Radioactivity and geological time
Studying physics and geology in London, Holmes began researching radioactive minerals. He linked mineral ages with stratigraphy, published The Age of the Earth in 1913, and continued refining geological timescales.
References: [1]
A mechanism for continental movement
After moving to Durham in 1924, Holmes supported continental drift. In a 1927 presentation he proposed that heat from radioactive decay could drive slow mantle convection, offering a possible mechanism for moving continents.
References: [1]
Teaching and synthesis
He became a professor at Edinburgh in 1943 and published Principles of Physical Geology in 1944. The textbook brought surface and interior processes together; a substantially rewritten second edition appeared in 1965.
References: [1]