THE NATURAL AND ANTHROPOGENIC EVOLUTION OF THE BIEBŁA RIVER VALLEY AND THE RECORD OF ENVIRONMENTAL CHANGES IN ITS ALLUVIA - PRELIMINARY RESULTS

Abstract

The studied Biebła river valley is located in NE Poland in the Podlasie Voivodeship. This left tributary of Brzozówka river has very anthropogenic transformed riverbed. It flows in depression of SW-NE orientation between the Goniądz Upland and Suchowola-Janów Upland. It is currently a peat plain. The aim of the research is to identify the changes in the paleoenvironmental conditions that occurred in the Biebła river valley. Four phases of the Biebła valley evolution could be distinguished: the Pleistocene erosion phase after the Warta Cold Stadial, transformation of river pattern from braided to meandering one in the turn of the Late Glacial and the Holocene, phase of intensive peat-bog development since Preboreal to Subboreal period and phase with anthropogenic catchment deforestation and an increase of overbank deposition in the peats on flood plain. Research on this tributary is carried out as part of a wider synthetic reconstruction of the environmental conditions of the mesoregion of the Bronze Age settlements, which functioned during the environmental transformations at the end of the Subboreal and beginning of the Subatlantic.

Keywords

• biebła valley
• podlasie
• palaeoenvironment