varve A banded layer of silt and sand deposited annually in lakes, especially near to ice sheets. The coarse, paler material is deposited in summer; the finer, darker material in winter. One varve consists of one light band and one dark band. Varves can be counted to calculate the age of glacial deposits (varve analysis, also called varve chronology or varve count). Since the pattern of thicknesses of successive varves is often distinctive, correlations can be made between widely separated deposits, using the same principle as that of dendrochronology.

varve A banded layer of silt and sand deposited annually in lakes, especially near to ice sheets. The coarse, paler material is deposited in summer; the finer, darker material in winter. One varve consists of one light band and one dark band. Varves can be counted to calculate the age of glacial deposits (varve analysis, also called varve chronology or varve count). Since the pattern of thicknesses of successive varves is often distinctive, correlations can be made between widely separated deposits, using the same principle as that of dendrochronology.

varve dating (geochronology) An absolute dating technique using thin sedimentary layers of clays called varves. The varves, which are particularly common in Scandinavia, have alternate light and dark bands corresponding to winter and summer deposition. Most of them are found in the Pleistocene series, where the edges of varve deposits can be correlated with the annual retreat of the ice sheet, although some varve formation is taking place in the present day. By counting varves it is possible to establish an absolute time scale for fossils up to about 20 000 years ago.