Roman Ruins as an Experiment for Radiocarbon Dating of Mortar

The remains of Vindonissa, the Roman legionary camp in Switzerland, have been the subject of extensive archaeological studies. Knowledge of the building time plays a role in reconstructions of the history of this site. We radiocarbon dated mortar samples selected from one of the Roman monuments (Westtor) as well as a nearby Medieval monastery. 14 C ages obtained on the first fraction and second fraction of very short dissolution appear close to the expected Roman age of ∼2000 BP, while the monastery is dated to historic times, after AD 1308.