Late Palaeolithic settlement pattern in palaeogeographical context of the river valleys in the Koło Basin (Central Poland)

The palaeogeography of the mid-Warta River valley in the Koło Basin in the Alleröd and Younger Dryas periods is well recognised. Record of subfossil trees is evidence of the existence of the riparian pine-birch forest in the valley floor in the Alleröd/Younger Dryas transition and in the early Younger Dryas. In the late Younger Dryas, the flood activity increased, which resulted in covering the valley floor with a thick layer of sandy and silty sandy overbank alluvia. Traces of settlement of people of only one archaeological culture dated to the Late Palaeolithic are recorded in the Koło Basin – i.e. the Tanged Point Complex, called in Polish territories the Sviderian Culture. The sites are camp sites remnants of hunter–gathering groups of the Alleröd and the Younger Dryas. Most sites are situated on dunes, cover sands or edges and slopes of river terraces. This paper focuses on the settlement pattern and the raw material distribution which indicate a highly mobile life-style and significance of human contacts in the Younger Dryas. In the relatively stable environmental conditions of the late Alleröd and in the very beginning of Younger Dryas, when the area was covered by forest, the first Tanged Point Complex communities arrived. The forest landscape was rich in natural resources and suitable for hunting. Later in the Younger Dryas, a climatic change caused the increase of floods, permafrost reactivation and riparian forest extinction. Human groups moved away from the area. The occurrence of exotic raw material confirms migration of hunter groups in the late Younger Dryas in the latitudinal direction. Camp sites were situated on more elevated inland surfaces of terraces and dunes. Most probably at the end of the Younger Dryas, Sviderian hunters migrated from the Koło Basin and followed the herds of animals far north. After the stabilization of environmental conditions, hunters came back to the Koło Basin.