Frank S. Spear

Frank S. Spear is an American metamorphic petrologist based at Rensselaer Polytechnic Institute since 1985, after earlier posts at the Carnegie Institution own Geophysical Laboratory and the Massachusetts Institute of Technology, who earned his doctorate at UCLA under W. Gary Ernst. He pioneered the quantitative analysis of the pressure-temperature-time histories of metamorphic rocks and their application to tectonic studies, and authored the influential 1993 textbook Metamorphic Phase Equilibria and Pressure-Temperature-Time Paths, known in the field as the Big Blue Book. He received the Dana Medal in 2008, the Murchison Medal in 2012 and the Walter H. Bucher Medal in 2024. He received the Penrose Medal in 2026.