Holocene development of the Caorle Lagoon, Northeast Italy

Abstract

Foraminferal analysis, sedimentological descriptions, granulometry and radiocarbon dating of five sediment cores enabled a Holocene reconstruction of the Caorle lagoon (Northeast Italy). Foraminifera define five biozones that formed since the Last Glacial Maximum. From 8 ka to at least 6 ka, the region developed from a drowned fluvial plain into a marsh (in biozone Z) and then into a lagoon with barrier islands. The landwards part of the lagoon first was dominated by the Tagliamento river, then became increasingly marine (in biozone Y) and then brackish in biozones X and W. After an eastward shift of the course of the Tagliamento, the river became of significant influence again after it was re-introduced into the area of interest after 3 ka, observed in biozone V. This study provides a comprehensive picture of the past development of the Caorle lagoon under relative sea level rise, which may further our understanding of the development of the region and of the changes coastal systems face due to future sea level rise.