The development of periglacial sedimentation in the Wolica Valley (SE Poland) during the Weichselian Upper Pleniglacial

The development of the Weichselian Upper Pleniglacial periglacial sedimentation in the Wolica Valley was evaluated by means of geomorphological, geological and sedimentological investigation. Sediments of the medium (II) raised terrace, the surface area of which is a dominant element of the valley, were examined. The terrace has a complex structure comprising deposits of different age, lithology and origin. The basal part of the terrace is formed from terrace remnants from the Middle Pleniglacial and the phase before maximum cold of the Upper Pleniglacial. The base consists of sandy channel deposits and silty-sandy floodplain deposits. The upper part of the terrace is a thick series of deposits from the phase after maximum cold. It is built from slope, floodplain and channel deposits, as well as alluvial fans. The complexity of the structure results from the specific character of periglacial processes and their rhythmical course, as well as from the influence of local conditions. The deposits of the basal part of the terrace were shaped in a subpolar climate with maritime features, whereas the sediments of its upper part formed in continental subpolar climate. Local factors, such as: lithology of rocks in the river drainage basin, a dense network of valleys in the basin and alluvial fans, determined the suspension type of transport, the shape of the river channel and retention of a large amount of sediment in the Wolica drainage basin and on its valley-floor.