Thomas Henry Clark was a citizen of three countries; he was born in England, educated in the United States and worked largely in Canada.
Born in London on December 3, 1893, he emigrated to the U.S. and attended Harvard. He graduated in 1917 and when the U.S. entered the First World War, he enlisted in the U.S. Army Medical Corps and served in France.
After the war he returned to Harvard, and on obtaining his PhD, he accepted the offer of a teaching post in the Geology Department (now Earth and Planetary Sciences) at McGill in 1924. He stayed at McGill for the next 69 years, retiring in May, 1993.
Clark lectured in the Redpath Museum auditorium to students in first-year geology and in paleontology and stratigraphy. In fact, his wife, the late Olive Marguerite Melvenia Prichard, was a student in one of his first classes in Geology I. They married in 1927 and have a daughter, Joan.
It was Clark who personally collected many of the Redpath's fossils, including several dozen specimens from his 1924 trip to the Burgess Shale. On that expedition, he met the repository's discoverer, then head of the Smithsonian Institution Dr. Charles Walcott.
Eventually Clarke became director of the museum, a post he held until, as chair of the renamed Department of Geological Sciences, he moved to the new Physical Sciences Centre, now the Frank Dawson Adams Building.
In 1926 Clark embarked on a major project: mapping the geology of the Quebec Appalachians along the U.S. border in the Eastern Townships. Working from the Sutton-Dunham area towards Phillipsburg and Lake Memphre-magog, he published a series of papers over the next decade on the geology and paleontology of the Townships. These papers established him as a leading geologist in Canada and led to his election to the Royal Society of Canada 60 years ago.
This early work also provided much material for later field trips with students in the area. Clark used the Socratic method in his field trips, insisting that students look at the rocks and form their own conclusions as they answered his questions. Although these trips were superorganized, the days did not seem long enough for the professor, and he and his students were sometimes examining outcrops by the headlights of cars.
By 1937 the emphasis of his research had changed from the highly deformed and metamorphosed rocks of the Eastern Townships to the little deformed rocks of the St. Lawrence lowlands. After finding on Ile Jesus (now Laval) that early maps were incorrect, he proposed to the Ministère des Mines that a totally new map of the Montreal area should be produced and started that project in 1938.
He also began mapping the St. Lawrence lowlands from the Ontario border to Quebec City and publishing reports on each map area.
By the late '60s the development of Montreal and the drilling for the seaway and other projects meant that studies of the geology of the Laval and Lachine areas should be revised. Clark therefore undertook further field work, much of which involved keeping an eye on drilling activities in the lowlands for oil and gas and engineering projects. Cores from the St. Lawrence Seaway excavation were logged and representative sections stored for future research.
Author of more than 100 scientific publications, he was co-author with his McGill colleague, Professor Emeritus Colin W. Stearn of The Geological Evolution of North America, which quickly became the standard text in university-level geology. Clark received countless awards during his career, including the Harvard Centennial Medal, the Prix Grand Mérite Géoscientifique, the Logan Gold Medal and the Centennial Award from the Royal Society of Canada.
Despite his many accomplishments and distinctions, Clark's great love was teaching. In a 1993 interview with the Reporter at the time of his 100th birthday, he said, "I was never happier than when I was in front of a class. I never used notes and made an effort to look at every single person in the audience during the course of the lecture. I wanted to make it a personal affair."
From material provided by Professor Emeritus Colin W. Stearn