Geoscience Reference
In-Depth Information
Moscow just before the Second World War and under some pressure
confessed to being a spy. He was repatriated to Germany and eventually
became a professor in Bern. The dating methodology established at
this time is now known as the Holmes-Houtermans Model. In 1956
Holmes reported a date of 3,450 million years for a rock collected at
Monarch Reef, East Champ d'Or in the famous Witwatersrand district
of South Africa. In his 1960 timescale Holmes corrected a number
of errors that he had discovered in his 1947 scale. A number of rocks
collected from the Appalachian Mountains in the eastern United
States were found to be Devonian and not Ordovician as previously
thought. He also pushed the base of the Cambrian back by 90 million
years to 600 million years: today this has been reduced to 542.5
million years. However, setting aside this minor adjustment of 57.5
million years it is a remarkable testament to the labours, accuracy and
tenacity of Arthur Holmes that his timescale of 1960 is so similar to
that published in 2004.
Holmes was a giant in the world of radiometric dating and its
application to the geological time and the geological column. He
served as a member of two committees of the National Research
Council in Washington: the 'Subsidiary Committee on the Age of
the Earth', which reported in 1931 (Holmes contributed the lion's
share of the report); and the 'Committee on the Determination of
Geological Time' which reported in 1934. In 1956 he received both
the Wollaston Medal from the Geological Society of London and the
Penrose Medal from the Geological Society of America, the highest
awards both bodies could make, and he shared the important Vetlesen
Prize in 1964. However, as Cherry Lewis has documented, Alfred Nier
bestowed a far greater compliment on Holmes when he described his
as the 'Father' of geological timescales. A simple but fitting tribute to a
lifetime's work.
