In search for an island – Non-invasive, geoarchaeological investigations in Bruszczewo microregion (Central-western Poland)

•Bruszczewo site witnessed the existence of a lake during the prehistory.•LIDAR data indicate a presence of the esker in the center of palaeolake.•Geoarchaeological research revealed presence of changing environment on the esker.•Surface survey indicated prehistoric pottery presence on the esker.•The dry event on the esker might be attributed to Bronze and Early Iron Ages.•Geoarchaeological research contributed to reveal the wetland settlement archaeology. Middle part of the Samica Valley in Western Poland, also known as the Bruszczewo microregion, witnessed several occupational phases during the prehistoric times. The archive geoarchaeological research documented presence of the lake in the past which had demise around 250 BCE and it was overgrown by peat deposits. During the LIDAR elevation model analysis a ridge in the central part of the basin was detected and hypothesized as an esker and a probable island during the lake presence. The geoarchaeological research was undertaken in order to verify the potential esker as an island on the lake during prehistoric periods. Aerial and satellite imagery combined with magnetometry, surface survey, drillings and comparison to earlier research provided data supporting the presence of dry episodes in the stratigraphy of the esker. This events might be attributed to the Early Bronze Age when the fortified settlement of Bruszczewo was functioning as well as during the Late Bronze Age and Early Iron Ages.