Last Glacial Period River, which in turn was formed during an earlier glacial period. In its retreat, the Wisconsin Episode glaciation left terminal moraines that form Long Island, Block Island, Cape Cod, Nomans Land, Martha's Vineyard, Nantucket, Sable Island, and the Oak Ridges Moraine in south central Ontario, Canada. In Wisconsin itself, it left the Kettle Moraine. The drumlins and eskers formed at its melting edge are landmarks of the Lower Connecticut River Valley. In the Sierra Nevada, there are three named stages of glacial maxima (sometimes incorrectly called ice ages) separated by warmer periods. These glacial maxima are called, from oldest to
Glacial erratic boulders of Estonia believed they had been carried by icebergs. However, in the following years of the 19th century the glaciation theory slowly gained the ascendancy. Glacial erratic boulders of Estonia Glacial erratic boulders of Estonia are large boulders of rock which have been formed and moved into Estonia by glacial action during previous ice ages. Before the takeover of Estonia by the Soviet Union, these large boulders were a symbol of national identity. They are now registered and protected by the Estonian government. These boulders are found in especially large quantities in Estonia. Most of the boulders greater than in circumference found