turekian performed exemplary service to the profession. When he began his career at Yale, he served as president of the Yale chapter of Sigma Xi. He served on the U.S. National Committee on Geochemistry, the Climate Research Board, the Ocean Science Board, the U.N. Council on the Scientific Aspects of Marine Pollution, and several committees and panels for the National Academy of Sciences, the National Research Council, and the National Science Foundation. He was president of the Geochemical Society, and an active member of the American Geophysical Union and the Geological Society of America. Professor Turekian has been richly recognized for his contributions to science. He is a member of the National Academy of Sciences, and a fellow of the American Association for the Advancement of Science and the American Academy of Arts and Sciences. He received an honorary doctoral degree from the State University of New York at Stony Brook. He was awarded the V. M. Goldschmidt Medal of the Geochemical Society, the Maurice Ewing Medal of the American Geophysical Union, and the Wollaston Medal of The Geological Society of London. Early in his career, he was a Guggenheim Fellow at Cambridge University, and later he was a Sherman Fairchild Distinguished Scholar at California Institute of Technology. Most recently, in February of this year, Professor Turekian received the William Clyde DeVane Medal for distinguished teaching and scholarship from the Yale College Phi Beta Kappa chapter. Professor Turekian was known for his legendary 'coffee hour' at Kline Geology Laboratory at Yale, where ideas flowed freely and were debated with verve. He took great joy in engagement with his students and his colleagues from around the world. He was a deeply committed Christian, and his Christian faith guided all parts of his life. He is survived by his wife, Roxanne; his children, Karla Ann Turekian and Vaughan Charles Turekian; his daughter-in-law, Heather Leigh Turekian; his grandchildren, Aleena Marie Turekian and Charles ('Chip') Henry Turekian; and many cousins, nieces and nephews. A private graveside service will be held at Grove Street Cemetery in New Haven. A celebration of Professor Turekian's life will take place in the future. Donations in Professor Turekian's memory may be made to the Armenian Missionary Association of American 31 West Century Road, Paramus, NJ, 07652; Children's Hospital Foundaiton 111 Michigan Avenue, NW, Washington, DC 20010; or CT Hospice 100 Double Beach Rd., Branford CT, 06405. Beecher & Bennett, 2300 Whitney Ave., Hamden in care of arrangements.