Allan Verne Cox (December 17, 1926 – January 27, 1987) was an American geophysicist. His work on dating geomagnetic reversals, with Richard Doell and Brent Dalrymple, made a major contribution to the theory of plate tectonics. Allan Cox won numerous awards, including the prestigious Vetlesen Prize, and was the president of the American Geophysical Union. He was the author of over a hundred scientific papers, and the author or editor of two books on plate tectonics. On January 27, 1987, Cox died in an apparent suicide. Biography Cox began studying chemistry at the University of California, Berkeley. However, after a single quarter he left school and spent three years in the United States Merchant Marine. He returned to Berkeley, but had so little interest in chemistry that his grades were too low to avoid being drafted into the United States Army. When he returned, he switched his major to geology. His research career in geology began in 1950 when he took a position as a field assistant to Clyde Wahrhaftig studying glaciation in the Alaska Range; the pair later had a long romantic relationship. For his graduate research at the University of California, Berkeley, Cox concentrated on rock magnetism with John Verhoogen as his supervisor. Verhoogen was one of the few geologists of the time who took the hypothesis of continental drift seriously. His stance made a deep impression on Cox. After receiving his Ph.D. in 1959, Cox joined the United States Geological Survey in Menlo Park, California. There he collaborated with another geophysicist, Richard Doell, on rock magnetism. The two were particularly interested in geomagnetic reversals. At the time, very little was known about the timing of reversals. The rock specimens they collected were too young (a few millions of years) to date accurately until the potassium-argon dating method was developed. Cox and Doell arranged for the USGS to hire Brent Dalrymple, a graduate from Berkeley with expertise in this method. The three succeeded in creating the first geomagnetic polarity time scale. This work made possible the first test, by Frederick Vine and Drummond Matthews, of the seafloor spreading hypothesis. Cox was hired as a professor at Stanford University in 1967. He became Dean of the School of Earth Sciences in 1979 and demonstrated a talent for administration that was widely acknowledged by his colleagues. Cox died in a bicycle accident, colliding with a large redwood tree after falling