THE HUNTER-GATHERER COMMUNITIES FROM UPPER BIEBRZA BASIN - ENVIRONMENTAL CONTEXT. CASE STUDY FROM LIPOWO SITE (NE POLAND)

Abstract

Study area is located in NE part of Poland in middle Biebrza Basin. Relief of this region formed during Middle Polish (Saalian) Glaciation – Warta Stage. The Biebrza is underfit river with vast peat-bogs on its valley floor. Geological, geomorphological and archaeological studies were conducted at Lipowo site in 2016 excavation season. A beginning of peat accumulation in the valley floor was radiocarbon dated at 8490±80 BP (MKL-3275) 7658-7347 cal. BC. At the similar time was cut off the Biebrza riverbed near a sandy elevation. Cone from the silty sands in the bottom of this abandoned channel was radiocarbon dated at 8330±120 BP (MKL-3277) 7577-7083 cal. BC. Both these occurrences, a rise of ground water level and channel change, could be connected with climatic changes cool and humid phase at the beginning of Atlantic. Results of studies at Lipowo and other sites in Biebrza valley floor indicates some periods of climatic changes and an increase of morphogenetic processes activity. Climate fluctuations correlate very well with flood phases distinguished in Central European river valleys.