The first record of red till lithotype in western Poland and its implication for glacial stratigraphy and palaeogeography

The first site in western Poland with a red till lithotype has been discovered in the Trzebnica Hills, southwestern Poland. This is a clay-rich, red till with dominant East-Baltic material (East-Baltic lithotypes). The red till forms the uppermost part of the Borowiec Till, a till from the Sanian 2 (Elsterian) Glaciation. Moreover, some Borowiec tills in the Barycz River valley (north) and the Prosna River valley (east) contain in their uppermost parts a dolomite-rich horizon, which, although only greyish-brown, also represents the East-Baltic till lithotypes. The late Elsterian ice sheet in Poland was developed as several ice-lobes with different ice dynamics. The lobes from western Poland advanced to their maximum extent earlier than the eastern lobes. In the latest phase of the glaciation, the western lobes retreated, while the eastern ones advanced from NE to SW. Their presence is proved by deposition of the Borowiec Till and East-Baltic till lithotypes.