Leon Silver (PhD '55), W. M. Keck Foundation Professor for Resource Geology, Emeritus, at Caltech, passed away on January 31, 2022. He was 96 years old.
Silver was born in Monticello, New York, on April 9, 1925. His father and mother emigrated from Russia and Poland, respectively, and met in Brooklyn. He graduated from high school in 1942, just months after the United States entered World War II. He joined the Navy Reserve while studying at the Colorado School of Mines and was called up to active service in 1943, having turned 18 three months earlier.
Through the V-12 Navy College Training Program, which paid the college tuition of engineering students who were expected to become officers at the end of their studies, Silver earned a bachelor's degree from University of Colorado in 1945. He served in the Navy until 1946, then earned a master's degree from the University of New Mexico in 1948 and a doctorate degree in geology and geochemistry from Caltech in 1955. During this time, he also worked at the United States Geological Survey (USGS).
After completing his doctoral degree, Silver began teaching at Caltech as an assistant professor of geology in 1955. He was promoted to associate professor in 1962, and earned tenure in 1965. He was named the W. M. Keck Foundation Professor for Resource Geology in 1983, and became emeritus in 1996.
When he started at Caltech, Silver served as geologist to the Institute's newly formed geochemistry group, which was led by the late Harrison Brown, professor of geochemistry. Silver studied geological formations in Arizona and the San Gabriel Mountains while continuing to consult for the USGS. He is perhaps most famous for his contributions to the Apollo program during the 1970s. He instructed Apollo astronauts on geology and lunar sample selection—including Apollo 17 astronaut and Caltech alumnus Harrison "Jack" Schmitt (BS '57)—and developed approaches for using isotope ratios for geochronology, the study of the age and history of rocks and sediments.
Silver also served on several federal advisory committees, including as chair of the Advisory Committee to the Office of Basic Energy Sciences of the Department of Energy from 1990–92. Throughout his career, he received numerous honors and awards, including a NASA Exceptional Scientific Achievement Medal and an American Institute of Professional Geologists Award for Professional Excellence. He was named a member of the National Academy of Sciences and a senior fellow of the Mineralogical Society of America, and served as president of the Geological Society of America in 1979.
In later years, Silver and other colleagues from Caltech's Division of Geological and Planetary Sciences led trips down the Colorado River for the Caltech Associates and alumni.
A full memorial story will follow at a later date.