Luminescence dating of coastal sediments from the Baltic Sea coastal barrier-spit Darss-Zingst, NE Germany

This study presents the first optically stimulated luminescence (OSL) dating application of young Holocene sediments from the coastal environment along the German Baltic Sea at the barrier-spit Darss-Zingst (NE Germany). Fifteen samples were taken in Zingst-Osterwald and Windwatt from beach ridges to reconstruct the development of the Zingst spit system and separate phases of sediment mobilisation. The single-aliquot regenerative-dose (SAR) protocol was applied to coarse grain quartz for OSL dating. The reliability of OSL data was tested with laboratory experiments including dose recovery, recycling ratio and recuperation as well as the stratigraphy. We conclude that the sediment is suitable for OSL measurements and the derived ages are internally consistent as well as in agreement with the existing stratigraphy and the geological models of sediment aggradation. The beach ridges at Zingst-Osterwald aggregated ∼ 1900 to ∼ 1600 years ago before the alteration of the sediment system related to the late Subatlantic transgression and the closing of the coastal inlets. The sediment of Windwatt area was deposited after the transgression and the ages can be subdivided into four groups ∼ 900, ∼ 500, 260-320, and ∼ 40 years ago. It is assumed that the ages of ∼ 500 years (1500 AD) and between 260 and 320 years ago (1680-1750 AD) represent the phases of sediment mobilisation related to colder and stormier climatic conditions as well as regressive sea level conditions during the Little Ice Age (1350-1900 AD). The subrecent age estimate of ∼ 40 years demonstrates that the sedimentation processes in the Windwatt area are still active and might be related to a storm surge and sediment overwash in the 1960s. This study confirms prior chronological investigations in other coastal regions (e.g. North Sea) that OSL has a great potential to provide a reliable chronological frame in coastal areas.