December 2025: Dating of the Osor Channel

For a long time, the widely accepted theory was that the Osor Channel was man-made and had been in use since at least Roman times. However, new project results indicate that the channel was formed naturally towards the end of the Bronze Age, rather than being created by human activity in the Iron or Roman Ages (Miko et al. 2025).

Correlating the seismic data with the sediment core data enabled the project team to understand how the Osor Channel formed. We suggested that the strong currents that followed the flooding of the strait between Cres and Lošinj had deposited sediments from the Lošinj Channel near Osor. These sediments were found, identified and dated. The increased concentration of certain elements, such as rubidium, zircon and chromium (which are used as indicators of weathering or dust transport), as well as the presence of ostracods, indicate that the connection between Osor Bay and the Lošinj Channel via the strait at Osor was established by 1.100 BC.

Map of the Lošinj Channel showing the current direction and the marked sampling point for the underwater core drilling near the western city limits of Osor.

29. December 2025