Methodological approach for dating harbor sediments by using luminescence datinga case study in Ephesus, Western Turkey

For this study, a 15-m sediment core from the Roman harbor of Ephesus has been dated with the luminescence technique. C-14 age estimates from the same and a neighboring core were used for comparing and validating the luminescence dating results via a single aliquot regenerative dose (SAR) protocol: infrared stimulation of polymineral and blue stimulation of quartz. The results reveal new insights into the deposition of the sediments of the Roman harbor from 2000 BC to AD 1500 approximately. Some samples showed incomplete bleaching. The difference between the polymineral and the quartz techniques described the bleaching condition before burial. When both approaches give consistent ages, complete bleaching can be assumed. Consistent ages were further applied to the Bayesian age-depth model and discussed within the archeological context. Based on the Bayesian age-depth model, a high sedimentation rate of ca. 65mm/year was calculated for the period of similar to 700-400 BC suggesting a fast advance of the delta front. However, other age estimates suggest a fast advance for the period 200 BC to ca. AD 100. This is probably due to incomplete bleaching of the luminescence samples and the use of bulk samples for C-14 for this new study. Comparing the results with nearby cores suggests that dredging was conducted in the southern part of the Roman harbor at a depth of ca. 5m b.s.l