A06_P09

Mortar dating of the Stari Most bridge at Otres, Croatia, using data extrapolation

Sironić A¹,  Alajbeg A², Cherkinsky A³, Borković D¹, Barešić J¹, Krajcar Bronić I¹

¹Ruđer Bošković Institute, Zagreb, Croatia, ²Museum of Croatian Archaeological Monuments, Split, Croatia, ³Center for Applied Isotope Studies, University of Georgia, Athens, United States of AMerica

Many different approaches exist to radiocarbon dating of mortar, and there is still no universal recipe that would work in all cases. We experimented with data extrapolation from the dates of CO₂ fractions collected by sequential dissolution. The method was modelled after data obtained from two laboratory mortars. Here we use the same method for dating the archaeological site – the Stari Most (Old bridge) at Otres, Croatia.

The arch of the bridge is still partially preserved, making it possible to walk over the Otres creek even today. Based on cadastral and archive data it can be ruled out that the bridge was built after the beginning of the 19th century. A considerable number of stone bridges in the southern Croatian region Dalmatia were built during the Ottoman rule (16th-18th century), but the way of its construction reveals that the Stari Most bridge does not belong to this period either. Since Roman stone bridges were also built differently, the most probable possibility remains that the Stari Most at Otres is medieval.

The preliminary dating of the bridge places it from the 9th to the 13th century. The preliminary dating correlates the bridge to the neighboring Otres-Crkvina archaeological site, where most of the activities took place between the 9th and 15th centuries. This is the first attempt to date this arch bridge.