What is a Varve?

A varve is an annual deposit of sediment forming distinct layers. Varves are found in the river and act as the lake records. If you look at the picture to the left you can see an example of varves. They were formed by the annual layering of lake sediments. During the summer the heavier pieces of silt and sand were carried into the lake with meltwater and deposited on the lake bottom. In the winter the lake would freeze, the water would be calm and the finer pieces of clay would settle to the bottom landing on top of the summer layer. One summer/winter layer is an individual varve and represents a year in the life of the lake.

In 1922 Ernst Antevs, a Swedish geologist, traveled to New England to count, measure and correlate varves from Glacial Lake Hitchcock and the surrounding glacial lakes in the Ashuelot, Merrimack and Hudson River valleys. He counted 4,100 individual varves within the Connecticut River valley indicating that Glacial Lake Hitchcock had existed for at least 4,100 years (Ridge and Larsen, 1990). Read more about Lake Hitchcock and the varves.

Explore more, if you are interested in viewing a new insect
found in the varves (varve midge) in the Connecticut River.