The Outwash Plain of the Rospuda River Valley – a Record of Depositional Environments

The Rospuda subglacial channel hosts not only deep ribbon lakes and the Rospuda River itself, but also an outwash plain. The paper deals with a lithofacies analysis of deposits from exposures within the Rospuda outwash plain. With the support of geomorphological and geological analyses, it has been found that the outwash plain formed along the Rospuda subglacial channel that was being exposed from under the ice cover. The lithological record of the Rospuda outwash plain shows a distinct division into a proximal and a distal zone. The deposits under study reveal a record of a break in basial sedimentation, when ice-wedge casts developed under conditions of periglacial climate. The development of the Rospuda outwash plain is linked with the ice-marginal zone of the Pomeranian phase, similarly to the Olecko-Rajgród outwash plain that is located to the west.