Abstract
Raised beach ridges are prograded sequences of wave-built deposits that may provide valuable information about past relative sea-level changes, climate change and coastal evolution. In the Limfjord in northern Denmark, the Early and Middle Holocene sea-level changes are well-constrained. However, our understanding of Late Holocene sea-level fluctuations is limited, and the exact period when the coastal barrier between the Limfjord and the North Sea formed remains uncertain. In this study, we use optically stimulated luminescence (OSL) dating to determine the age of raised beach ridges at Gjellerodde in the western part of the Limfjord. The OSL ages presented here indicate that the beach ridges formed during three periods at 3.3–2.7, 1.4–1.0, 0.2–0.1 ka. In addition our data suggest a c. 0.2 mm/yr relative sea-level fall during the Late Holocene. The three distinct periods of beach-ridge formation coincide with periods when the Limfjord was open towards the North Sea as documented in historical records and marine records. This suggests that OSL dating of beach ridges can be used as a potential indicator for determining when the connection between the Limfjord and the North Sea was open in the Late Holocene.
Publisher
Geological Survey of Denmark and Greenland
Reference39 articles.
1. Aitken, M.J. 1985: Thermoluminescence dating. London: Academic Press.
2. Ballarini, M., Wallinga, J., Wintle, A.G. & Bos, A.J.J. 2007: A modified SAR protocol for optical dating of individual grains from young quartz samples. Radiation Measurements 42, 360-369.
3. Bennike, O., Nørgaard-Pedersen, N., Jensen, J., Andresen, K. & Seidenkrantz, M.-S. 2019: Development of the western Limfjord, Denmark, after the last deglaciation: a review with new data. Bulletin of the Geological Society of Denmark 67, 53-73.
4. Bøtter-Jensen, L., Thomsen, K.J. & Jain, M. 2010: Review of optically stimulated luminescence (OSL) instrumental developments for retrospective dosimetry. Radiation Measurements 45, 253-257.
5. Branner, W. 1839: Sognekort, Tørring Sogn (Skodborg Herred) 1839. Historiske kort pa nettet. Nørresundby: Geodatastyrelsen.