Ancylus Lake

Ancylus lake is a name given by geologists to the body of fresh water that replaced the Yoldia Sea after the latter had been severed from its saline intake across central Sweden (with the eastern end of the channel near present Stockholm) by the isostatic rise of south Scandinavian landforms. The dates are approximately 9500-8000 BP calibrated, during the full Boreal period. The lake became Littorina Sea when rising oceanic levels broke through the Great Belt.

The lake was named by Gerard de Geer after Ancylus fluviatilis, a gastropod found in its sediments.