Reginald Aldworth Daly (March 18, 1871 – September 19, 1957) was a

Canadian Canadians (french: Canadiens) are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of ...

geologist A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althoug ...

Biography

Reginald Daly was educated at the University of Toronto, where geologist A.P. Coleman persuaded him away from teaching mathematics and into Earth Sciences. He attained his PhD at Harvard, and did postgraduate work in Germany and France. After working as a field geologist for the

International Boundary Commission The International Boundary Commission (french: Commission de la frontière internationale) is a bi-national organization responsible for surveying and mapping the Canada–United States border. The commission was created in 1908 and made permanen ...

, he was a professor, and headed the Department of Geology at Harvard University from 1912 until 1942. Daly was president of

The Geological Society of America The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitchco ...

in 1932. For the Boundary Commission, working in six field seasons, Daly mapped the border from the Pacific Ocean to the Great Plains, a rugged swath long and wide – an area of about . He documented the geology alone, but had the help of one field assistant and numerous wranglers and porters. He collected 1,500 rock specimens and made 960 thin sections, using a German polishing technique he learnt as a student. The project also included 1,300 photographs, dozens of lake soundings, stratigraphic and structural mapping, petrology, and morphology. In 1912, he filed his final report with the

Geological Survey of Canada The Geological Survey of Canada (GSC; french: Commission géologique du Canada (CGC)) is a Canadian federal government agency responsible for performing geological surveys of the country, developing Canada's natural resources and protecting the e ...

, a massive 3-volume tome he called ''North America Cordillera: Forty-Ninth Parallel.'' This work along the 49th parallel led him to formulate a theory of the origins of igneous rocks, and later publish his seminal work ''Igneous Rocks and Their Origin'' in 1914. According to Daly's biographer, James Natland, Daly was an early proponent of Arthur Holmes' and Alfred Wegener's

continental drift Continental drift is the hypothesis that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. The idea of continental drift has been subsumed into the science of pl ...

theory. Daly summarized his ideas in his 1926 book, ''Our Mobile Earth,'' which included on the title page small print adopted from Galileo: '' E pur si muove''. Daly's theory on continental displacement was based partly on the idea that after the Moon was ejected from the Earth, continental movement was an inevitable part of rebalancing the planet; he also suggested that continental material accruing near oceans eventually slips, and forces continents to creep along. He expanded this notion in ''Strength and Structure of the Earth,'' in 1940, where Daly anticipated aspects of

plate tectonics Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large ...

, including introduction of a " mesospheric shell" and a slippery vitreous basaltic substratum. Daly also proposed the impact theory of lunar creation in 1946, which countered two prevailing notions: George Darwin's hypothesis that the Moon spun out of the primordial Earth due to centrifugal force; and, another fashionable theory that the Moon was a captured wayward asteroid. Daly applied Newtonian physics to make his point, which was later validated.

Family

In 1903, Daly married Louise Porter Haskell, daughter of Alexander Cheves Haskell and Alice Van Yeveren, and elder sister of Mary Elizabeth Haskell. After their marriage, Louise accompanied Daly on his travels, and in the field, as an assistant. She did much of the work in preparing and editing his manuscripts and books, and Daly's 1914 book on 'Igneous Rocks and their Origin' is dedicated to her; his 'inspiring fellow worker'.

Awards

In 1909, Daly was elected a member of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

. Daly was awarded the

Penrose Medal The Penrose Medal was created in 1925 by R.A.F. Penrose, Jr., as the top prize awarded by the Geological Society of America. Originally created as the Geological Society of America Medal it was soon renamed the Penrose Medal by popular assent of t ...

in 1935, the

Wollaston Medal The Wollaston Medal is a scientific award for geology, the highest award granted by the Geological Society of London. The medal is named after William Hyde Wollaston, and was first awarded in 1831. It was originally made of gold (1831–1845), ...

in 1942 and the William Bowie Medal in 1946. In 1950 he became foreign member of the Royal Netherlands Academy of Arts and Sciences. The potassium zirconium silicate mineral dalyiteDalyite
/ref> and craters on

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

and the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

are named in his honor. His Cambridge, Massachusetts, house (the Reginald A. Daly House) is now a

National Historic Landmark A National Historic Landmark (NHL) is a building, district, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Only some 2,500 (~3%) of over 90,000 places listed ...

References

Bibliography

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External links