G. Brent Dalrymple

Gary Brent Dalrymple, known as Brent Dalrymple, is an American geologist born in 1937 in Alhambra, California. His research addressed the history of Earth's magnetic field and the development of radiometric dating methods, and he wrote the books The Age of the Earth and Ancient Earth, Ancient Skies. He served as president of the American Geophysical Union from 1990 to 1992, was elected to the National Academy of Sciences, and received the National Medal of Science in 2003.