QUATERNARY STRATIGRAPHY, GEOMORPHOLOGY, AND GEOCHRONOLOGY IN NORTHERN POLAND: LANDSCAPE EVOLUTION IN THE SOUTHERN BALTIC SEA COASTAL REGION

The factors influencing environmental change and human activities along the southern coast of the Baltic Sea can be studied from the perspective of an interdisciplinary geoarchaeological approach focused on geomorphology, stratigraphy, and geochronology. Surficial mapping, stratigraphic trenches, and drill cores within the Wieprza and Grabowa river catchments (situated between coastal lakes Bukowo and Kopan) in Poland provide evidence of Late Glacial and post-glacial geomorphic and sedimentary processes. Interdisciplinary studies conducted as part of the Dabki archaeological site research document peat deposition over till, glacio-fluvial, and lake deposits; radiocarbon measurements indicate peat formed during the late Younger Dryas and early PreBoreal (ca. 10,050-9,970 yr BP; 11,813-11,240 yr cal. BP). Excavations reveal lithofacies variation within the sedimentary basin and prehistoric human activities ranging in age mainly from ca. 6,000-5,200 yr BP (7,200-5,900 yr cal. BP). The southern Baltic Sea coastline is dominated by beach and eolian sands. Peat deposits crop out in places, interbedded in the sands. West of the sand ridges, the coastal region consists of till, outwash, glacio-fluvial sediments and younger lacustrine, paludal, and alluvial deposits. Marshlands and low-lying wetlands (coastal mires, fens) are underlain by peat. Higher ground west of the Grabowa River is composed of till (ground moraine). Till is exposed on the coastline cliff south of Lake Kopan. A ridge separates the northeast side of Lake Bukowo from the sequence of sediments deposited north towards the Wieprza River and Lake Kopan. Small streams and a late Holocene drainage network of ditches occur within the peatbog plains developed in the sedimentary basin south and west of the town of Dabki. From a paleogeographic perspective, the Late Glacial and Holocene regressions and transgressions in the Baltic basin have influenced the location of the shoreline of the coastal zone. During the Holocene, sea level change and storm or tsunami events have impacted the coastline and led to flooding, erosion, and sediment deposition. The Pleistocene-Holocene geology of western-central Pomerania in Poland contains evidence of environmental change associated with deglaciation, climate change, and human activities. This project is funded by NCN Poland grant no. 2017/25/B/HS3/02385 to JK.