[2] Thomas George Vallance grew up in Sutherland, New South Wales (NSW) and in 1945 matriculated at Sydney's Canterbury Boys' High School.
In 1954 he was appointed the USYD's petrology lecturer, as the successor to Harold Rutledge (1920–1954),[1] who died in the 1954 BOAC Lockheed Constellation crash.
In May 1957 he married the geologist Hilary Brinton Krone in a ceremony at Sydney's Christ Church St Laurence.
This research contributed to understanding the mechanisms of hot water circulation through the oceanic basaltic crust.
In 1967 he was a founding member of the International Commission on the History of Geological Sciences (INHIGEO).
[1] He wrote the chapter Foundation of the book Rocks, Fossils, Profs: Geological Sciences in the University of Sydney, 1866–1973.