This lecture marks 100 years since publication of the first paper to use a radiometric method to date a rock.  Astonishingly, that paper was written by a young undergraduate studying at what is now the Royal School of Mines.  His name was Arthur Holmes.

The British geologist Arthur Holmes (1890 – 1965) was a pioneer of geochronology, who performed the first radiometric dating by the U-Pb method to measure the age of a rock.  In 1910, while still an undergraduate, a Devonian igneous rock from Norway was assigned an age of 370 Ma by the U-Pb method.  (‘The Association of Lead with Uranium in Rock-Minerals, and Its Application to the Measurement of Geological Time’, Proceedings of the Royal Society, Series A 85: 248–256, 1911).  Published at a time when the age of the Earth was in dispute, this result established Earth’s great antiquity compared to Biblical and other estimates.

In 1913, Holmes published the now-famous booklet ‘The Age of the Earth’, which established him as the world’s authority on geochronology. After receiving his PhD in 1917 and spending some time as Chief Geologist for an oil company in Burma, Holmes was appointed in 1924 to the position of Reader in Geology at Durham University.

In 1928, Holmes suggested slow-moving convection cells in the Earth’s mantle as a physical mechanism that could explain how the then unpopular theory of continental drift might work.  Eighteen years later, he was elected a Fellow of the Royal Society for his broad contributions to geology and a year later was appointed to the Chair of Geology at Edinburgh University, which he held until retirement in 1956.  His second famous book ‘Principles of Physical Geology’ was first published in 1944.