Born Jan. 14, 1890, in Hebbern; died Sept. 20, 1965, in Putney (London). British geologist and petrog-rapher. Fellow of the Royal Society of London (1942).

Holmes graduated from the University of London in 1909. From 1927 to 1943 he was a professor at the University of Durham, and beginning in 1943, he was a professor at the University of Edinburgh. His principal works dealt with the theory of measuring the absolute ages of rocks and of the earth as a whole. Holmes was the first to note the role played by ⁴⁰K in the heat balance of the crust. He demonstrated that tectonic-magmatic phenomena are linked to the upper 20–40 km of the earth’s mantle. Holmes was the author of works on the Precambrian of Africa and India and textbooks on physical geology and petro-graphic methods of studying rocks.