Landscape history since the Saalian Drenthe stadial in the Widawa Catchment Area in Silesia, Poland: A case study on long-term landscape changes

Abstract

With the pre-Roman Iron Age, approximately in the 2nd century BCE, a cluster of iron smelting sites began to develop in the catchment area of the Widawa River, located in the Old Drift landscape of northeastern Silesia, Poland. Before this area became an important local center for early iron smelting during the late pre-Roman Iron Age to the Roman period, its landscape had undergone distinct changes since it was covered for the last time by ice sheets during the Saalian Drenthe stadial. Besides climate driven environmental and landscape changes during the late Pleistocene and Holocene the area is influenced by a settlement history since the Mesolithic.In order to understand the holistic development of this pre-Roman Iron Age iron smelting cluster this paper investigates the late Pleistocene landscape history of the southeastern part of the Widawa catchment with a focus on study sites in the context of early human impacts. Therefore a multi-proxy approach was applied, integrating geomorphological mappings and sedimentological analyses (lithology, particle grain size, bulk parameters, total inorganic and organic carbon) of selected drilling transects, dated by AMS radiocarbon with archaeological records, geological and topographical data.The study area developed its present shape in six main phases: Subsequently to the last ice coverage (A), which extensively accumulated Saalian glacial till, the Widawa valley initially developed its present directionality (B). The subsequent valley formation is characterized by a succession of accumulation phases of glaciofluvial deposits of the Drenthe (C) and Warthe stadial (D) and fluvial deposits of the Weichselian glacial period (E) and the Holocene (F), which each were followed by a subsequent incision of the Widawa valley. First human impacts on the sediment budget are represented by alluvial fan deposits, which accumulated at the end of the 4th millennium BP. This alluvial fan, situated in the context of three prehistoric slag sites, shows a complex sedimentological succession of charcoal dated fan sediments that indicate a human impact on the landscape development during the pre-Roman Iron Age and the Roman period, pointing to a temporal and spatial context of early iron smelting.