Luminescence dating of Holocene sedimentary deposits on Romo, a barrier island in the Wadden Sea, Denmark

This study presents an Optically Stimulated Luminescence (OSL) based chronology for the evolution of the barrier island Romo and related back-barrier lagoon deposits in the Danish Wadden Sea. The chronology is constructed using 78 quartz OSL ages obtained using a Single Aliquot Regenerative dose (SAR) protocol; samples were retrieved from seven sediment cores, each up to 25 m long, taken from locations on the island and within the back-barrier lagoon. The reliability of the OSL results is assessed using preheat plateaus, thermal transfer tests, and dose recovery measurements, and by comparison with independent age control. The OSL ages compare favourably with three C-14 age estimates, and range between 220 +/- 20 and 15 800 +/- 1200 years. Romo appears to have developed as a progradational barrier system, and the island appeared for the first time approximately 8000 years ago. It then gradually expanded towards the west, north and south as a result of an abundant sediment supply. Luminescence dating is concluded to be well-suited for establishing precise and accurate chronologies for barrier island deposits, and the technique has provided an excellent basis for the reconstruction of barrier island evolution.