Richard Foster Flint, compiler of the first map of Connecticut's glacial geology.

Percival carried out his mapping as an observer rather than a theorist, preserving his work from the contortions of preconceived notions.

Tracking the Ice Sheet

For many years, our knowledge of Connecticut's glacial drift lagged sadly behind that of the bedrock. A few geologists dug a few holes and made a few maps, but the first systematic survey awaited the 20th century. Percival, too, made some observations on the origin and nature of Connecticut's "diluvium," as it was called, but he did not make a map. As he was writing before the arrival of Agassiz with his glacial theories, Percival ascribed much to the inundation of the earth by "currents, sweeping over the general surface * "' He was careful, however, not to draw a connection between these currents and Noah's flood; as always, Percival was cautious about adopting the scientific dogma of his day.

Surprisingly, the acceptance of the glacial theory during the mid19th century did not lead immediately to detailed mapping of Connecticut's drift. That job awaited Richard Foster Flint (1903-1976), probably the most influential glacial geologist of the 20th century. A tall and articulate man, Flint was a famous teacher who trained many of the best of the current generation of geologists. His eloquence made him a persuasive advocate and his views dominated the study of glacial geology in Connecticut for many years. Between 1927 and 1930, Flint single-handedly put together the first glacial map of the state, a testament to the tireless energy of this insightful geologist.

Flint's pioneering map, in contrast to Percival's, was in part an interpretive work. Rather than simply noting what he saw - sand here, gravel there, till somewhere else - Flint in addition tried to fit the observations to a theory. In many ways this approach is more useful than a purely observational one because it tells a comprehensible story. But it is also an approach destined for controversy as new data come in and opinions change. Today, many glacial geologists disagree with the interpretive elements of Flint's mapping.

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