varve

American  

[vahrv] / vɑrv /

noun

Geology.

1. (in lake sediments) an annual deposit usually consisting of two layers, one of fine materials and the other of coarse.

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varve British  

/ vɑːv /

noun

1. a typically thin band of sediment deposited annually in glacial lakes, consisting of a light layer and a dark layer deposited at different seasons

2. either of the layers of sediment making up this band

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varve Scientific  

/ värv /

1. A layer or series of layers of sediment deposited in a body of still water in one year. Varves are typically associated with glacial lake deposits and consist of two layers—a lower, light-colored layer that consists primarily of sand and silt, and a darker upper layer that consists primarily of clay and organic matter. The lower layer is typically deposited in the summer by the rapid melt of glacial ice, and the upper layer is usually deposited in the winter by the slower settling of sediment through calm water. The thickness of the layers in a varve varies depending on the proximity to the margin of the glacier, with thicker layers forming closer to the glacial margin and thinner layers forming farther away from it. Varves have been used, like tree rings, to measure the ages of glacial deposits from the Pleistocene.

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Etymology

Origin of varve

First recorded in 1920–25, varve is from the Swedish word varv a round, (complete) turn