A. Gilbert Smith

Alan Gilbert Smith (24 February 1937 – 13 August 2017) was an English geologist, stratigrapher, and pioneer of plate tectonic reconstruction.

Education and career Smith was born in Watford, and went to school at Watford Grammar School for Boys. Smith went to university at St John's College, Cambridge, and graduated in 1959 with a B.A. in natural sciences. From 1959 to 1963 he was a graduate student in geology at Princeton University, where he completed a PhD thesis on the Structure and stratigraphy of the northwest Whitefish Range, Lincoln County, Montana under the supervision of John C. Maxwell (1914–2006) and Franklyn B. Van Houten In 1963, Smith was appointed as a research assistant to Edward Bullard in the Department of Geodesy and Geophysics of the University of Cambridge. In 1964 he was appointed a demonstrator in the same department, and lecturer in 1971. Smith retired in 2004. His doctoral students included Michael Welland.

Research Smith's Ph.D. thesis was a major contribution to stratigraphic understanding of the Belt Supergroup. and the geological timescale. has historic importance in the establishment of the validity of plate tectonics. According to Eldridge M. Moores, Smith's 1971 paper Alpine Deformation and the Oceanic Areas of the Tethys, Mediterranean, and Atlantic was "a major breakthrough in our views of the relationship between sea floor spreading, the then new-plate tectonics, and orogeny." the author of The Tectonic Plates Are Moving! (Oxford University Press, 2018). In 2003 Smith and co-author Kevin T. Pickering, proposed a unifying explanation for Earth's icehouse periods during the past 620 million years.

Family Smith's father was an engineer and inventor, who developed instruments for the Royal Navy during WWII.